# Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Justin,

What do you mean with "transforms the solar heat gain"? The last thing I
heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate Solar
Heat Gain by itself, and the luminaire power will be defined from a
Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working
with integrated Thermal and Lighting simulations of spaces with controlled
Luminaires and Complex Fenestration Systems. I used Radiance and
EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my thesis,
or related information.

I wanted to contribute to OpenStudio, but my programming skills and lack of
time did not allow me.

Bye!

Germán

···

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have determined
that the three-phase method is probably going to be our best option. We're
looking to model the effects the dynamic glazing system would have on the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available to do
this and found "Challenges of Integrated Daylight and Electrical Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one of
the
most integrated and streamline options available for coupled daylight and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar heat
gain? The daylight is well studied and discussed, but I haven't been able
to
find out whether this method will discount the solar heat gain through the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors for
the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I don't
understand is if the OpenStudio simulation of Radiance and EnergyPlus
calculates the new solar heat gain (of the CFS) using Radiance or
EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If
OpenStudiodoes this already, maybe I'm just missing it and someone can
point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

···

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain <[email protected] > wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing I
heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate
Solar Heat Gain by itself, and the luminaire power will be defined from a
Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working
with integrated Thermal and Lighting simulations of spaces with controlled
Luminaires and Complex Fenestration Systems. I used Radiance andEnergyPlus, but no
OpenStudio. You (and anyone) can ask me for my thesis, or related
information.

I wanted to contribute to OpenStudio, but my programming skills and lack
of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have
determined
that the three-phase method is probably going to be our best option.
We're
looking to model the effects the dynamic glazing system would have on the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available to do
this and found "Challenges of Integrated Daylight and Electrical Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one of
the
most integrated and streamline options available for coupled daylight and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar
heat
gain? The daylight is well studied and discussed, but I haven't been
able to
find out whether this method will discount the solar heat gain through
the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors
for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

_______________________________________________
[email protected]

Although I have heard some things about calculating solar heat gains with
Radiance, I do not think OpenStudio does that... I did not do that, at
least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and
other shading devices, and also inserting the BSDF of a CFS, and it will
calculate the solar heat gains. My understanding is that the BSDF-based
modelling of a CFS will be accurate enough for performing the
calculation... maybe Radiance would be better for more complex handling
geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow you
to choose a "block beam radiation" algorithm. I guess that, from that, you
can report the VB position, and perform the lighting simulation in
Radiance, and choose the artificial lighting power for the luminaires, and
write them down in a schedule. Finally, you can go back to EnergyPlus, and
use the lighting power, and use it to control the internal gains caused by
the artificial lighting. *THIS WOULD BE VALID FOR THIS CASE. In my thesis
you might find how to do it with some other kind of shading device.*

I will attach my Thesis directly to you later.

Bye!

Germán

···

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I don't
understand is if the OpenStudio simulation of Radiance and EnergyPlus
calculates the new solar heat gain (of the CFS) using Radiance or
EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If OpenStudiodoes this already, maybe I'm just missing it and someone can point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain < > [email protected]> wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing I
heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate
Solar Heat Gain by itself, and the luminaire power will be defined from
a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working
with integrated Thermal and Lighting simulations of spaces with controlled
Luminaires and Complex Fenestration Systems. I used Radiance andEnergyPlus, but no
OpenStudio. You (and anyone) can ask me for my thesis, or related
information.

I wanted to contribute to OpenStudio, but my programming skills and lack
of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have
determined
that the three-phase method is probably going to be our best option.
We're
looking to model the effects the dynamic glazing system would have on
the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available to
do
this and found "Challenges of Integrated Daylight and Electrical
Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one
of the
most integrated and streamline options available for coupled daylight
and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar
heat
gain? The daylight is well studied and discussed, but I haven't been
able to
find out whether this method will discount the solar heat gain through
the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors
for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

haven't found any papers on how to integrate it within a whole-building
simulation yet, I'll keep looking. If anyone knows of a source it would be

EnergyPlus does have a nicely integrated venetian blind module, but
unfortunately that doesn't exactly represent the system we're attempting to
model. My project is similar but a bit more complicated in practice,
although it does also block direct beam, I'll need to think if this is
representative. We were imagining, creating a defined number of geometries
(representative of dynamic states), create the BSDF for each, and then
chose between them for various states of the annual daylight
simulation.Following
the three-phase method, with the integration of results in a whole-building
simulation.

From your suggestions, it appears as though the best solution to calculate

the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to
calculate the solar heat gain and then use Radiance (with OpenStudio) for
the Daylight and Lighting Load simulations. Though I'm guessing that
EnergyPlus cannot handle dynamic BSDFs for various CFS configurations
without some form of co-simulation. I'll have to read more into the methods
EnergyPlus uses to calculate the solar heat gain from a BSDF and determine
if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced
methods for integrating Radiance daylight and heat gain into whole-building
simulation from dynamic fenestration systems? Maybe I'm looking at the
problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your
SketchUp plug-in video earlier, very cool stuff.

Sincerely,
Justin

···

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain <[email protected] > wrote:

Although I have heard some things about calculating solar heat gains with
Radiance, I do not think OpenStudio does that... I did not do that, at
least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and
other shading devices, and also inserting the BSDF of a CFS, and it will
calculate the solar heat gains. My understanding is that the BSDF-based
modelling of a CFS will be accurate enough for performing the
calculation... maybe Radiance would be better for more complex handling
geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow you
to choose a "block beam radiation" algorithm. I guess that, from that, you
can report the VB position, and perform the lighting simulation in
Radiance, and choose the artificial lighting power for the luminaires, and
write them down in a schedule. Finally, you can go back to EnergyPlus, and
use the lighting power, and use it to control the internal gains caused by
the artificial lighting. *THIS WOULD BE VALID FOR THIS CASE. In my thesis
you might find how to do it with some other kind of shading device.*

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I don't
understand is if the OpenStudio simulation of Radiance and EnergyPlus
calculates the new solar heat gain (of the CFS) using Radiance or
EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If OpenStudiodoes this already, maybe I'm just missing it and someone can point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain < >> [email protected]> wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing I
heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate
Solar Heat Gain by itself, and the luminaire power will be defined from
a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis,
working with integrated Thermal and Lighting simulations of spaces with
controlled Luminaires and Complex Fenestration Systems. I used Radiance
and EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my
thesis, or related information.

I wanted to contribute to OpenStudio, but my programming skills and
lack of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a
basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have
determined
that the three-phase method is probably going to be our best option.
We're
looking to model the effects the dynamic glazing system would have on
the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available to
do
this and found "Challenges of Integrated Daylight and Electrical
Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one
of the
most integrated and streamline options available for coupled daylight
and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar
heat
gain? The daylight is well studied and discussed, but I haven't been
able to
find out whether this method will discount the solar heat gain through
the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors
for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

If the VB model does not work for you, you can allways dynamically modify
the BSDF by using the EnergyManagementSystem (EMS).

