Question about Solar Loads in eQUEST?

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Hi Vikram,

I think you could take a look the doe2 engineering manual that present the detailed information about load calculation.

http://doe2.com/download/DOE-21E/DOE-2EngineersManual2.1A.pdf

Thanks,

Rongxin

2009-02-08

rongxinyin

???? Vikram Sami
????? 2009-02-08 18:19:33
???? equest-users at lists.onebuilding.org
???
??? [Equest-users] Question about Solar Loads in eQUEST

I have a question about how eQUEST calculates solar heat gain. I have been playing around with a little test building - 50' (E-W axis)x100' (N-S axis). The glass type is 2209 from the glazing library, and Walls are R10 and roof R20 (simplified). I have the building set up with no HVAC system or lights, and a 24/7 equipment load of .25w/sf and 400sf/person occupants.

I also set up hourly reporting for the following:
space temps
Building Heating & Cooling loads
Building cooling load from solar radiation through windows (this is in the building loads option)
So far so good. The matrix below is an average temperature reading for the 21st day of each month. Needless to say, I was really surprised at the lack of diurnal variation in the temperatures.
HRJanFebMarAprMayJunJulAugSepOctNovDec
1597574949710310310695887952
2597574949610210310595887952
3587573939610210210595877952
4587573939610110210494877851
5577572939510110210494877851
6577472929510110110494877851
7577472929610110110493877750
8567474929710110110694877750
9597476949910110110794877750
106275789510010210210894887851
116475799610110310210996897852
126475809810210310310997907952
136575809810210410310998918153
146676809910210510410999928254
1567778298103105104110100938355
1668778398104105104110101948456
1769768498105105104110101948356
1868768497103105103110100928254
196675839610210510210899918153
206575819510210310210798918052
216574809410110310110797908052
226574809310110210110697907951
236474799210010110010696897951
24647479919910110010596897951

Below are the values for building solar cooling load(March 21st) , and I was surprised to see pretty high numbers way into the night. Whats going on here? What am I missing? Is the program really calculating solar heat gain at night?

Any insight would be appreciated.
March 21stBuilding Sensible Heating LoadBuilding Solar Cooling LoadBuilding Cooling Load1-8365989328732-1365991306223-19593004-25131005-30065006-31552007-328320080357751900790529326600610063286880461106725510273012066069100438130646689153414066645103475150737431252981608347614183417090939149947180910791341821907648695414200622915958721055129439662204912732469230440222388724-13103009113995 Vikram Sami, LEED AP

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