RC-1 Calculation of End Use Energy Loads for Code Compliance Determination
The energy loads for heating, cooling and hot water in the Proposed Design home shall be normalized to account for the differences in improvement potential that exist across equipment types using the following formula in accordance with the paper "The HERS Rating Method and the Derivation of the Normalized Modified Loads Method," Research Report No. FSEC-RR-54-00, Florida Solar Energy Center.
where:
nMEUL = normalized Modified End Use Loads (for heating, cooling or hot water) as computed using Commission-approved compliance software.
REUL = Standard Reference Design home End Use Loads (for heating, cooling or hot water) as computed using Commission-approved compliance software.
EC_r = estimated Energy Consumption for the Standard Reference Design home's end uses (for heating, including auxiliary electric consumption, cooling or hot water) as computed using Commission-approved compliance software.
and where:
where:
nEC_x = normalized Energy Consumption for Proposed Design's end uses (for heating, including auxiliary electric consumption, cooling or hot water) as computed using Commission-approved compliance software.
EC_r = estimated Energy Consumption for Standard Reference Design home's end uses (for heating, including auxiliary electric consumption, cooling or hot water) as computed using Commission-approved compliance software.
EC_x = estimated Energy Consumption for the Proposed Design home's end uses (for heating, including auxiliary electric consumption, cooling or hot water) as computed using Commission-approved compliance software.
EEC_x = Equipment Efficiency Coefficient for the Standard Reference Design home's equipment, such that EEC_x = the energy consumption per unit load in like units as the load, and as derived from the Manufacturer's Equipment Performance Rating (MEPR) such that EEC_x = 1.0 / MEPR for AFUE, COP or EF ratings, or such that EEC_x equals 3.413/MEPR for HSPF, EER or SEER ratings.
For simplified system performance methods, DSE_r equals 0.80 for heating and cooling systems. However, for detailed modeling of heating and cooling systems, DSE_r may be less than 0.80 as a result of part load performance degradation, coil airflow degradation, improper system charge and auxiliary resistance heating for heat pumps. Except as otherwise provided by these Standards, where detailed systems modeling is employed, it must be applied equally to both the Standard Reference Design and the Proposed Design homes.
EEC_r = Equipment Efficiency Coefficient for the Standard Reference Design home's equipment, such that EEC_r equals the energy consumption per unit load in like units as the load, and as derived from the Manufacturer's Equipment Performance Rating (MEPR) such that EEC_r equals 1.0/MEPR for AFUE, COP or EF ratings, or such that EEC_r equals 3.413/ MEPR for HSPF, EER or SEER ratings.
REUL = Standard Reference Design home End Use Loads (for heating or cooling) as computed using Commission-approved compliance software.
and where the coefficients 'a' and 'b' are as defined by Table RC-1(1).
| FUEL TYPE AND END USE | a | b |
| Electric space heating | 2.4026 | 0.0000 |
| Fossil fuel* space heating | 1.0370 | 0.2962 |
| Biomass space heating | 0.7297 | 0.1583 |
| Electric air conditioning | 4.1020 | 0.0000 |
| Electric water heating | 0.9500 | 0.0000 |
| Fossil fuel* water heating | 1.3774 | 1.2217 |
| * Such as natural gas, LP, fuel oil | ||