EnergyPlus calculates the SHG through a CFS by passing the beam radiation
through the BSDF you define in the IDF file. The diffuse radiation, I
understand, is averaged.

Calculating SHG using Radiance is something I would like to know of! if you
find anything, let me know.

THANKS

Germán

···

2014-03-11 16:06 GMT-03:00 Justin Shultz <[email protected]>:

haven't found any papers on how to integrate it within a whole-building
simulation yet, I'll keep looking. If anyone knows of a source it would be

EnergyPlus does have a nicely integrated venetian blind module, but
unfortunately that doesn't exactly represent the system we're attempting to
model. My project is similar but a bit more complicated in practice,
although it does also block direct beam, I'll need to think if this is
representative. We were imagining, creating a defined number of geometries
(representative of dynamic states), create the BSDF for each, and then
chose between them for various states of the annual daylight simulation.Following
the three-phase method, with the integration of results in a whole-building
simulation.

From your suggestions, it appears as though the best solution to calculate
the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to
calculate the solar heat gain and then use Radiance (with OpenStudio) for
the Daylight and Lighting Load simulations. Though I'm guessing that
EnergyPlus cannot handle dynamic BSDFs for various CFS configurations
without some form of co-simulation. I'll have to read more into the methods
EnergyPlus uses to calculate the solar heat gain from a BSDF and determine
if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced
methods for integrating Radiance daylight and heat gain into whole-building
simulation from dynamic fenestration systems? Maybe I'm looking at the
problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your
SketchUp plug-in video earlier, very cool stuff.

Sincerely,
Justin

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain < > [email protected]> wrote:

Although I have heard some things about calculating solar heat gains with
Radiance, I do not think OpenStudio does that... I did not do that, at
least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and
other shading devices, and also inserting the BSDF of a CFS, and it will
calculate the solar heat gains. My understanding is that the BSDF-based
modelling of a CFS will be accurate enough for performing the
calculation... maybe Radiance would be better for more complex handling
geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow
you to choose a "block beam radiation" algorithm. I guess that, from that,
you can report the VB position, and perform the lighting simulation in
Radiance, and choose the artificial lighting power for the luminaires, and
write them down in a schedule. Finally, you can go back to EnergyPlus, and
use the lighting power, and use it to control the internal gains caused by
the artificial lighting. *THIS WOULD BE VALID FOR THIS CASE. In my
thesis you might find how to do it with some other kind of shading device.*

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I
don't understand is if the OpenStudio simulation of Radiance andEnergyPlus calculates the new solar heat gain (of the CFS) using Radiance
or EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If OpenStudiodoes this already, maybe I'm just missing it and someone can point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain < >>> [email protected]> wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing
I heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate
Solar Heat Gain by itself, and the luminaire power will be defined
from a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis,
working with integrated Thermal and Lighting simulations of spaces with
controlled Luminaires and Complex Fenestration Systems. I used Radiance
and EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my
thesis, or related information.

I wanted to contribute to OpenStudio, but my programming skills and
lack of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a
basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have
determined
that the three-phase method is probably going to be our best option.
We're
looking to model the effects the dynamic glazing system would have on
the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available
to do
this and found "Challenges of Integrated Daylight and Electrical
Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by
Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one
of the
most integrated and streamline options available for coupled daylight
and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the
solar heat
gain? The daylight is well studied and discussed, but I haven't been
able to
find out whether this method will discount the solar heat gain
through the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors
for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

I'm responding to the "things about Radiance solar heat gain calcs" query. I
suspect you're looking for something along the lines of radiation maps?

I have not followed this closely enough to make any statements on how
portable/interoperable this would be to whole-building energy simulation
(e.g. E+).

···

--
Not sure if this is of any help though, as this is somewhat old now (7
years ago) and buried deep in ESP-r development branches:

... based on the Daysim/Radiance daylight coefficient (DC) approach and the
DDS format, there was work done to explore run-time coupling of detaiiled
tests. Results were quite promising, but I believe ESP-r development since
went down another route (i.e. avoiding dependence on external tools like
Daysim/Radiance). Nonetheless, it remains an example of how
simulation. I don't see why similar concepts couldn't rely on CFS/BSDF,
3-phase, 5-phase approaches. Anyways, the source code is open-source.

Denis Bourgeois PhD | [email protected]

2014-03-11 15:06 GMT-04:00 Justin Shultz <[email protected]>:

haven't found any papers on how to integrate it within a whole-building
simulation yet, I'll keep looking. If anyone knows of a source it would be

EnergyPlus does have a nicely integrated venetian blind module, but
unfortunately that doesn't exactly represent the system we're attempting to
model. My project is similar but a bit more complicated in practice,
although it does also block direct beam, I'll need to think if this is
representative. We were imagining, creating a defined number of geometries
(representative of dynamic states), create the BSDF for each, and then
chose between them for various states of the annual daylight simulation.Following
the three-phase method, with the integration of results in a whole-building
simulation.

From your suggestions, it appears as though the best solution to calculate
the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to
calculate the solar heat gain and then use Radiance (with OpenStudio) for
the Daylight and Lighting Load simulations. Though I'm guessing that
EnergyPlus cannot handle dynamic BSDFs for various CFS configurations
without some form of co-simulation. I'll have to read more into the methods
EnergyPlus uses to calculate the solar heat gain from a BSDF and determine
if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced
methods for integrating Radiance daylight and heat gain into whole-building
simulation from dynamic fenestration systems? Maybe I'm looking at the
problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your
SketchUp plug-in video earlier, very cool stuff.

Sincerely,
Justin

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain < > [email protected]> wrote:

Although I have heard some things about calculating solar heat gains with
Radiance, I do not think OpenStudio does that... I did not do that, at
least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and
other shading devices, and also inserting the BSDF of a CFS, and it will
calculate the solar heat gains. My understanding is that the BSDF-based
modelling of a CFS will be accurate enough for performing the
calculation... maybe Radiance would be better for more complex handling
geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow
you to choose a "block beam radiation" algorithm. I guess that, from that,
you can report the VB position, and perform the lighting simulation in
Radiance, and choose the artificial lighting power for the luminaires, and
write them down in a schedule. Finally, you can go back to EnergyPlus, and
use the lighting power, and use it to control the internal gains caused by
the artificial lighting. *THIS WOULD BE VALID FOR THIS CASE. In my
thesis you might find how to do it with some other kind of shading device.*

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I
don't understand is if the OpenStudio simulation of Radiance andEnergyPlus calculates the new solar heat gain (of the CFS) using Radiance
or EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If OpenStudiodoes this already, maybe I'm just missing it and someone can point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain < >>> [email protected]> wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing
I heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate
Solar Heat Gain by itself, and the luminaire power will be defined
from a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis,
working with integrated Thermal and Lighting simulations of spaces with
controlled Luminaires and Complex Fenestration Systems. I used Radiance
and EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my
thesis, or related information.

