Hello Guys,
I am modeling a building, which has?Under Floor Air Distribution (UFAD) system so, how to model this system in eQUEST software? I could not find a specific system called UFAD or?Under Floor Air Distribution to select in eQUEST software.
Further, the building has air source heat pump chiller that provide cooling in summer and heating in winter so, how we can model heat pump chiller in eQUEST software? How can we assign the same heat pump chiller for both the chilled water loop and the hot water loop?
Your help will be highly appreciated.
Regards
Ahmad
Modeling Under Floor Air Distribution (UFAD) system & Heat Pump Chiller
Jan 25, 2022
Hi Ahmad,
I have some guidance from the now-defunct Energy Design Resources that discusses how to model underfloor air distribution in eQUEST (attached ? I extracted this from a larger document to reduce the filesize); I believe this guidance is from 2006 but hopefully it still holds.
Regards,
Phil Jordan
Heatpump chillers with UFAD is the system type of the very first building energy simulation model I was ever tasked with building. Suffice to say, like most first efforts in life, that was probably the worst model I ever built? but I sure learned a lot and the challenges of modeling that system arrangement stuck with me! I haven?t been actively practicing eQuest for a while, but I think I can offer a leg up in this instance.
The EDR guidelines Phil extracted/shared will probably forever stand as a useful and appropriate resource to reference for bridging/informing approach for energy simulation in DOE2. It specifically addresses UFAD from an general/office occupancy perspective. Today, I draw this distinction only to point out if you are dealing with a data center, the best approach with modern DOE2.3 may look a little different than typical/office scenarios.
Also I?d add for context that the EDR guidelines were published chronologically before ASHRAE Standard 62.1 made some substantial advancements/developments in addressing thermal displacement ventilation. I would treat the specific guidance within that EDR document as a ?foundation? to be considered, understood, then tweaked to align with your present-day system designers? considerations, calculations, and decisions around ventilation delivery. By way of example, you can go further than suggested/prescribed by the EDR document to not only re-appropriate thermal loads, but to also create new/dedicated under-ceiling ?interstitial? plenum zones (with air walls) to better simulate a situation where you can assert buoyancy effects will be in play (as opposed to perfect mixing). I?ve taken those lessons learned and applied to simulations of other spaces without UFAD and deliberate TDV such as auditoriums, atriums, and ice hockey rinks.
That said, you are also asking about heat pump chillers. In DOE2 terms (semantics), if I?m correctly guessing the real-world equipment is 2-pipe (there?s a hydronic loop delivering either chilled or hot water to a single coil), then in DOE2.3 terms I think you might be happy with a CHILLER of TYPE = HEAT-PUMP and CONDENSER-TYPE = AIR-COOLED. I?d suggest review/reference at Volume 2: Dictionary > HVAC Components > CHILLER > Air-to-Water Heat-Pump (HEAT-PUMP, AIR-COOLED). Be mindful the number of air-side systems which can attach to a circulation loop of type 2-PIPE are limited and that probably merits separate consideration against your actual equipment.
Following is a visual example I slapped together to show what that may look like in the interface if you were to define post-wizards? I?m not certain this sort of chiller arrangement is something the wizards can set up for you however, so you may need to do what I did and create the associated loop/pump/chiller manually (after wizards):
[cid:image005.png at 01D8137C.76C00DC0]
I hope some of this is helpful!
~Nick
[cid:image001.jpg at 01D81379.7B96A370]
Nick Caton, P.E. (US), BEMP
??? ????, P.E. (US), BEMP
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
M JP
M US
Email
+81 . 070 . 3366 . 3317
+1 . 785 . 410 . 3317
nicholas.caton at se.com
?????????????
???????????????
ESS - ?????????????
[cid:image002.png at 01D81379.7B96A370]
[cid:image003.png at 01D81379.7B96A370]
[cid:image001.jpg at 01D81379.7B96A370]
Internal
Hello Nicholas,
Thanks for your detailed reply.
I have changed the chilled water loop to 2-pipe loop and changed the chiller type to "Heat Pump" as shown below but when I run the simulation I don't get in the summary report electric consumption for the space heating. I get only for the space cooling electric consumption. Could you or any body else in this forum help me out? I am stuck with this problem and can't complete my project.
I have also attached to this email the .pd2 and .inp files
Regards
Ahmad?
On Thursday, 27 January 2022, 03:05:40 pm AEDT, Nicholas CATON wrote:
Heatpump chillers with UFAD is the system type of the very first building energy simulation model I was ever tasked with building.? Suffice to say, like most first efforts in life, that was probably the worst model I ever built? but I sure learned a lot and the challenges of modeling that system arrangement stuck with me! ?I haven?t been actively practicing eQuest for a while, but I think I can offer a leg up in this instance.
