Frequently Asked Questions (FAQs)

Warehouses must be considered carefully. The first consideration is whether it is going to be conditioned, cooled and/or heated, or semi heated. Next is the applicable energy code. Older codes did not require the building envelope to meet the energy provisions if the warehouse didn't include mechanical equipment and was unconditioned. In ASHRAE 90.1-2010 and -2013, buildings being constructed must be assumed to be conditioned.

ASHRAE 90.1-2010/90.1-2013 Section 5.1.2.3. Spaces shall be assumed to be conditioned spaces and shall comply with the requirements for conditioned spaces at the time of construction, regardless of whether mechanical or electrical equipment is included in the building permit application or installed at that time.

ASHRAE 90.1-2010/90.1-2013 5.1.2.4. In Climate Zones 3-8, a space may be designated as either semi-heated or unconditioned only if approved by the building official.

One of the reasons for this change, is years ago shell buildings being built did not have to meet the building envelope provisions, however, the intent of these buildings is that later on the spaces would be leased out and most likely conditioned.  The expense of bringing an existing building up to code can be very costly especially if portions have to be completely rebuilt to accommodate insulation. 

So, if you have a warehouse that is strictly just a warehouse (unconditioned), confirm with the code official as to whether the building envelope must meet the energy provisions even if you are complying to an older code

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.