I wanted to contribute to OpenStudio, but my programming skills and
lack of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a
basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have
determined
that the three-phase method is probably going to be our best option.
We're
looking to model the effects the dynamic glazing system would have on
the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available
to do
this and found "Challenges of Integrated Daylight and Electrical
Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by
Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one
of the
most integrated and streamline options available for coupled daylight
and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the
solar heat
gain? The daylight is well studied and discussed, but I haven't been
able to
find out whether this method will discount the solar heat gain
through the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors
for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

_______________________________________________
[email protected]

Hey Justin, welcome, and sorry about the list subscription snafu!

So, let’s see. German is right, in its current form. OpenStudio uses Radiance to do an annual daylight simulation, and runs a tool called mkschedule.rb to generate electric lighting load schedules based on the occupancy schedules and daylighting controls (and setpoints) in the OS model, and the daylight availability as calculated by Radiance. These schedules are then put back onto the OpenStudio model which is then passed to EnergyPlus, which does all the solar thermal stuff on its own. Somewhat convoluted and unfortunately linear, but all managed automatically for you by the OpenStudio application.

We (and others) are using the OpenStudio API to write little helper programs to link things a little bit better, so that BSDFs can be used to model CFS, dynamically, and some of these efforts are currently being integrated in to the OpenStudio application as we speak. In the very near future, a user will be able to assign generic shades to any window or series of windows in your OpenStudio model, and select from a number of the shade control algorithms available in EnergyPlus; OpenStudio will then perform a so-called dynamic daylight simulation of the model both in Radiance (for the daylighting) and E+ (for the thermal); all the shading controls are automatically applied to both the Radiance and EnergyPlus models.

Initial support for this will be rolled out in the next month or so, and will use generic BSDFs that we will either include in OpenStudio or make available via the Building Component Library. Down the road, we will allow the user to specify arbitrary BSDFs and apply them to both the Radiance and EnergyPlus models.

- Rob

···

From: Justin Shultz <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Date: Tuesday, March 11, 2014 at 1:06 PM
To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

I've heard some things about Radiance solar heat gain calculates but haven't found any papers on how to integrate it within a whole-building simulation yet, I'll keep looking. If anyone knows of a source it would be extremely helpful.

EnergyPlus does have a nicely integrated venetian blind module, but unfortunately that doesn't exactly represent the system we're attempting to model. My project is similar but a bit more complicated in practice, although it does also block direct beam, I'll need to think if this is representative. We were imagining, creating a defined number of geometries (representative of dynamic states), create the BSDF for each, and then chose between them for various states of the annual daylight simulation.Following the three-phase method, with the integration of results in a whole-building simulation.

From your suggestions, it appears as though the best solution to calculate the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to calculate the solar heat gain and then use Radiance (with OpenStudio) for the Daylight and Lighting Load simulations. Though I'm guessing that EnergyPlus cannot handle dynamic BSDFs for various CFS configurations without some form of co-simulation. I'll have to read more into the methods EnergyPlus uses to calculate the solar heat gain from a BSDF and determine if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced methods for integrating Radiance daylight and heat gain into whole-building simulation from dynamic fenestration systems? Maybe I'm looking at the problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your SketchUp plug-in video earlier, very cool stuff.

Sincerely,
Justin

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain <[email protected]<mailto:[email protected]>> wrote:
Although I have heard some things about calculating solar heat gains with Radiance, I do not think OpenStudio does that... I did not do that, at least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and other shading devices, and also inserting the BSDF of a CFS, and it will calculate the solar heat gains. My understanding is that the BSDF-based modelling of a CFS will be accurate enough for performing the calculation... maybe Radiance would be better for more complex handling geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow you to choose a "block beam radiation" algorithm. I guess that, from that, you can report the VB position, and perform the lighting simulation in Radiance, and choose the artificial lighting power for the luminaires, and write them down in a schedule. Finally, you can go back to EnergyPlus, and use the lighting power, and use it to control the internal gains caused by the artificial lighting. THIS WOULD BE VALID FOR THIS CASE. In my thesis you might find how to do it with some other kind of shading device.

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]<mailto:[email protected]>>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the daylight contributions and the mkschedule.rb code. The part that I don't understand is if the OpenStudio simulation of Radiance and EnergyPlus calculates the new solar heat gain (of the CFS) using Radiance or EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the sun's altitude. The intercepted solar irradiance will block some direct sunlight and solar heat gain. The part I'm unclear about is how to implement (if it's not already) the interception of solar heat gain from directly entering the thermal zone modeled in EnergyPlus. If OpenStudio does this already, maybe I'm just missing it and someone can point me in the right direction. If it doesn't, is there a tutorial that goes over Radiance daylight and solar heat gain simulations and how they plug into EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in understanding how to apply thermal and daylight simulations to an EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain <[email protected]<mailto:[email protected]>> wrote:
Justin,

What do you mean with "transforms the solar heat gain"? The last thing I heard is that OpenStudio uses Radiance to calculate the Daylight contribution, and choose the Artificial Lighting power in each zone, using a script called MKSCHEDULE. EnergyPlus, then, will have to calculate Solar Heat Gain by itself, and the luminaire power will be defined from a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working with integrated Thermal and Lighting simulations of spaces with controlled Luminaires and Complex Fenestration Systems. I used Radiance and EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my thesis, or related information.

I wanted to contribute to OpenStudio, but my programming skills and lack of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]<mailto:[email protected]>>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic
question. I have used EnergyPlus for many basic projects, but my most recent
one is studying a dynamic glazing system. My partner and I have determined
that the three-phase method is probably going to be our best option. We're
looking to model the effects the dynamic glazing system would have on the
electrical lighting loads, as well as, the solar heat gain into the building
zone.

I've been reviewing the tools and methods at are currently available to do
this and found "Challenges of Integrated Daylight and Electrical Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one of the
most integrated and streamline options available for coupled daylight and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar heat
gain? The daylight is well studied and discussed, but I haven't been able to
find out whether this method will discount the solar heat gain through the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors for the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]<mailto:[email protected]>

_______________________________________________
[email protected]<mailto:[email protected]>

_______________________________________________
[email protected]<mailto:[email protected]>

_______________________________________________
[email protected]<mailto:[email protected]>

Thank you for the response everyone, I appreciate your time and efforts.
Sorry to ask such a non-straightforward question.

Hello Denis,

Diva4Rhino is actually a tool I've used for solar analysis in the past.
It's a really cool tool, especially since I've seen a lot of grasshopper
use in architecture practice lately. Unfortunately, the radiation maps are
not what we're looking for because we're trying to apply the result to the
interior heat gain of the building. I believe Diva has some functionality
for determining the solar heat gain to the interior, because I remember
using in the past, but for my current project I don't believe its robust
enough.

