Table 30. End Use Categories
End Use Space Heating
MELs OA Ventilation
Potential Electric Usage
Supply fan during space heating, HP*, HP supplemental heat, water boiler heating elements, water boiler circulation pump, electric resistance heating, HP crankcase heat, heating system auxiliary Central split-system A/C**, packaged A/C (window or through-the-wall), supply fan energy during space cooling, A/C crankcase heat, cooling system auxiliary Electric water heater, HP water heater, hot water circulation pumps Indoor lighting, outdoor lighting Refrigerator, electric clothes dryer, gas
clothes dryer (motor), cooking, MELs Ventilation fans, air handler during ventilation mode Photovoltaic electric generation
Potential Gas Usage
Gas furnace, gas boiler, gas backup HP supplemental heat, gas ignition standby
Gas absorption chiller (rare)
Gas hot water heater
None Cooking, gas clothes dryer, gas fireplace None
For attached and multi-family housing, the energy use for all units shall be combined with the energy associated with common areas and any centralized space conditioning or hot water systems. This applies to both the Benchmark units and the Prototype units. Energy savings shall be calculated on a whole-building or whole-complex basis, and each unit shall be deemed to have the same percent energy savings.
The “Percent of End Use” columns in Table 29 show the Prototype energy use for each end use as a fraction of the appropriate base case. The “Percent of Total” columns show the contribution of each end use toward an overall energy reduction goal. Note that site generation for the Benchmark is always zero.
Source energy shall be determined using Equation 22, using the site-to-source multipliers in Table 31.
Equation 22: × Mo,
Source MBtu = kWh × 3.412 × Me /1000 + therms × Mg / 10 + MBtu
M e = 3 . 3 6 5 = s i t e t o s o u r c e m u l t i p l i e r f o r e l e c t r i c i t y ; M g = 1 . 0 9 2 = s i t e t o s o u r c e m u l t i p l i e r f o r n a t u r a l g a s ; Mo = site to source multiplier for all other fuels (see Table 31).
For the purpose of determining whether the Joule energy savings criteria are met, a house size multiplier shall be applied to all Benchmark source energy consumption calculations for Building America homes (or units) that are attempting to achieve 50% energy savings or more. The adjusted Benchmark Source energy (Equation 23) assumes that a typical house size is 2400 ft2 with three bedrooms.