Showing 1 - 20 of 20 results:
There are a few reasons why you may be experiencing saving issues. The most common reason is due to project version control issues.
Shared project files: If you are using the internal software sharing function, multiple people should not work simultaneously in the same shared file. In these cases, when one user saves the file, it can lead to another user’s work being overwritten and lost. Make sure you are the only person working in the file and try saving again.
Multiple browser windows: Version control issues can also happen in project files that are opened in multiple browser windows. Ensure you only have the project open in one window and try saving again.
Shared accounts: Version control issues can also happen when multiple people have access to one account. If more than one person is logged into the shared account and editing the same project file at the same time, it can cause a saving error.
If none of these is true in your case, please submit a request through the Help Desk.
There is no way to merge project files at this time.
If you are using REScheck-Web or New COMcheck-Web, we recommend using the internal sharing feature within the software to allow multiple people to enter information in the same file.
To share a project, click the icon next to the project name in the Sharing column on the Home screen under My Projects. This will open a window where you can select contacts from your Address Book with whom to share the project. You will need to add the contact you wish to share with to your Address Book, located in your Profile, before sharing. They will need to have their own account in the software to access and edit the file.
If someone shares a file with you, you will receive an email with a link to access the file, and it will also appear on the Home screen under Shared Project Requests.
Note: Please do not work in a shared project file simultaneously as this can lead to saving issues.
COMcheck does account for thermal bridging of framing members, furring, etc. (depending upon the assembly). U-factor assembly calculations are taken from ASHRAE Appendix A and ASHRAE Fundamentals. The methodology used to calculate compliance is taken from ASHRAE Appendix C. When an assembly is chosen from the dropdown in COMcheck, a U-factor is automatically displayed for that assembly (excluding fenestration). Once the user enters the proposed insulation R-value(s) for the assembly, the program recalculates the assembly and updates the U-factor to the overall U-factor for the entire assembly.
Users also have the option to choose "Other" as the assembly type. If “Other” is selected, the user will need to enter the overall calculated U-factor for the entire assembly and document those calculations for the building official.
Choose a city that is the closest and has the most similar weather. Check with the building official where the project is located to confirm whether the city selected will be acceptable or if choosing the county (in REScheck) as the designation would be more appropriate.
Where a code requires mechanical penetrations through the building envelope to be explicitly accounted for, they should be added as a separate wall or roof assembly. Assign a U-factor using an appropriate published and approved U-factor or, where provided in the code, an allowable default U-factor. COMcheck will conduct area-weighted averaging to calculate the overall U-factor of the opaque wall. In most cases, the U-factor performance of mechanical penetrations is less than prescriptively required for wall or roof U-factors, so projects may be required to make up for that in some other portion of the building envelope with better performing wall insulation, better performing windows, or more roof insulation.
According to most building energy codes, a residential building includes:
- detached one-or-two family dwellings having not more than three stories above grade plane;
- buildings that consist of three or more attached townhouse units and have not more than three stories above grade plane;
- buildings that are classified in Group R-2, R-3, or R-4 and have not more than three stories above grade plane
If you have a residential building project, you should use REScheck to show compliance with the applicable residential energy code.
A commercial building is any other building that is not considered a residential building, including residential buildings greater than three stories in height.
If you have a commercial building project, you should use COMcheck to show compliance with the applicable commercial energy code.
Exterior walls in REScheck are defined by the assembly type, gross wall area, cavity/continuous R-value (or U-factor for “Other” walls), and orientation. All exterior walls are assumed to be of regular rectangular shape with an average wall height of 9 ft., and the wall width is calculated from the gross area as input by the user.
REScheck wall materials are assumed to be plywood siding, plywood structural sheathing, foam insulation sheathing on the framing exterior and batt insulation, wood framing, and 1/2-in. gypboard on the interior. The entire wall is assumed to have structural sheathing. When continuous foam insulation is specified, 100% of the wall is assumed to be covered at the specified R-value.
The U-factor for all frame walls is based on the R-value of cavity insulation and the continuous insulation R-value (if used). If the user does not enter a continuous insulation R-value (or enters a value of 0), the software assumes a sheathing R-value of 0.83. This default value gives credit for some minimal type of sheathing material (such as plywood) under the siding.
Cavity Insulation
Insulation installed between structural members such as wood studs, metal framing, and Z-clips.
Cavity insulation is used within the wood- or metal-framed wall, while rigid continuous insulation (c.i.) is placed on the exterior side of the framing. Alternative combinations of cavity insulation and sheathings in thicker walls can be used, provided the total wall assembly has a U-factor that is less than or equal to the construction requirements. REScheck wall assemblies assume cavity insulation completely fills the cavity. Users who have unique wall assemblies where the cavity is not completely filled with insulation must account for the air space within their wall assembly calculation and should use “Other” as the wall type and enter their respective overall calculated U-factor.