Thank you, I'll look into ESP-r and see if it's something that can apply.

···

----------------------------------------------------------

Hello Rob,

No problem at all, I landed on the page from a google search and didn't
notice the subscribe button from the radiance page. Andrew was very helpful.

simulation, makes sense to me. It's really awesome that you made those
calculations so streamline. I do whole building simulation in an
architecture graduate program and I can already see how it would be applied
in many design applications. Though, I'm a bit confused how the solar heat
gain is effected from the OpenStudio model, with Radiance turned on.

How does the coupled Radiance and EnergyPlus method impact the solar heat
gain calculations in EnergyPlus (if at all)? In other words, if two
identical buildings were modeled, one with a CFS and Radiance and one
without, would the CFS OpenStudio model have a reduced solar heat gain? Is
the BSDF applied somewhere in the EnergyPlus model to determine new solar
heat gain values or through Radiance? If so, maybe you can elaborate on how
it's applied. Is the reduced solar heat gain due to the modules in
EnergyPlus or a data flow between Radiance and EnergyPlus?

You guys are doing awesome stuff at NREL with OpenStudio. I look forward to
seeing where it goes in the future. Whole building simulation has been my
research interest in my PhD. Through my research, I hope to gain an
advanced understanding of what's going in whole building simulation and
contribute to the field someday.

Sorry if my questions are a bit confusing. I tried asking the same question
in a couple different ways in the hope that one of them is clear.

Thank you,
Justin Shultz
PhD Student

On Tue, Mar 11, 2014 at 4:14 PM, Guglielmetti, Robert < [email protected]> wrote:

Hey Justin, welcome, and sorry about the list subscription snafu!

So, let's see. German is right, in its current form. OpenStudio uses
Radiance to do an annual daylight simulation, and runs a tool called
mkschedule.rb to generate electric lighting load schedules based on the
occupancy schedules and daylighting controls (and setpoints) in the OS
model, and the daylight availability as calculated by Radiance. These
schedules are then put back onto the OpenStudio model which is then passed
to EnergyPlus, which does all the solar thermal stuff on its own. Somewhat
convoluted and unfortunately linear, but all managed automatically for you
by the OpenStudio application.

We (and others) are using the OpenStudio API to write little helper
programs to link things a little bit better, so that BSDFs can be used to
model CFS, dynamically, and some of these efforts are currently being
integrated in to the OpenStudio application as we speak. In the very near
future, a user will be able to assign generic shades to any window or
series of windows in your OpenStudio model, and select from a number of the
shade control algorithms available in EnergyPlus; OpenStudio will then
perform a so-called dynamic daylight simulation of the model both in
Radiance (for the daylighting) and E+ (for the thermal); all the shading
controls are automatically applied to both the Radiance and EnergyPlus
models.

Initial support for this will be rolled out in the next month or so, and
will use generic BSDFs that we will either include in OpenStudio or make
available via the Building Component Library. Down the road, we will allow
the user to specify arbitrary BSDFs and apply them to both the Radiance and
EnergyPlus models.

- Rob

From: Justin Shultz <[email protected]<mailto:[email protected]>>
[email protected]>" <
[email protected]<mailto:
[email protected]>>
Date: Tuesday, March 11, 2014 at 1:06 PM
To: "[email protected]<mailto:
[email protected]>" <
[email protected]<mailto:
[email protected]>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC)
Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

haven't found any papers on how to integrate it within a whole-building
simulation yet, I'll keep looking. If anyone knows of a source it would be

EnergyPlus does have a nicely integrated venetian blind module, but
unfortunately that doesn't exactly represent the system we're attempting to
model. My project is similar but a bit more complicated in practice,
although it does also block direct beam, I'll need to think if this is
representative. We were imagining, creating a defined number of geometries
(representative of dynamic states), create the BSDF for each, and then
chose between them for various states of the annual daylight
simulation.Following the three-phase method, with the integration of
results in a whole-building simulation.

From your suggestions, it appears as though the best solution to calculate
the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to
calculate the solar heat gain and then use Radiance (with OpenStudio) for
the Daylight and Lighting Load simulations. Though I'm guessing that
EnergyPlus cannot handle dynamic BSDFs for various CFS configurations
without some form of co-simulation. I'll have to read more into the methods
EnergyPlus uses to calculate the solar heat gain from a BSDF and determine
if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced
methods for integrating Radiance daylight and heat gain into whole-building
simulation from dynamic fenestration systems? Maybe I'm looking at the
problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your
SketchUp plug-in video earlier, very cool stuff.

Sincerely,
Justin

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain < > [email protected]<mailto:[email protected]>> wrote:
Although I have heard some things about calculating solar heat gains with
Radiance, I do not think OpenStudio does that... I did not do that, at
least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and
other shading devices, and also inserting the BSDF of a CFS, and it will
calculate the solar heat gains. My understanding is that the BSDF-based
modelling of a CFS will be accurate enough for performing the
calculation... maybe Radiance would be better for more complex handling
geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow you
to choose a "block beam radiation" algorithm. I guess that, from that, you
can report the VB position, and perform the lighting simulation in
Radiance, and choose the artificial lighting power for the luminaires, and
write them down in a schedule. Finally, you can go back to EnergyPlus, and
use the lighting power, and use it to control the internal gains caused by
the artificial lighting. THIS WOULD BE VALID FOR THIS CASE. In my thesis
you might find how to do it with some other kind of shading device.

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]<mailto:
[email protected]>>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the
daylight contributions and the mkschedule.rb code. The part that I don't
understand is if the OpenStudio simulation of Radiance and EnergyPlus
calculates the new solar heat gain (of the CFS) using Radiance or
EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the
sun's altitude. The intercepted solar irradiance will block some direct
sunlight and solar heat gain. The part I'm unclear about is how to
implement (if it's not already) the interception of solar heat gain from
directly entering the thermal zone modeled in EnergyPlus. If OpenStudio
does this already, maybe I'm just missing it and someone can point me in
the right direction. If it doesn't, is there a tutorial that goes over
Radiance daylight and solar heat gain simulations and how they plug into
EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in
understanding how to apply thermal and daylight simulations to an
EnergyPlus simulation.

Thank you,
Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain < > [email protected]<mailto:[email protected]>> wrote:
Justin,

What do you mean with "transforms the solar heat gain"? The last thing I
heard is that OpenStudio uses Radiance to calculate the Daylight
contribution, and choose the Artificial Lighting power in each zone, using
a script called MKSCHEDULE. EnergyPlus, then, will have to calculate Solar
Heat Gain by itself, and the luminaire power will be defined from a
Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working
with integrated Thermal and Lighting simulations of spaces with controlled
Luminaires and Complex Fenestration Systems. I used Radiance and
EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my thesis,
or related information.

