Design Day Temp Changes not Impacting Unconditioned Zone Temperatures

2 posts / 0 new
Last post

Hi everyone,

I am modelling a parking garage and would like to know what the impact of
different heating design day temperatures has on the temperatures on each
parking garage level. The parking garage is below ground but I have
modelled P1 with some roof space. Within the Design Day Properties, when I
change the min outdoor air temp, the temperatures in the parking garage
remain the same. See below for screenshots of the changes I have made,
which is only to DRYBULB-HIGH.

I see the dry-bulb temperature changes on the LS-A reports but when I look
at the SS-F reports, the temperatures in those unconditioned zones remain

Any help would be appreciated!

Darryl Kasun, P. Eng., LEED? AP

Darryl Kasun's picture
Joined: 2017-12-02
Reputation: 0

Hi Darryl,
The temperature of an unconditioned zone is going to float based on loads in the hourly simulation. Changing the Design Day Properties affects the system sizing as reflected in the loads reports, but doesn?t change the actual loads that are used in the hourly simulation. Unconditioned zones are not heated or cooled by systems, so system sizing should have no impact on zone temperatures. The outdoor air temperature in the hourly simulation is dictated by the weather file. The zone temperatures reported in SS-F should change if you use a different weather file, provided the space has an infiltration load or exterior surface.

William Bishop, PE, BEMP, BEAP, CEM, LEED AP
Senior Energy Engineer

[Pathfinder-EA-logo-2]T: (585) 698-1956 F: (585) 325-6005
bbishop at
[cid:image011.png at 01D3E2C0.04AE5B10]134 South Fitzhugh Street
Rochester, NY 14608 Ask me why Carbon Fee & Dividend may be right for you.

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