The EDR1 score is a metric of a building’s hourly source energy divided by the reference design hourly source energy budget. An EDR1 score is calculated for the proposed design and a second EDR1 score is calculated for the standard design. The proposed design EDR1 must be equal to or less than the standard design EDR1.
An EDR2 score of zero represents a building that has zero-net-energy performance based on the TDV energy consumption, and an EDR2 score of 100 represents a building that is minimally compliant with the 2006 International Energy Conservation Code. The EDR2 score is a ratio of a building’s TDV budget to reference design TDV budget.
An Efficiency EDR2 and Total EDR2 score are calculated for the proposed design and a second Efficiency EDR2 and Total EDR2 score are calculated for the standard design. Compliance with EDR2 requires meeting two criteria:
1. Proposed design Efficiency EDR2 must be equal to or less than standard design Efficiency EDR2. The EDR2 is established by the ratio of the standard design or space heating, space cooling, IAQ ventilation, water heating, and self-utilization credit energy consumption, and reference design energy consumption of the same end uses.
2. Total EDR2 (Efficiency EDR2, plus PV/flexibility EDR2) of the proposed design must be equal to or less than the Total EDR2 of the standard design. The Total EDR2 is established by the ratio of the standard design or proposed design efficiency end uses plus interior lighting, appliances, cooking, plug loads, exterior lighting, and PV generation and flexibility measures energy consumption of the standard design and the total EDR2 of the reference design.
The standard design efficiency is based on the prescriptive requirements in Table 150.1-A. The 2022 Energy Code prescriptively requires heat pump space heating in climate zones 3, 4, 13 and 14, and heat pump water heaters for domestic hot water (DHW) systems in all other climate zones. Additionally, a new exception for cooling ventilation has been added for new single family dwellings with a conditioned floor area of 500 square feet or less. There also is a new exception for an instantaneous electric resistance water heater with point of use distribution for new single family dwellings with a conditioned floor area of 500 ft2 or less.
Variable capacity heat pumps will require verification of the following features: (1) installed system must have refrigerant charge verified according to the applicable procedures in RA3.2; (2) ducted indoor units shall be verified to meet the verified low-leakage ducts in conditioned space requirements according to the procedure in RA3.1.4.3.8; (3) ductless systems shall be verified to visually confirm ductless indoor units are located entirely in conditioned space, (4) confirm that all habitable rooms are provided with conditioned airflow; (5) confirm zones greater than 150 square feet have a wall mounted thermostat; (6) confirm that the manufacturer’s model number of installed ducted units are included in listings of certified low-static pressure VCHP system published on the Energy Commission’s website; (7) if non-continuous fan operation is claimed for credit in the compliance software, verification shall confirm that the installed system’s indoor unit + outdoor unit combination is certified to the Energy Commission and listed on the Energy Commission website as a type that does not operate the fan continuously by default; (8) each new ducted indoor unit must have airflow verified to confirm the airflow at full capacity in cooling mode is equal to or greater than 350 cfm/ton of nominal cooling capacity of the indoor unit, and 300 cfm/ton for altered systems; and (9) verification shall confirm the air filter sizing is correct, and confirmed the installed air filter label specifies performance that meets a clean filter pressure drop less than or equal to 0.1 inch wc. at design airflow rate.