Frequently Asked Questions (FAQs)

When using the ASHRAE 90.1-2013 energy code, COMcheck needs to have two EnergyPlus weather files in this folder C:\ProgramData\COMcheck\eplus\weather. The most common reasons for a compliance simulation failure are: 

1. the files are not located at this default location
2. only one file is there instead of the two needed
3. the files are of a different size than anticipated.

The two weather files will have names and file sizes similar to these (of course the file names will reflect your building’s project location):

• USA_NJ_Newark.Intl.AP.725020_TMY3.epw (~1,619 KB)
• USA_NJ_Newark.Intl.AP.725020_TMY3.ddy (~29 KB)

What to do if you get this error:  Delete one or both weather files and attempt to run simulations again so that the weather download process gets executed again.

How it works:  If these weather files are not found at the expected location (C:\ProgramData\COMcheck\eplus\weather), COMcheck will attempt to download them. 

NOTE:  Once these weather files are downloaded they will remain on the PC at C:\ProgramData\COMcheck\eplus\weather.  Therefore, the weather download process only needs to execute one time per unique project location. Obviously for this process to work the current user must have user privileges that permit COMcheck to establish an internet connection and to download these files.