ResCheck output - how does Chief calculate areas?

[buck_taylor]

How does Chief calculate thermal areas that are exported?

 

I created a 21' x 21' square building, standard 2x6 walls, and a 10' finished ceiling. When I export to ResCheck I get the following areas:

 

Walls: Gross area 201 ft.

Floor: 399 ft.

Ceiling: 403 ft.

 

The window and door areas are correct.

 

This is a simple example, but I do a lot of mechanical design and energy compliance work on larger complex homes and these seemingly small errors can add up.

 

 

The expected floor area and ceiling area should be 400 sq.ft. each. There is no reason for a difference.

The expected wall surface area should be 200 sq.ft. each wall. Why the extra foot?

 

What I'm asking is what reference is Chief using when defining a space or thermal boundry?

 

For heat loss, the thermal envelope starts with the first surface you encounter, so technically it would be in the inside surface of drywall for walls and ceiling, and floor finish for the floors.

 

Edited March 20, 2022 by buck_taylor
Clarification of expectations.

[Chopsaw]

I guess you need to be more specific as to the results you are expecting.  Such as you have four walls @201 = 804  but you want the doors and windows subtracted from that ?  Everything else looks ok to me maybe. If you have a cathedral ceiling it is going to be more than the floor depending on the pitch.

[lbuttery]

there are various "official" methods - depending on the agency requesting the info

 

I have suggested for 15+ years that Chief create a schedule for the most common methods

then the user could chose the needed info

 

Lew

[buck_taylor]

Update: looks like the floor area is calculated from the surface of the sheetrock, while the ceiling is calculated from the face of the framing. The walls appear to be a combination. Got a few more configurations to try and confirm.

 

@lbuttery- yes this would be a good option to have in a preference or configuration to allow the user to select the appropriate surface. It is awkward to explain to an observer why there is a difference.