Parasitic Energy Use - Prototype Buildings
Hi,
I'm doing some work with the archetype models created with the Create_DOE_prototype_model measure.
I noticed the parasitic energy use rate for water heaters seemed really high and inconsistent (much higher in ASHRAE 169-2013 vs pre-1980).
For example
- large hotel: Pre-1980: 2,301W vs. 90.1:15,908 W
- Medium Office: Pre-1980: 19.9W vs. 90.1: 1,886W
Is this a unit conversion error? In some cases the parasitic load is >50% of the water heater load over the year. The difference in energy use is pretty significant.
Thanks, Cameron
Circulation pipe losses are accounted for as parasitic loads on the water heater, so it may have to do with recirculation requirements. If recirculation is assumed post-1980, but not pre-1980, that would explain the discrepancy.
Would the circulation pipe losses not be included in the loss coefficient or loss fraction rather than parasitic loads? I thought parasitic loads would be related to the pilot light for example.