Hi Thu,

This looks like a good opportunity to share some things for everyone to
consider when encountering unmet hours... I'd encourage others to read
along!

CAUTION: the files you sent include a 0kB INP file... if it isn't too
late, you should save a copy in a new location if you still have your
project open!

That said, the files you did send included a SIM report file from which
I can suggest a few things.

Scrolling through the space temperature summary (SS-O), you have some
very different distributions of binned hours between the zones... many
are floating higher (into the 85+ range) for much of the year... SS-R
suggests the problem is not isolated to any particular zone/system (I
would normally verify this in my own models using the airside summary
tab after a simulation).

A few things catch my eye:

* You have a fan schedule for at least one system with zeroes
entered through the work day... I can tell you are trying to define
"residential" and "non-residential" scheduling for different spaces
under the same project... but be very careful you aren't mis-applying
any such system & load scheduling in this sense or you'll have a lot of
cooling that will not be served because your fans are simply off. The
inverse applies for those systems whose fans are noted "off" in the
evening. A review of your night-setback inputs may worth your time as
well.

* As an extension of the first bullet: Looks like you are
trying to define a cooling setback temperature of 104 degrees using your
zone cooling schedule... check whether that really makes sense. A
~30-degree differential is going to be tough for any non-oversized
system to catch up with if the building should float far beyond the set
point.

* Another reason your systems might have trouble keeping up:
this is not necessarily "wrong," but fractional schedules for things
like plug loads and occupancy ordinarily lie in-between 0 and 100% for
an energy model. Case in point: 100% misc equipment loads and
occupancy for all occupied hours is likely exacerbating the unmet
cooling hour situation (consider these items as an internal heat load),
and may simultaneously be a reason you have zero unmet heating hours to
consider at the moment although the reports are cautioning you
extensively on the topic of heating capacities...

Not an exhaustive review, but may help you identify a few stumbling
blocks. If you wish to re-engage the list with your files in the
future, I'd advise including your weather file and ensuring your INP
file is not empty.

Best of luck!

~Nick

NICK CATON, P.E.