EA credit 3.2 & EA Pre-requisite 1- Submetering

If you are working with an energy auditor, they should be experience in coming up with reasonable estimates for the various energy loads in the building. When submeters aren't installed, you can either base the breakdown on calculations (power drawn multiplied by the runtime of that equipment), or use portable meters to take spot measurements and extrapolate out or an annual time period (taking into account any seasonal variation, of course).

Hi Jenny and Paola, I am currently working on an office building with submeter metering AC, pumps, lift and lighting and equipment power only. Unforturnately, lighting and equipment power is metered together under one meter. The reviewer has requested us to breakdown the lighting and equipment power with estimation. We would then like to propose the estimation by taking code reference of lighting and equipment power density to work out a fraction to estimate the lighting and equipment power consumption separately. For example, with reference to Ashrae 90.1-2007 and Ashrae 90.1-1989 code reference, Lighting power density is 12W/m2; Equipment power density is 16W/m2 Therefore, the estimated power consumption for lighting and equipment is a) 12/ (12+16) * metered lighting & equipment power consumption = lighting estimated power consumption for submission. b) 16/ (12+16) * metered lighting & equipment power consumption = equipment estimated power consumption for submission. In summary, i would like to understand from your experience, do you think this is acceptable by USGBC? Many thanks to your reply. Cheers, YingYing