I'm attempting to model a school in eQuest and I'm having some trouble with unmet hours.
The building is located in a cold climate (Calgary, Alberta) and I've selected the "Pkgd Var Vol" system type. The problem seems to have something to do with with way that I've set up this system. In ATTN report I'm getting a warning like so:
PREHEAT/HEATING-CAPACITY in SYSTEM AHU-1
is too low to provide the requested supply temperature for
the calculated mixed air temperature using total ZONE loads
(on LS-A/B) and SYSTEM design parameters, plus outside air
conditions (on LS-C), and specified capacities & air flows.
Requested temperature is 55.00 calculated is 11.80
Check HEATING-CAPACITY, HEAT-SET-T, PRE-HEAT-T, MAX-SUPPLY-T,
DESIGN-HEAT-T, and ZONE loads for consistency.
I can eliminate the unmet hours by jacking up all of the baseboard and reheat coil capacities but this results in a completely absurd level of heating energy consumption, and it also doesn't eliminate the above error.
I've noticed that manually setting the "Hot Deck Max Leaving Temp" to 95 F seems to correct the above error message, but doesn't fix the underlying problem of the unmet hours/absurd energy consumption. I've also tried manually entering an extremely high value in the "heating capacity" field of the "Heating"/"Coil Cap/Control" menu of the system and it doesn't have any effect.
A couple of strange things I've noticed that might provide some clues as to what the problem is:
- the value listed for "heating capacity" in the SV-A report is 0 (unless I enter a Max Hot Deck Leaving Temp as described above)
- the minimum zone temperature listed in the SS-F report for the underheated zones is just ridiculous--like -253.1 F for one zone.
Any ideas or suggestions would be very, very greatly appreciated.