Calculation in REScheck: REScheck uses nominal insulation R-values. The program does not calculate for compression. For example, if R-19 is entered as the cavity insulation R-value, it assumes the full R-19 in REScheck. Walls with insulation R-values equal to or less than R-15 are modeled in REScheck as having 2x4 studs at either 16" or 24" O.C. (on center) and cavity wall insulation R-values greater than R-15 are modeled as 2x6 studs at either 16" or 24" O.C.
Continuous Insulation
Insulation that runs continuously over structural members and is free of significant thermal bridging such as rigid foam insulation above the ceiling deck. It is installed on the interior, exterior, or is integral to any opaque surface of the building envelope.
Calculation in REScheck: The assemblies listed in REScheck already have a default value added for standard sheathing (depending on the assembly component). If no sheathing is indicated by the user, the sheathing is assumed to be plywood with an R-value of 0.83. If insulated sheathing is used, only 80% of the net wall is assumed to be covered by the insulated sheathing. The other 20% is assumed to be covered with plywood.
No, the program does not calculate for compression. REScheck uses nominal insulation R-values. For example, if R-19 is entered as the cavity insulation R-value, it assumes the full R-19 in REScheck. Walls with insulation R-values equal to or less than R-15 are modeled in REScheck as having 2x4 studs at either 16" or 24" O.C. (on center) and cavity wall insulation R-values greater than R-15 are modeled as 2x6 studs at either 16” or 24” O.C.
For more detailed information on how walls are calculated please refer to the REScheck Technical Support Document.
You can break up a variable refrigerant flow (VRF) system into two systems in New COMcheck-Web. One can be defined as the VRF outdoor compressor unit. Click Add HVAC, check “Heat Pump/VRF Condensing Unit,” then select the applicable VRF unit from the dropdown, depending on the source. This type of system requires an efficiency input and metric depending on the system’s cooling capacity. There are no fan requirements for this system since it represents the compressor unit.
The partner VRF system to specify is the zone fan unit, which is located under cooling. Click Add HVAC, click Next to get to the Cooling Equipment screen, and select "VRF Zone Fan Unit." For this system type, the capacity of individual units will generally be so small that the economizer requirement will not be enforced. The system efficiency is not specified for the fan zone unit, only fan requirements and zoning.
Note: If the VRF system is not available in the HVAC system dialog, it’s likely due to the selected energy code. Some earlier energy codes don't enforce VRF system compliance.
There are a few options for sharing a project with others in New COMcheck-Web or REScheck-Web:
- Use the internal Sharing feature. Do not work simultaneously as others in the same project file.
- On the home screen, under "My Projects," navigate to the project you want to share. Click the icon in the "Sharing" column next to that project.
- A share window will pop up with the contacts in your Address Book. Click "Share" next to the name with whom you want to share the project, then click Close. If a contact is not already in your address book, you will need to add them first in your Profile.
- When you share a project with someone, they will get an email with a link to click to open the project in their account. It will also show up in their account under “Shared Project Requests.”
- Share your log in credentials with others and allow them to edit the projects in your account. Do not work simultaneously as others in the same project file.
You could do this with your existing personal account or set up a separate account where the intent is to have a login shared by multiple people.
REScheck-Web:
On the home screen, under “My Projects,” right click on the project name you want to download. Click “Download” to download the .rxl file.
Legacy COMcheck-Web:
Open the project you want to download. On the Project screen, click the page icon with a green arrow at the top (next to the project name). This will download the .cxl file.
New COMcheck-Web:
On the home screen, under “My Projects,” click the cloud icon in the Export column next to the project you want to download. This will download the .xml file.
The key point is not the age of the building, but whether it is registered or eligible to be registered and listed as a historic building. In the following cases, historic buildings are considered exempt from provisions of the energy code (however, we recommend always confirming with the state or local jurisdiction):
- listed in the State or National Register of Historic Places;
- designated as a historic property under local or state designation law or survey;
- certified as a contributing resource with the National Register listed or locally designated historic district; or
with an opinion or certification that the property is eligible to be listed on the National or State Registers of Historic Places either individually or as a contributing building to a historic district by the State Historic Preservation Officer or the Keeper of the National Register of Historic Places.
Low-energy buildings, buildings that don’t contain conditioned space, and greenhouses may be exempt from energy code envelope requirements. See language from the 2021 IECC below and view your specific energy code for more information.
Section C402.1.1 Low-energy buildings and greenhouses – The following low-energy buildings or portions separated from the remainder of the building by a building thermal envelope complying with the code, can be exempt from the building thermal envelope provisions of Section C402:
- Those with a peak design rate of energy usage less than 3.4 Btu/h x ft2 or 1.0 watt/ft2 of floor area for space conditioning purposes
- Those that do not contain conditioned space
- Greenhouses
We also recommend that you confirm with the building official on what they suggest for your specific project.
