Hi All,
I am working on a New Construction, 299 dwelling unit Apartment building, pursuing Option D. All apartments have their own electric meter, paid directly by the tenants. The apartments represent over 68% of the overall energy usage of the building (based on the proposed EAc1 simulation).
How is one supposed to calibrate the proposed simulation when 1) the owner doesn't receive any of the tenants energy bills 2) energy consuption/demand are greatly dependent on the tenants living habits (T'stat set points, occupancy, lifestyle, etc)? Obviously, some type of data sampling (for measurement) could take place, but it would also require the tenant submitting their electric bills (and hopefully a statement of t'stat setpoints).
What is a recommended sampling rate? What is a realistic calibration tolerance when so much of the energy usage is dependent on occupant lifestyles?
I assume the sampling is used to project an average for the tenant spaces. If that is the case, what would trigger 'corrective actions' for tenants, since any deviations from projected saving could easily be assumed to be caused from Tenant lifestyle?
Any suggestions would be helpful.
Thanks,
Josh
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
April 10, 2013 - 10:28 am
I think that sampling could work for a project like that. Off the top of my head something like at least 10% of the units would need to be included. In addition to the overal electric usage you would need to figure out how to determine energy use by end use (lighting, HVAC, plug loads, etc.) within each of the sampled units. How you do that would need to be part of the Plan.
Typical tolerances are +-10% on a monthly basis for each energy end use.
Corrective actions are triggered if the savings are not within the tolerance following the calibration.
You would also need to extrapolate the results of the sample to the whole building and the entire building calibration would need to be within the established tolerance.
Unfortunately apartment building are much more difficult to do correctly than many other building types so this credit is not often pursued for this project type.