Where did the underheated and undercooled hours go in DOE2.3?

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I've suddenly realized I'm not getting *any* underheated (UH) or
undercooled (UC) hours listed in my SS-R report for any of my recent
projects, all of which were done using build 7175 in DOE 2.3.

Even when I purposefully simulate conditions where underheated/undercooled
hours are occurring, they aren't being reported. I've checked hourly
temperatures (Tstat setpoints versus zone temperature) so I know there are
UH and UC hours. This is occurring with different system types (I've
checked PSZ and fan coil) and different thermostat types (two-position and
proportional) and my throttling ranges are generally default values. I'm

I never had this issue with DOE 2.2 (albeit I was always using 7173 in the
past). I work with a lot of 2-pipe fan coil systems where UH and UC hours
are in abundance.

Has anyone else noticed they are no longer getting underheated and
undercooled hours in DOE2.3?


*Chris Hadlock*, M.A.Sc., P.Eng, LEED AP BD+C
Founder & Senior Energy Consultant

201 Candlewood Cr
Waterloo, ON N2L5T3
(226) 343-5599

Chris Hadlock's picture
Joined: 2012-01-23
Reputation: 0

I often get unmet heating and/or cooling hours in Build 7175, though I get the impression that my DOE2.3 models generally have fewer unmet hours than my DOE2.2 models did, probably due to simulation engine improvements but also due to me being older and in some ways, wiser. ?
If you care to share your model files, perhaps someone will take a look.

William Bishop, PE, BEMP, BEAP, CEM, LEED AP | Pathfinder Engineers & Architects LLP
Senior Energy Engineer
[Logo, company nameDescription automatically generated] T: (585) 698-1956 www.pathfinder-ea.com
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Rochester, NY 14608

Buffalo Office: 100 Corporate Parkway, Suite 116, Amherst, NY 14226

Bill Bishop's picture
Joined: 2012-02-25
Reputation: 7

Thank you Bill and others for their response which helped provide the

I had forgotten (older but apparently not wiser) that underheated and
undercooled hours are only reported for hours when the fans are scheduled
to be ON. So even though my fans were running most hours (using "Cycle On
Any" as the Night Cycle Control), no unmet hours were being reported as my
fan schedule was modeled with an OFF fan schedule (ratio of 0 for all


On Thu, Mar 30, 2023 at 12:17?PM Bishop, Bill

Chris Hadlock's picture
Joined: 2012-01-23
Reputation: 0