Hi all,

I need help with these three questions:

Case 1) when a proposed building is supplied with purchased chilled water, but a VRV system serving a server rooms is supplied with electricity, what energy source should be used for HVAC System 3 which is serving the server rooms in baseline building? DX or purchased chilled water? The main baseline system is System 7. I am asking due to section G3.1.1.3 of ASHRAE Standard 90.1-2010.

Case 2.1) the proposed building cooling source is supplied with natural gas (gas heat pumps). No additional cooling source is installed. The question is what energy type should be used in baseline? According to G3.1.3.7 Type and Number of Chillers, electric chillers should be used regardless of cooling energy source of proposed building. It is OK to report cooling energy performance within the PRM Compliance Report in two separate rows, one for electricity (zero kWh proposed vs XY kWh baseline) and one for natural gas (XY kWh proposed vs zero kWh baseline)? Or just use different energy rates and provide a narrative?

Case 2.2) if additional cooling source is installed as a support to the gas heat pumps, e.g. an electric water cooled chiller, is there any change in the baseline cooling energy type against the case 2.1? Can be the PRM Compliance Report prepared similarly like in the case 2.1?

Thanks in advance for any suggestions.

Martin