User manual

FAQ for CBECC-Res 2013

FAQS POSTED ON OCTOBER 11, 2013

1. How do I use the field Window Type?

There are two new 1-story sample files that use this field.

It works consistently only when creating new windows. Here’s an example of how to use this

feature. Add windows to the library with limited features such as U-factor and SHGC. For example,

glass block, or typical efficiencies for the brand of windows to be used on the project for single hung,

picture windows, sliding glass doors, etc., but leave all the other fields blank. As you’re creating

windows, specify the window type and it will complete the U-factor and SHGC for you.

It’s most useful function is if the window efficiencies need to be changed, you can change the library

values and all the windows that point to that name will be updated.

2. Can I get hour-by-hour energy results?

You can produce hourly export files that include all of the energy end uses in normal units along

with the TDV factors (note TDV units are TDV/Btu). This capability must be activated by modifying an

.ini file. To do this:

A. Find the CBECC-Res13.ini file in the DATA directory of your program installation (not the one in

the top level).

B. Open this file in a text editor and delete the ";" at the beginning of this line:

"ExportHourlyResults_All=1"

C. Save the file.

D. Restart CBECC-Res and run the input file.

E. Find a file in the PROJECTS directory called "Name - Prop - HourlyResults.csv" where is the input

file name. (There is also a Standard Design file if you ran Standard and proposed. And if you run

multiple orientations you will get many of these.) The contents are pretty self-explanatory.

3. Will CBECC-Res run on an Apple computer?

No, it will only operate in Windows.

4. Since I am used to seeing Specific Leakage Area (SLA) for blower door testing, can you tell me how

to convert 2.8 SLA to a CFM50 for input into the program?

SLA is leakage per square foot of Conditioned Floor Area, so I can't give you the answer without

knowing the CFA. The 2008 Residential ACM Manual equation:

So CFM50 = (SLA x CFA) / 3.819

However, the input for CBECC-Res is ACH50 (Air Changes at 50 Pa.). With an 8 foot ceiling height

ACH50 = SLA x 2 and your 2.8 SLA = 5.6 ACH50.