I wanted to contribute to OpenStudio, but my programming skills and lack
of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]<mailto:
[email protected]>>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic
question. I have used EnergyPlus for many basic projects, but my most
recent
one is studying a dynamic glazing system. My partner and I have determined
that the three-phase method is probably going to be our best option. We're
looking to model the effects the dynamic glazing system would have on the
electrical lighting loads, as well as, the solar heat gain into the
building
zone.

I've been reviewing the tools and methods at are currently available to do
this and found "Challenges of Integrated Daylight and Electrical Lighting
Simulation Methods in a Whole-Building Energy Simulation Context" by Rob
Guglielmetti to be tremendously helpful. OpenStudio appears to be one of
the
most integrated and streamline options available for coupled daylight and
whole building simulation.

The question I have, that I haven't been able to find, is whether the
OpenStudio coupled Radiance and EnergyPlus method transforms the solar heat
gain? The daylight is well studied and discussed, but I haven't been able
to
find out whether this method will discount the solar heat gain through the
fenestration systems.

Additional side question: When running genBSDF is there a command or
something material property that needs to be added to get the factors for
the
SHGC? We have only been able to get the daylight coefficients.

Justin Shultz
PhD Student

_______________________________________________
[email protected]<mailto:
[email protected]>

_______________________________________________
[email protected]<mailto:
[email protected]>

_______________________________________________
[email protected]<mailto:
[email protected]>

_______________________________________________
[email protected]<mailto:
[email protected]>

_______________________________________________
[email protected]

Hello Justin and OpenStudio and Radiance users and developers,

What an interesting discussion. By now I'm working in my PhD and this question -how I could integrate illuminances with solar heat gains through windows- has been one of the hardest things.

Firstly, because when I simulated my models there weren't some tools like DIVA or OpenStudio, or the were starting, so I decided to duplicate the simulations: every model has been calculated with DAYSIM for getting the illuminances for each time step throughout a year, and has been calcualted with DesignBuilder (EnergyPlus) for getting the solar heat gains for the same time step and period. I think you can do as I did with OpenStudio and Radiance.

Secondly, how to integrate both results. Illuminances are given for every sensor and Solar heat gains are given for the whole thermal zone; one is punctual and other is volumetric, so I decided to treat every measure in order to find a common place to be compared and integrated.

So I think the question is not if the programs are coupled or could be coupled (anyway, every engine is design to calculate different aspects so soon or later they will work "together"), the key question is to obtain measures for the same climatic conditions, period, time step (these three are conditions are now able to achieve) and, very important, dimension.

Hope to be able soon to show you how I treated those measures.

Best,
Paula Esquivias

···

Date: Tue, 11 Mar 2014 17:19:57 -0400
From: [email protected]
To: [email protected]
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Thank you for the response everyone, I appreciate your time and efforts. Sorry to ask such a non-straightforward question.
Hello Denis,
Diva4Rhino is actually a tool I've used for solar analysis in the past. It's a really cool tool, especially since I've seen a lot of grasshopper use in architecture practice lately. Unfortunately, the radiation maps are not what we're looking for because we're trying to apply the result to the interior heat gain of the building. I believe Diva has some functionality for determining the solar heat gain to the interior, because I remember using in the past, but for my current project I don't believe its robust enough.

Thank you, I'll look into ESP-r and see if it's something that can apply.
----------------------------------------------------------
Hello Rob,

No problem at all, I landed on the page from a google search and didn't notice the subscribe button from the radiance page. Andrew was very helpful.
The EnergyPlus lighting load schedule, generated from the Radiance daylight simulation, makes sense to me. It's really awesome that you made those calculations so streamline. I do whole building simulation in an architecture graduate program and I can already see how it would be applied in many design applications. Though, I'm a bit confused how the solar heat gain is effected from the OpenStudio model, with Radiance turned on.

How does the coupled Radiance and EnergyPlus method impact the solar heat gain calculations in EnergyPlus (if at all)? In other words, if two identical buildings were modeled, one with a CFS and Radiance and one without, would the CFS OpenStudio model have a reduced solar heat gain? Is the BSDF applied somewhere in the EnergyPlus model to determine new solar heat gain values or through Radiance? If so, maybe you can elaborate on how it's applied. Is the reduced solar heat gain due to the modules in EnergyPlus or a data flow between Radiance and EnergyPlus?

You guys are doing awesome stuff at NREL with OpenStudio. I look forward to seeing where it goes in the future. Whole building simulation has been my research interest in my PhD. Through my research, I hope to gain an advanced understanding of what's going in whole building simulation and contribute to the field someday.

Sorry if my questions are a bit confusing. I tried asking the same question in a couple different ways in the hope that one of them is clear.
Thank you,Justin Shultz
PhD Student

On Tue, Mar 11, 2014 at 4:14 PM, Guglielmetti, Robert <[email protected]> wrote:

Hey Justin, welcome, and sorry about the list subscription snafu!

So, let’s see. German is right, in its current form. OpenStudio uses Radiance to do an annual daylight simulation, and runs a tool called mkschedule.rb to generate electric lighting load schedules based on the occupancy schedules and daylighting controls (and setpoints) in the OS model, and the daylight availability as calculated by Radiance. These schedules are then put back onto the OpenStudio model which is then passed to EnergyPlus, which does all the solar thermal stuff on its own. Somewhat convoluted and unfortunately linear, but all managed automatically for you by the OpenStudio application.

We (and others) are using the OpenStudio API to write little helper programs to link things a little bit better, so that BSDFs can be used to model CFS, dynamically, and some of these efforts are currently being integrated in to the OpenStudio application as we speak. In the very near future, a user will be able to assign generic shades to any window or series of windows in your OpenStudio model, and select from a number of the shade control algorithms available in EnergyPlus; OpenStudio will then perform a so-called dynamic daylight simulation of the model both in Radiance (for the daylighting) and E+ (for the thermal); all the shading controls are automatically applied to both the Radiance and EnergyPlus models.

Initial support for this will be rolled out in the next month or so, and will use generic BSDFs that we will either include in OpenStudio or make available via the Building Component Library. Down the road, we will allow the user to specify arbitrary BSDFs and apply them to both the Radiance and EnergyPlus models.

- Rob

From: Justin Shultz <[email protected]<mailto:[email protected]>>

Date: Tuesday, March 11, 2014 at 1:06 PM

Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

I've heard some things about Radiance solar heat gain calculates but haven't found any papers on how to integrate it within a whole-building simulation yet, I'll keep looking. If anyone knows of a source it would be extremely helpful.

EnergyPlus does have a nicely integrated venetian blind module, but unfortunately that doesn't exactly represent the system we're attempting to model. My project is similar but a bit more complicated in practice, although it does also block direct beam, I'll need to think if this is representative. We were imagining, creating a defined number of geometries (representative of dynamic states), create the BSDF for each, and then chose between them for various states of the annual daylight simulation.Following the three-phase method, with the integration of results in a whole-building simulation.