?
The EDR guidelines Phil extracted/shared will probably forever stand as a useful and appropriate resource to reference for bridging/informing approach for energy simulation in DOE2.? It specifically addresses UFAD from an general/office occupancy perspective. Today, I draw this distinction only to point out if you are dealing with adata center, the best approach with modern DOE2.3 may look a little different than typical/office scenarios.
?
Also I?d add for context that the EDR guidelines were published chronologically before ASHRAE Standard 62.1 made some substantial advancements/developments in addressing thermal displacement ventilation.? I would treat the specific guidance within that EDR document as a ?foundation? to be considered, understood, then tweaked to align with your present-day system designers? considerations, calculations, and decisions around ventilation delivery.? By way of example, you can go further than suggested/prescribed by the EDR document to not only re-appropriate thermal loads, but to also create new/dedicated under-ceiling ?interstitial? plenum zones (with air walls) to better simulate a situation where you can assert buoyancy effects will be in play (as opposed to perfect mixing).? I?ve taken those lessons learned and applied to simulations of other spaces without UFAD and deliberate TDV such as auditoriums, atriums, and ice hockey rinks.
?
That said, you are also asking about heat pump chillers.? In DOE2 terms (semantics), if I?m correctly guessing the real-world equipment is 2-pipe (there?s a hydronic loop delivering either chilled or hot water to a single coil), then in DOE2.3 terms I think you might be happy with a CHILLER of TYPE = HEAT-PUMP and CONDENSER-TYPE = AIR-COOLED.? I?d suggest review/reference at Volume 2: Dictionary > HVAC Components > CHILLER > Air-to-Water Heat-Pump (HEAT-PUMP, AIR-COOLED).? ?Be mindful the number of air-side systems which can attach to a circulation loop of type 2-PIPE are limited and that probably merits separate consideration against your actual equipment.
?
Following is a visual example I slapped together to show what that may look like in the interface if you were to define post-wizards? I?m not certain this sort of chiller arrangement is something the wizards can set up for you however, so you may need to do what I did and create the associated loop/pump/chiller manually (after wizards):
?
I hope some of this is helpful!
?
~Nick
?
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Nick Caton, P.E. (US), BEMP
|
???????, P.E. (US), BEMP
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| |
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
|
M JP
M US
Email
|
+81 . 070 . 3366 . 3317
+1?? . 785 .? 410? . 3317
nicholas.caton at se.com
|
?????????????
???????????????
ESS - ?????????????
|
?
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?
Internal
Further to my email below, please find attached the .pd2 and .inp files wrote:
Regards
Ahmad
On Thursday, 27 January 2022, 05:04:39 pm AEDT, Ahmad Fraij via Equest-users
Hello Nicholas,
Thanks for your detailed reply.
I have changed the chilled water loop to 2-pipe loop and changed the chiller type to "Heat Pump" as shown below but when I run the simulation I don't get in the summary report electric consumption for the space heating. I get only for the space cooling electric consumption. Could you or any body else in this forum help me out? I am stuck with this problem and can't complete my project.
I have also attached to this email the .pd2 and .inp files
Regards
Ahmad?
On Thursday, 27 January 2022, 03:05:40 pm AEDT, Nicholas CATON wrote:
Heatpump chillers with UFAD is the system type of the very first building energy simulation model I was ever tasked with building.? Suffice to say, like most first efforts in life, that was probably the worst model I ever built? but I sure learned a lot and the challenges of modeling that system arrangement stuck with me! ?I haven?t been actively practicing eQuest for a while, but I think I can offer a leg up in this instance.
?
The EDR guidelines Phil extracted/shared will probably forever stand as a useful and appropriate resource to reference for bridging/informing approach for energy simulation in DOE2.? It specifically addresses UFAD from an general/office occupancy perspective. Today, I draw this distinction only to point out if you are dealing with adata center, the best approach with modern DOE2.3 may look a little different than typical/office scenarios.
?
Also I?d add for context that the EDR guidelines were published chronologically before ASHRAE Standard 62.1 made some substantial advancements/developments in addressing thermal displacement ventilation.? I would treat the specific guidance within that EDR document as a ?foundation? to be considered, understood, then tweaked to align with your present-day system designers? considerations, calculations, and decisions around ventilation delivery.? By way of example, you can go further than suggested/prescribed by the EDR document to not only re-appropriate thermal loads, but to also create new/dedicated under-ceiling ?interstitial? plenum zones (with air walls) to better simulate a situation where you can assert buoyancy effects will be in play (as opposed to perfect mixing).? I?ve taken those lessons learned and applied to simulations of other spaces without UFAD and deliberate TDV such as auditoriums, atriums, and ice hockey rinks.
