COMcheck-Plus™ FAQs

COMcheck-Plus has been Discontinued

Q: What is COMcheck-Plus?

COMcheck-Plus is a software tool developed by the U.S. Department of Energy's Building Energy Codes Program, designed to simplify the process of demonstrating compliance with the commercial building energy code using whole-building performance methods.

Q: Where can COMcheck-Plus be used?

COMcheck-Plus is suitable for use in jurisdictions with energy codes based on ASHRAE/IESNA Standard 90.1-1989, such as the ASHRAE 90.1 Code, the 1998 and 2000 International Energy Conservation Codes (IECC), and many state-developed energy codes. Some provisions not found in the 90.1 Standard have been incorporated in COMcheck-Plus to improve ease of use and code enforcement, while ensuring that buildings designed to comply with COMcheck-Plus can be "deemed to comply" with Standard 90.1. However, as with any code-related issue, the local jurisdiction has the final authority to determine whether COMcheck-Plus results will be accepted as adequate demonstration of compliance.

Q: How does COMcheck-Plus simplify use of performance-based energy codes?

To show compliance using COMcheck-Plus™, you need to enter information about your building design using the program's user interface. Once you have entered the building description, COMcheck-Plus takes over, analyzing the performance of the design using the DOE-2.1E simulation program and generating compliance reports that compare your design to the code budget. COMcheck-Plus contains a Building Creation Wizard feature that dramatically reduces the time needed to enter a building description, as well as extensive Help facilities and other ease-of-use features.

Q: How does COMcheck-Plus differ from COMcheck?

Most codes based on Standard 90.1 offer three compliance options: 1) prescriptive, 2) system performance (in which trade-offs are permitted within major sections of the code-envelope, lighting, etc.), and 3) whole-building performance (in which trade-offs are also permitted between major sections of the code). COMcheck-Plus implements the whole-building performance option, which is known as the Energy Cost Budget (ECB) Method in Standard 90.1.

The COMcheck product is designed to make the first two compliance options as easy to use as possible. The printed COMcheck guides offer a simple prescriptive method, while the COMcheck software offers limited performance trade-offs within the envelope and lighting sections. In general, the different compliance options offer trade-offs between simple compliance and design flexibility. COMcheck-Plus is intended to complement rather than replace COMcheck.

Q: When is COMcheck-Plus recommended over COMcheck or other compliance methods?

Reasons you may want to use the COMcheck-Plus software include unusual design features that cannot be shown to comply using other methods (such as large skylight areas), design features that are not fairly treated under simplified methods (such as certain fixed-shading surfaces), a desire to optimize the building design (for example, to meet efficiency requirements at the lowest construction cost), or interest in documenting above-code performance.

Q: What are the computer system requirements for COMcheck-Plus?

COMcheck-Plus operates on computer systems running Windows NT, 95, 98, 2000, or XP operating systems. Minimum hardware requirements are an Intel Pentium (or equivalent) microprocessor, 16 MB RAM, 20 MB free hard disk space, and a Color VGA monitor (800x600 minimum resolution). The program will NOT run under Windows 3.1 or DOS operating systems, on UNIX machines, or on Macintosh computers without the use of a Windows emulator.

Q: What support is available for COMcheck-Plus users?

Technical support for COMcheck-Plus is no longer provided.

Q: How can I get COMcheck-Plus?

You can download COMcheck-Plus from this website at no cost.