Hello,

I've created a model using eQuest 3.65 (DOE 2.2) build 7173 that is of a 20
storey multi-residential building located in Toronto, Ontario (Canada).
There is a basement with a elevator lobby that is an interior space (no
exterior walls).

My model keeps telling me I have underheated hours for this lobby. I'm
trying to figure out why there is a heating load and I'm stumped. I have
removed what I believe to be all potential sources of heat loss. I've
deleted the underground floor (which was R-100 anyway), I've deleted the
interior walls (just to be thorough), there is no infiltration, and I've
set the ventilation to zero. In my mind, there is no source of heat loss.
I've even added a significant (10 W/ft2) equipment load and yet there are
still underheated hours (I've even reduced my Tstat setpoint to 60F).

I've run an hourly report to help figure out the loads for both the space
("Sum of all weighted loads except infil and latent") and zone ("Load
Calc'd SPACE Sensible load at const temp (Btu/hr)"). These reports all
indicate a positive load (i.e. net heat gain) from my lights, plug loads
and occupants. However through this process I'm also questioning these
reports as the lighting, people and equipment load being reported don't
exactly align with my modeled schedules for these loads....but I've put a
pin in that.

Regardless, I have no idea how to figure out what may be resulting in net
heat loss for this zone. To be thorough, I checked the elevator lobby on
the ground level and the same thing is happening. Has anybody seen this
before...any ideas what might be causing heat loss for a zone with no
ventilation and no walls and no infiltration? It does seem to be seasonal
(i.e no underheated hours in the summer) so it has some connection to
weather file but does not correlate exactly.

If you do take the time to read this, a big thank you. If you provide the
answer, you'll for sure be on Santa's "nice" list.

Chris