Very low cooling load openstudio

asked 2025-02-24 14:12:48 -0500

Andrew
11 ●2

updated 2025-02-25 10:31:36 -0500

Hello,

I am trying to model 2 625sqft apartments in a building on openstudio, with hot water baseboard heaters and through wall AC's. I am getting a reasonable load for heating loads (about 11k btuh) but the cooling load is very small, around 0.06 tons. I have thermostat schedules set at 70 for heating and 78 for cooling. I have also tried using an ideal air load with similar results. Any help or advice would be appreciated. Thanks in advance

EDIT: here is the file. Looked through the error log and did not see anything obvious to my beginner self as to what the issue would be. thanks again.

answered 2025-02-25 02:27:49 -0500

Julien Marrec

30016 ●104 ●79 http://www.effibem.com/

Hard to say without seeing your model, but go ahead and start with:

Check if you have unmet cooling hours (in eplustbl.html for eg, search for "Time setpoint not met"), as this could be an indication that the autosizing is going badly. That could be because of the what you have selected for the Summer/Winter Design Day rules for the schedules (ScheduleRuleset) that you use
Read the eplusout.err carefully and see if you get any Warning/Severe errors that might hint what the problem could be
Check your interior loads (equipment, lights, etc)
Check infiltration and ventilation loads
Check you have the right design days for your weather location
Check the window (U value and SHGC in particular).
... hopefully you found a reason.