?
That said, you are also asking about heat pump chillers.? In DOE2 terms (semantics), if I?m correctly guessing the real-world equipment is 2-pipe (there?s a hydronic loop delivering either chilled or hot water to a single coil), then in DOE2.3 terms I think you might be happy with a CHILLER of TYPE = HEAT-PUMP and CONDENSER-TYPE = AIR-COOLED.? I?d suggest review/reference at Volume 2: Dictionary > HVAC Components > CHILLER > Air-to-Water Heat-Pump (HEAT-PUMP, AIR-COOLED).? ?Be mindful the number of air-side systems which can attach to a circulation loop of type 2-PIPE are limited and that probably merits separate consideration against your actual equipment.
?
Following is a visual example I slapped together to show what that may look like in the interface if you were to define post-wizards? I?m not certain this sort of chiller arrangement is something the wizards can set up for you however, so you may need to do what I did and create the associated loop/pump/chiller manually (after wizards):
?
I hope some of this is helpful!
?
~Nick
?
|
Nick Caton, P.E. (US), BEMP
|
???????, P.E. (US), BEMP
|
| |
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
|
M JP
M US
Email
|
+81 . 070 . 3366 . 3317
+1?? . 785 .? 410? . 3317
nicholas.caton at se.com
|
?????????????
???????????????
ESS - ?????????????
|
?
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| | | | | | | |
?
?
?
?
Internal
Presuming space heating is being delivered/accomplished (unmet hours are under control)?
If you move your project to Anchorage, Alaska by reassigning the weather file, does the space cooling end-use jump up in response? If so, I?d wager all energies consumed by the heatpump chiller are being allocated to / reported under the space cooling end-use.
I?m not entirely sure what?s normal behavior to expect with the current version of eQuest/doe2, so some ?kicking of the tires? like this is probably in order unless someone has immediate familiarity to impart.
If it is the case it?s all just lumped into one end-use, I anticipate you could reasonably extract/distinguish heating vs. cooling energies by pairing your hourly chiller energy with your hourly snap temperature conditions. Please advise if you need an example.
~Nick
[cid:image001.jpg at 01D8144B.BBB16EE0]
Nick Caton, P.E. (US), BEMP
??? ????, P.E. (US), BEMP
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
M JP
M US
Email
+81 . 070 . 3366 . 3317
+1 . 785 . 410 . 3317
nicholas.caton at se.com
?????????????
???????????????
ESS - ?????????????
[cid:image002.png at 01D8144B.BBB16EE0]
[cid:image003.png at 01D8144B.BBB16EE0]
[cid:image001.jpg at 01D8144B.BBB16EE0]
Internal
Hello Nicholas, wrote:
I tried more than one weather file and it seems that there is no space heating energy is calculated by eQUEST software. I tried one run with heat pump chiller/2-pipe loop and another run with cooling only chiller/chilled water loop and I got the same energy consumption for the chiller. When I change the HVAC system from heat pump chiller to DX heat pump package unit, I get space heating energy calculated.
So do you (or anybody else in the forum) have any suggestion to solve this problem? I am attaching the .pd2 and .inp files again to this email.
Regards
Ahmad
On Friday, 28 January 2022, 03:35:46 pm AEDT, Nicholas CATON
Presuming space heating is being delivered/accomplished (unmet hours are under control)?
?
If you move your project to Anchorage, Alaska by reassigning the weather file, does the space cooling end-use jump up in response?? If so, I?d wager all energies consumed by the heatpump chiller are being allocated to / reported under the space cooling end-use.?
?
I?m not entirely sure what?s normal behavior to expect with the current version of eQuest/doe2, so some ?kicking of the tires? like this is probably in order unless someone has immediate familiarity to impart.
?
If it is the case it?s all just lumped into one end-use, I anticipate you could reasonably extract/distinguish heating vs. cooling energies by pairing your hourly chiller energy with your hourly snap temperature conditions.? Please advise if you need an example.
?
~Nick
?
|
Nick Caton, P.E. (US), BEMP
|
???????, P.E. (US), BEMP
|
| |
Senior Energy Engineer
Energy Manager, Yokota Airbase
ESS - Energy & Sustainability Services
|
M JP
M US
Email
|
+81 . 070 . 3366 . 3317
+1?? . 785 .? 410? . 3317
nicholas.caton at se.com
|
?????????????
???????????????
ESS - ?????????????
|
?
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| | | | | | | |
?
?
?
?
Internal