From your suggestions, it appears as though the best solution to calculate the solar heat gain would be to integrate a BSDF in EnergyPlus. Use E+ to calculate the solar heat gain and then use Radiance (with OpenStudio) for the Daylight and Lighting Load simulations. Though I'm guessing that EnergyPlus cannot handle dynamic BSDFs for various CFS configurations without some form of co-simulation. I'll have to read more into the methods EnergyPlus uses to calculate the solar heat gain from a BSDF and determine if that meets my criteria.

Does anyone know of any articles or publications that discuss advanced methods for integrating Radiance daylight and heat gain into whole-building simulation from dynamic fenestration systems? Maybe I'm looking at the problem from the wrong perspective.

Thank you German, I look forward to receiving your thesis. I watched your SketchUp plug-in video earlier, very cool stuff.

Sincerely,

Justin

On Tue, Mar 11, 2014 at 2:33 PM, Germán Molina Larrain <[email protected]<mailto:[email protected]>> wrote:

Although I have heard some things about calculating solar heat gains with Radiance, I do not think OpenStudio does that... I did not do that, at least.

EnergyPlus allows modelling simple glazing, Venetian Blinds, shades and other shading devices, and also inserting the BSDF of a CFS, and it will calculate the solar heat gains. My understanding is that the BSDF-based modelling of a CFS will be accurate enough for performing the calculation... maybe Radiance would be better for more complex handling geometries and materials though.

I also understand that VenetianBlinds, as defined in EnergyPlus, allow you to choose a "block beam radiation" algorithm. I guess that, from that, you can report the VB position, and perform the lighting simulation in Radiance, and choose the artificial lighting power for the luminaires, and write them down in a schedule. Finally, you can go back to EnergyPlus, and use the lighting power, and use it to control the internal gains caused by the artificial lighting. THIS WOULD BE VALID FOR THIS CASE. In my thesis you might find how to do it with some other kind of shading device.

I will attach my Thesis directly to you later.

Bye!

Germán

2014-03-11 15:11 GMT-03:00 Justin Shultz <[email protected]<mailto:[email protected]>>:

Hello German,

Thank you for the quick reply. Yeah, that's my understanding of the daylight contributions and the mkschedule.rb code. The part that I don't understand is if the OpenStudio simulation of Radiance and EnergyPlus calculates the new solar heat gain (of the CFS) using Radiance or EnergyPlus, if at all.

Let's use a dynamic venitican blind as an example, ones that track the sun's altitude. The intercepted solar irradiance will block some direct sunlight and solar heat gain. The part I'm unclear about is how to implement (if it's not already) the interception of solar heat gain from directly entering the thermal zone modeled in EnergyPlus. If OpenStudio does this already, maybe I'm just missing it and someone can point me in the right direction. If it doesn't, is there a tutorial that goes over Radiance daylight and solar heat gain simulations and how they plug into EnergyPlus. Also, the limitations of using said method.

If you don't mind sharing, I think your thesis would be very helpful in understanding how to apply thermal and daylight simulations to an EnergyPlus simulation.

Thank you,

Justin

On Tue, Mar 11, 2014 at 1:57 PM, Germán Molina Larrain <[email protected]<mailto:[email protected]>> wrote:

Justin,

What do you mean with "transforms the solar heat gain"? The last thing I heard is that OpenStudio uses Radiance to calculate the Daylight contribution, and choose the Artificial Lighting power in each zone, using a script called MKSCHEDULE. EnergyPlus, then, will have to calculate Solar Heat Gain by itself, and the luminaire power will be defined from a Schedule created with the MKSCHEDULE script.

On the other hand, I worked on that topic during my M.Sc. Thesis, working with integrated Thermal and Lighting simulations of spaces with controlled Luminaires and Complex Fenestration Systems. I used Radiance and EnergyPlus, but no OpenStudio. You (and anyone) can ask me for my thesis, or related information.

I wanted to contribute to OpenStudio, but my programming skills and lack of time did not allow me.

Bye!

Germán

2014-03-11 14:42 GMT-03:00 Justin Shultz <[email protected]<mailto:[email protected]>>:

Hello Radiance and OpenStudio users and developers,

I'm new to the radiance and daylight simulation. Sorry if this is a basic

question. I have used EnergyPlus for many basic projects, but my most recent

one is studying a dynamic glazing system. My partner and I have determined

that the three-phase method is probably going to be our best option. We're

looking to model the effects the dynamic glazing system would have on the

electrical lighting loads, as well as, the solar heat gain into the building

zone.

I've been reviewing the tools and methods at are currently available to do

this and found "Challenges of Integrated Daylight and Electrical Lighting

Simulation Methods in a Whole-Building Energy Simulation Context" by Rob

Guglielmetti to be tremendously helpful. OpenStudio appears to be one of the

most integrated and streamline options available for coupled daylight and

whole building simulation.

The question I have, that I haven't been able to find, is whether the

OpenStudio coupled Radiance and EnergyPlus method transforms the solar heat

gain? The daylight is well studied and discussed, but I haven't been able to

find out whether this method will discount the solar heat gain through the

fenestration systems.

Additional side question: When running genBSDF is there a command or

something material property that needs to be added to get the factors for the

SHGC? We have only been able to get the daylight coefficients.

Justin Shultz

PhD Student

_______________________________________________

_______________________________________________

_______________________________________________

_______________________________________________

_______________________________________________

[email protected]

_______________________________________________
[email protected]

Hi Justin, a couple of answers below, inline (prefixed with “***RPG:”)

- Rob

···

From: Justin Shultz <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Date: Tuesday, March 11, 2014 at 3:19 PM
To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Thank you for the response everyone, I appreciate your time and efforts. Sorry to ask such a non-straightforward question.

Hello Denis,

Diva4Rhino is actually a tool I've used for solar analysis in the past. It's a really cool tool, especially since I've seen a lot of grasshopper use in architecture practice lately. Unfortunately, the radiation maps are not what we're looking for because we're trying to apply the result to the interior heat gain of the building. I believe Diva has some functionality for determining the solar heat gain to the interior, because I remember using in the past, but for my current project I don't believe its robust enough.

Thank you, I'll look into ESP-r and see if it's something that can apply.

----------------------------------------------------------

Hello Rob,

No problem at all, I landed on the page from a google search and didn't notice the subscribe button from the radiance page. Andrew was very helpful.

***RPG: Yes, Andrew generally is. =8-)

The EnergyPlus lighting load schedule, generated from the Radiance daylight simulation, makes sense to me. It's really awesome that you made those calculations so streamline. I do whole building simulation in an architecture graduate program and I can already see how it would be applied in many design applications. Though, I'm a bit confused how the solar heat gain is effected from the OpenStudio model, with Radiance turned on.