For a warehouse, the main consideration is whether it will be conditioned, cooled and/or heated, or semiheated. In ASHRAE 90.1-2019 and -2022, buildings being constructed must be assumed to be conditioned.
In ASHRAE 90.1-2022 Section 5.1.6.3. 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.
Exception: A space may be designated as either a semiheated space or an unconditioned space only if approved by the building official.
So, if you have a warehouse that is strictly just a warehouse (unconditioned), confirm with the building official as to whether the building envelope must meet the energy provisions of your specific energy code.
COMcheck determines compliance for additions in the same manner as new construction. When entering an addition, only the new portions of the building need to be shown in the software. COMcheck will perform trade-offs between envelope assemblies when determining compliance.
COMcheck determines compliance for alterations on a component-by-component basis. When entering an alteration, only the altered portions of the building need to be shown in the software. Each envelope component is checked to verify it meets or exceeds the minimum prescriptive requirements of the selected code. No trade-offs are available for alteration projects. Therefore, a compliance percentage will not be generated, and the software will only show pass/fail.
REScheck determines compliance for additions using the component performance alternative (UA or TC) in the same manner as new construction. When entering an addition, only the new portions of the building need to be shown in the software. REScheck will perform trade-offs between envelope assemblies when determining compliance.
REScheck determines compliance for alterations on a component-by-component basis. When entering an alteration, only the altered portions of the building need to be shown in the software. Each envelope component is checked to verify it meets or exceeds the minimum prescriptive requirements of the selected code. No trade-offs are available for alteration projects. Therefore, a compliance percentage will not be generated, and the software will only show pass/fail.
The recommendation is that information for the entire building (envelope, lighting, and mechanical) be entered into one file and one compliance report be exported for the project. If different team members are entering information on different screens, you can share the file within New COMcheck-Web with each team member to open and edit in their account. See FAQ: How can a COMcheck-Web or REScheck-Web project be shared with other team members?
Envelope: If you are checking to see if the envelope section will comply, and not planning to submit the report, you can simply enter the envelope components only and run compliance. Typically, COMcheck does not require that all sections be completed in a file to perform a compliance check. However, for the 2021 IECC, you may get an error message stating that efficiency packages or energy credits must be specified before seeing the envelope compliance result. This is because the 2021 IECC requires credits be selected for the entire project. If you run into this issue, contact the Help Desk for assistance.
Lighting: Enter lighting information in the Interior Lighting and/or Exterior Lighting screens. You can generate a report that only contains information on lighting systems in New COMcheck-Web. On the Compliance screen click Reports, then check the box next to the lighting report sections you want included in the report, then click Generate.
Mechanical: Enter mechanical system information on the Mechanical screen. COMcheck does not calculate an overall pass or fail for mechanical inputs/systems so you won't see a compliance result. The Mechanical Compliance Certificate in the report provides the details of the systems and energy code requirements applicable based on the systems shown. COMcheck also provides a mechanism to display whether applicable mechanical code requirements will be met or do not apply based on what you have entered in the Requirements tab, which your local building official may then verify from the resulting checklist that is included in your COMcheck report.
The IECC states that commercial occupancies must comply with the commercial portion of the code and residential occupancies must comply with the residential portion of the code.
ASHRAE Standard 90.1 addresses high-rise residential and all other commercial buildings. Residential spaces are those used primarily for living and sleeping and include dwelling units, hotel/motel guest rooms, dormitories, nursing homes, patient rooms in hospitals, lodging houses, fraternity/sorority houses, hostels, prisons, and fire stations.
If you have a mixed use building with residential and commercial components, you should create a project in REScheck for the residential portion and a separate project in COMcheck for the commercial portion.
Walls that do not fit into any of the preset categories in the software (preset categories come directly from the applicable code selected) may be entered under the "Other" wall type. When "Other" is chosen as the wall type, the software requires an overall U-factor for the assembly. The assembly U-factor is calculated from the spacing of any framing and its R-value, the R-value of installed insulation, and the R-value of the balance of assembly (items such as OSB sheathing, drywall, and interior and exterior air films).
Details of how to perform a U-factor calculation can be found in any basic heat transfer textbook or handbook. You should include your calculation for the building official when submitting the compliance report.
Fenestration is considered anything that transmits light, however, COMcheck cannot calculate fenestration without having a wall associated with it. In this case the wall is entirely fenestration therefore, the square footage would be the same for both the wall and window area, and the software will calculate the wall area as net zero since the fenestration is the entire wall.
In COMcheck, first add a wall and select "Other (U-factor option).” Then enter the square footage of the wall system (e.g., 100 sq. ft), wall orientation, and U-factor.
After defining the wall, add a window assembly and select "Other.” Then enter the same square footage of the wall system (e.g., 100 sq. ft.) and all other required window values (projection factor, U-factor, etc.).