heating load unmet hours

Razan Nejem

Environmental Engineer, LEED AP BD+C

LEEDuser Basic Member

38 thumbs up

October 3, 2011

in the energy modeling result using HAP, the heating load unmet hours turns out to be 2000, however it shouldn't exceed 300 hours, knowing that our system is chilled water not dx units and the Tstat throttling range =1.

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 10/03/2011 - 13:39

The older versions of HAP counted simultaneous hours, so overstating the total. The latest version fixed that issue.

Razan Nejem

Environmental Engineer, LEED AP BD+C

LEEDuser Basic Member

38 thumbs up

Tue, 10/04/2011 - 06:17

Thanks Marcus, I am using version 4.5 is there a later version?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Tue, 10/04/2011 - 12:05

I think that is the latest. Sorry I don't know HAP well enough to offer further specific suggestion. Often this issue is related to schedules, most commonly during morning warm, and allowing the fans to cycle during unoccupied periods. At least that is our experience but we use eQUEST. Check out the HAP Users forum at http://onebuilding.org/