How does the coupled Radiance and EnergyPlus method impact the solar heat gain calculations in EnergyPlus (if at all)? In other words, if two identical buildings were modeled, one with a CFS and Radiance and one without, would the CFS OpenStudio model have a reduced solar heat gain? Is the BSDF applied somewhere in the EnergyPlus model to determine new solar heat gain values or through Radiance? If so, maybe you can elaborate on how it's applied. Is the reduced solar heat gain due to the modules in EnergyPlus or a data flow between Radiance and EnergyPlus?

***RPG: Great question(s). We are implementing using BSDFs on the Radiance side to model shades, blinds, and diffusing glass, in a general way. All of these things can also be modeled in EnergyPlus. The plan is to upload a library of generic BSDFs describing:

1. Clear glazing (1-91% VLT)
2. Clear glazing with venetian blinds (slats preset to something aggressive, and blinds fully extended, i.e. covering the entire window)
3. Clear glazing with shadecloth material (5% openness, fully extended)
4. Diffuse glazing (1-70% VLT)

These BSDFs all correspond to various EnergyPlus Construction Assembly.Fenestration.Window elements or material properties. We also have exposed several of the EnergyPlus shade control options:

1. Always on (down)
2. Always off (up)
3. Operate by schedule (user-supplied)
4. On if high solar

The user applies shading controls to one or more windows in the OpenStudio model; at run time the OpenStudio-to-Radiance translator will map the appropriate BSDF pairs to each window group (windows sharing orientation and shading control) so that the daylight availability will be calculated by Radiance, and will be based on user-specified operable shades and control. After that, OpenStudio works like it always has during a Radiance simulation: the electric lighting schedules are computed, and passed back to the OpenStudio model, which then computes the building energy use with EnergyPlus.

In other words, it’s still a serial process, where Radiance goes first and does a daylight simulation, thus informing the electric lighting operation, which is passed to EnergyPlus for the rest of it. It’s integrated, but could hardly be called “cosimulation”. Not yet, anyway.

Hopefully this all makes sense. (?) We hope to release all of this functionality in the next couple of months.

- Rob

Thank you for the responses everyone. This has been extremely helpful.

Paula,

I look forward to reading your thesis, sounds very applicatable. I agree, I
think the method that I will need to use will be to tie a Radiance
simulation to EnergyPlus. The trick will be figuring out how to transform
the Radiance result to EnergyPlus input.

···

------

Rob,

Thank you for your thorough response. Im excited to see where OpenStudio
goes and how it get integrated into the design process. The features you
guys are integrating and streamlining will be really fun to test out in the
future. Unfortunately, I'm going to need more control over the BSDFs
selection and control. This project is also on a short(ish) deadline.

It appears as though to model a custom, dynamic CFS I am going to have to
use the radiance 3-phase simulations and manually tie the results into
EnergyPlus with a schedule and maybe (EMS for the solar heat gain). The
3-phase method seems to be the best method for this so I'm going to have to

I found "The Three-Phase Method for Simulating Complex Fenestration with
Radiance" tutorial by Andrew McNeil. It looks like a good place to start
but the disconnnect in my head is how to take the annual simulation results
and convert them to a schedule for EnergyPlus. There are a couple programs
that do this already, like DAYSIM and OpenStudio, but I haven't figured out
how to do it manually. Does anyone have any material on how to manually
convert Radiance results to an EnergyPlus schedule?

I've been reading through German Molina's thesis, which has been very
helpful so far. I was wondering if there are any tutorials (over tips) that
step someone through how to convert Radiance result to an EnergyPlus
schedule? I thought there might have been a module in Radiance that did
this but I haven't been able to find it.

Thank you for the help everyone, I really appreciate it. Sorry to keep the
chain going for so long. I hope this is benefitial to others too!
Justin Shultz
PhD Student

On Thu, Mar 13, 2014 at 12:21 AM, Guglielmetti, Robert < [email protected]> wrote:

Hi Justin, a couple of answers below, inline (prefixed with "***RPG:")

- Rob

From: Justin Shultz <[email protected]<mailto:[email protected]>>
[email protected]>" <
[email protected]<mailto:
[email protected]>>
Date: Tuesday, March 11, 2014 at 3:19 PM
To: "[email protected]<mailto:
[email protected]>" <
[email protected]<mailto:
[email protected]>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC)
Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Thank you for the response everyone, I appreciate your time and efforts.
Sorry to ask such a non-straightforward question.

Hello Denis,

Diva4Rhino is actually a tool I've used for solar analysis in the past.
It's a really cool tool, especially since I've seen a lot of grasshopper
use in architecture practice lately. Unfortunately, the radiation maps are
not what we're looking for because we're trying to apply the result to the
interior heat gain of the building. I believe Diva has some functionality
for determining the solar heat gain to the interior, because I remember
using in the past, but for my current project I don't believe its robust
enough.

Thank you, I'll look into ESP-r and see if it's something that can apply.

----------------------------------------------------------

Hello Rob,

No problem at all, I landed on the page from a google search and didn't
notice the subscribe button from the radiance page. Andrew was very helpful.

***RPG: Yes, Andrew generally is. =8-)

daylight simulation, makes sense to me. It's really awesome that you made
those calculations so streamline. I do whole building simulation in an
architecture graduate program and I can already see how it would be applied
in many design applications. Though, I'm a bit confused how the solar heat
gain is effected from the OpenStudio model, with Radiance turned on.

How does the coupled Radiance and EnergyPlus method impact the solar heat
gain calculations in EnergyPlus (if at all)? In other words, if two
identical buildings were modeled, one with a CFS and Radiance and one
without, would the CFS OpenStudio model have a reduced solar heat gain? Is
the BSDF applied somewhere in the EnergyPlus model to determine new solar
heat gain values or through Radiance? If so, maybe you can elaborate on how
it's applied. Is the reduced solar heat gain due to the modules in
EnergyPlus or a data flow between Radiance and EnergyPlus?

***RPG: Great question(s). We are implementing using BSDFs on the Radiance
side to model shades, blinds, and diffusing glass, in a general way. All of
these things can also be modeled in EnergyPlus. The plan is to upload a
library of generic BSDFs describing:

1. Clear glazing (1-91% VLT)
2. Clear glazing with venetian blinds (slats preset to something
aggressive, and blinds fully extended, i.e. covering the entire window)
3. Clear glazing with shadecloth material (5% openness, fully extended)
4. Diffuse glazing (1-70% VLT)

These BSDFs all correspond to various EnergyPlus Construction
Assembly.Fenestration.Window elements or material properties. We also have
exposed several of the EnergyPlus shade control options:

1. Always on (down)
2. Always off (up)
3. Operate by schedule (user-supplied)
4. On if high solar

The user applies shading controls to one or more windows in the OpenStudio
model; at run time the OpenStudio-to-Radiance translator will map the
appropriate BSDF pairs to each window group (windows sharing orientation
and shading control) so that the daylight availability will be calculated
control. After that, OpenStudio works like it always has during a Radiance
simulation: the electric lighting schedules are computed, and passed back
to the OpenStudio model, which then computes the building energy use with
EnergyPlus.

