Article #1498 - COMcheck Web-Based Training Questions - Mechanical

This article contains questions asked during the August 18, 2005 live broadcast of the COMcheck Web-Based Training session. The original language of the questions and answers has been modified to make them as generic as possible while retaining the applicable specific information.

Why doesn't Mechanical equipment matter? The EER doesn't make a difference?

Mechanical inputs in COMcheck are optional. The program does not compute a pass or fail. The efficiencies of the equipment that are entered into the program will make a difference in the requirements that are generated in the mechanical compliance report. The report is a summary that is generated according to the systems that are entered in the program and is additional requirements to meet the energy code for mechanical systems.

Why can't the mechanical portion of the report be defined as compliant or not compliant?

Because most requirements in the mechanical section of the energy code are mandatory, the Mechanical section of the software works somewhat differently from the Envelope and Lighting sections. Rather than generating a numerical compliance index, the Mechanical section generates a customized list of mandatory requirements applicable to the mechanical components you identify.

How do you define heating/cooling system efficiencies up front?

Heating and cooling equipment efficiencies are input on the Mechanical screen.

Does the software allow you to identify cooling and heating produced by a central plant that is remote from the building (i.e. campus chilled water, steam)?

Yes, you input the characteristics of the central system since this is the source of heating/cooling for the building.

How does the reviewer know what we use for our HVAC load calculations?

Heating and cooling system design loads for the purpose of sizing systems and equipment should be determined in accordance with generally accepted engineering standards and handbooks acceptable to the adopting authority and plan reviewer.

For a closed-loop geothermal heat pump (with closed loop piping buried in a trench or in wells) do you enter "ground water coupled" or "closed loop"?

If the unit is a simple ground buried system, this is closed loop.

What ventilation is required commercial per square ft. (90.1)?

Ventilation requirements are specified in ASHRAE Standard 62-1999. To obtain this standard go to the American Society of Heating, Refrigerating and Air-Conditioning Engineers website.