In other words, it's still a serial process, where Radiance goes first and
does a daylight simulation, thus informing the electric lighting operation,
which is passed to EnergyPlus for the rest of it. It's integrated, but
could hardly be called "cosimulation". Not yet, anyway.

Hopefully this all makes sense. (?) We hope to release all of this
functionality in the next couple of months.

- Rob

_______________________________________________
[email protected]

Depending on what you are using CFS/BSDFs for, you could do most everything you want with the existing OpenStudio stuff, and getting the rest of it working would be a lot easier by leveraging the OpenStudio SDK. At least, you wouldn't be starting from scratch. I apologize for the dearth of good documentation on this.

As German mentioned, the OpenStudio utility script "MkSchedule.rb" basically illustrates how to create a lighting schedule for OpenStudio (and in turn, for EnergyPlus), and how to replace an existing OpenStudio lighting load schedule, and disable the EnergyPlus daylighting calculations. If the dynamic CFS you have is only two state, and the controls are rotationally invariant, you can do what you need to do now with OpenStudio. If your model has complex spaces that borrow light from other thermal zones, or have orientation-dependent controls operation, then our stuff is a couple of months away from supporting that. But it's possible that your use case would be helpful for us in our debugging, so we should probably talk offline. Interested?

- Rob

···

From: Justin Shultz <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Date: Thursday, March 13, 2014 at 12:08 PM
To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Thank you for the responses everyone. This has been extremely helpful.

Paula,

I look forward to reading your thesis, sounds very applicatable. I agree, I think the method that I will need to use will be to tie a Radiance simulation to EnergyPlus. The trick will be figuring out how to transform the Radiance result to EnergyPlus input.

------

Rob,

Thank you for your thorough response. Im excited to see where OpenStudio goes and how it get integrated into the design process. The features you guys are integrating and streamlining will be really fun to test out in the future. Unfortunately, I'm going to need more control over the BSDFs selection and control. This project is also on a short(ish) deadline.

It appears as though to model a custom, dynamic CFS I am going to have to use the radiance 3-phase simulations and manually tie the results into EnergyPlus with a schedule and maybe (EMS for the solar heat gain). The 3-phase method seems to be the best method for this so I'm going to have to read up on that process.

I found "The Three-Phase Method for Simulating Complex Fenestration with Radiance" tutorial by Andrew McNeil. It looks like a good place to start but the disconnnect in my head is how to take the annual simulation results and convert them to a schedule for EnergyPlus. There are a couple programs that do this already, like DAYSIM and OpenStudio, but I haven't figured out how to do it manually. Does anyone have any material on how to manually convert Radiance results to an EnergyPlus schedule?

I've been reading through German Molina's thesis, which has been very helpful so far. I was wondering if there are any tutorials (over tips) that step someone through how to convert Radiance result to an EnergyPlus schedule? I thought there might have been a module in Radiance that did this but I haven't been able to find it.

Thank you for the help everyone, I really appreciate it. Sorry to keep the chain going for so long. I hope this is benefitial to others too!
Justin Shultz
PhD Student

On Thu, Mar 13, 2014 at 12:21 AM, Guglielmetti, Robert <[email protected]<mailto:[email protected]>> wrote:
Hi Justin, a couple of answers below, inline (prefixed with “***RPG:”)

- Rob

From: Justin Shultz <[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>>
Reply-To: "[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>" <[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>>
Date: Tuesday, March 11, 2014 at 3:19 PM
To: "[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>" <[email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>>
Subject: Re: [Radiance-openstudio] Solar Heat Gain Coefficient (SHGC) Calculations in OpenStudio's Coupled Radiance and EnergyPlus Simulations

Thank you for the response everyone, I appreciate your time and efforts. Sorry to ask such a non-straightforward question.

Hello Denis,

Diva4Rhino is actually a tool I've used for solar analysis in the past. It's a really cool tool, especially since I've seen a lot of grasshopper use in architecture practice lately. Unfortunately, the radiation maps are not what we're looking for because we're trying to apply the result to the interior heat gain of the building. I believe Diva has some functionality for determining the solar heat gain to the interior, because I remember using in the past, but for my current project I don't believe its robust enough.

Thank you, I'll look into ESP-r and see if it's something that can apply.

----------------------------------------------------------

Hello Rob,

No problem at all, I landed on the page from a google search and didn't notice the subscribe button from the radiance page. Andrew was very helpful.

***RPG: Yes, Andrew generally is. =8-)

The EnergyPlus lighting load schedule, generated from the Radiance daylight simulation, makes sense to me. It's really awesome that you made those calculations so streamline. I do whole building simulation in an architecture graduate program and I can already see how it would be applied in many design applications. Though, I'm a bit confused how the solar heat gain is effected from the OpenStudio model, with Radiance turned on.

How does the coupled Radiance and EnergyPlus method impact the solar heat gain calculations in EnergyPlus (if at all)? In other words, if two identical buildings were modeled, one with a CFS and Radiance and one without, would the CFS OpenStudio model have a reduced solar heat gain? Is the BSDF applied somewhere in the EnergyPlus model to determine new solar heat gain values or through Radiance? If so, maybe you can elaborate on how it's applied. Is the reduced solar heat gain due to the modules in EnergyPlus or a data flow between Radiance and EnergyPlus?

***RPG: Great question(s). We are implementing using BSDFs on the Radiance side to model shades, blinds, and diffusing glass, in a general way. All of these things can also be modeled in EnergyPlus. The plan is to upload a library of generic BSDFs describing:

1. Clear glazing (1-91% VLT)
2. Clear glazing with venetian blinds (slats preset to something aggressive, and blinds fully extended, i.e. covering the entire window)
3. Clear glazing with shadecloth material (5% openness, fully extended)
4. Diffuse glazing (1-70% VLT)

These BSDFs all correspond to various EnergyPlus Construction Assembly.Fenestration.Window elements or material properties. We also have exposed several of the EnergyPlus shade control options:

1. Always on (down)
2. Always off (up)
3. Operate by schedule (user-supplied)
4. On if high solar

The user applies shading controls to one or more windows in the OpenStudio model; at run time the OpenStudio-to-Radiance translator will map the appropriate BSDF pairs to each window group (windows sharing orientation and shading control) so that the daylight availability will be calculated by Radiance, and will be based on user-specified operable shades and control. After that, OpenStudio works like it always has during a Radiance simulation: the electric lighting schedules are computed, and passed back to the OpenStudio model, which then computes the building energy use with EnergyPlus.

In other words, it’s still a serial process, where Radiance goes first and does a daylight simulation, thus informing the electric lighting operation, which is passed to EnergyPlus for the rest of it. It’s integrated, but could hardly be called “cosimulation”. Not yet, anyway.

Hopefully this all makes sense. (?) We hope to release all of this functionality in the next couple of months.

- Rob

_______________________________________________