California Association of Building Energy Consultants

High-Efficiency Water Heater Ready For New Construction and Additions

High-Efficiency Electric Ready for Gas Water Heater

[FROM: 5.3.5 High-Efficiency Electric Ready for Gas Water Heater of the 2022 Single Family Residential Compliance Manual and Section 150.0(n) of the 2022 Building Energy Efficiency Manual]

To facilitate future installations of HPWH, the Energy Codes contain the following mandatory requirements for s gas or propane water heaters. When a gas or propane water heater is installed, the building must be made electric ready to minimize future retrofit costs when gas appliances are replaced with electric appliances. Dedicated space for a future HPWH, and wiring is required to be run to the designated location. Space must also be reserved at the electric panel to serve a future heat pump water heater, and a condensate drain must be installed.

These requirements are for newly constructed buildings and additions (if a water heater is installed in the added floor area), and they are not applicable to alterations. Moreover, these requirements are not applicable when installing an electric water heater.

  1. A dedicated 125-volt (v) electrical receptable that is within 3 feet of the water heater and accessible to the water heater with no obstructions, and be connected to a three conductor, 10 AWU branch circuit. In addition, the unused conductor must be labeled and electrically isolated and have a reserved circuit breaker space.
  2. A condensate drain that is not more than 2 inches higher than the base of the installed waer heater and allows natural draining without pump assistance.

These requirements make it easier for someone to retrofit HPWH in the future. Wiring during initial construction stage is much less costly than trying to retrofit it later.

5.3.5.1 Electrical Receptacle

The goal of this requirement is to allow easy installation of HPWH when the existing gas water heater needs to be replaced. HPWH typically requires a 240-volt circuit, and this requirement allows an electrician to easily convert the 120-volt circuit to a 240-volt circuit.

The electrical receptacle must be installed with 3 feet from the water heater. It should be connected to a dedicated circuit with a 10 AWG copper branch circuit. The ends of the unused conductor must be labeled as "spare" and be electrically isolated.

A reserved single-pole circuit breaker space must be placed in the electrical panel next to the circuit breaker for the branch circuit and labeled with the words "Future 240V Use".

5.3.5.2 Condensate Drain

The requirement for the condensate drain being placed near the water heater and no higher than the base of the tank allows the condensate to be removed without relying on a sump pump.

New Allowance for Electric Tankless Water Heaters

Performance Requirement Changes for Single-Family Residential Buildings

[FROM: §5.2.1 Instantaneous Water Heaters of the 2022 Single Family Residential Compliance Manual]

Electric instantaneous water heaters are not generally designed for use with solar water heating systems or as heat sources for indirect-fired water heaters. They are also typically inappropriate for use with recirculation systems. Consult manufacturer's literature when considering these applications. Electric instantaneous water heaters are not allowed through the prescriptive approach to compliance but can be installed using the performance approach as long as the total energy budget is not exceeded.

Prescriptive Requirement Changes for Single-Family Residential Buildings

[FROM: 2022 Single Family Residential Compliance Manual and 2022 Building Energy Efficiency Manual]

New Prescriptive heat pump domestic hot water equipment requirements are added.

Unless the Performance Method is used, a water heater must be one of the following:

  1. In all Climate Zones: One 240-volt heat pump water heater with a storage tank installed in the garage or conditioned space AND
    1. In Climate Zones 1 and 16 only: HERS-verified compact hot water distribution AND
    2. In Climate Zone 16 only: HERS-verified drain water heat recovery system
  2. In all Climate Zones: One 240-volt, NEEA Tier 3 or greater heat pump water heater installed AND in Climate Zone 16 only: HERS-verified drain water heat recovery system with a storage tank installed in the garage or conditioned space
  3. C. In all Climate Zones: One solar water-heating system, with an annual solar saving fraction of 0.7 or greater, with electric backup and HERS-verified per Residential Appendix RA4

EXCEPTIONS

  1. In Climate Zones 3, 4, 13 and 14 only: Tankless gas or propane instantaneous water heater with an input of ≤200,000 Btuh (no storage tank allowed) when space-heating system is a heat pump per §150.1(c)6
  2. In all Climate Zones in new dwelling units with a conditioned floor area of ≤500 ft²: an instantaneous electric resistance water heater installed with HERS-verified point-of-use distribution
  3. In all Climate Zones: One 120-volt heat pump water heater for a new one bedroom or studio dwelling unit

As always, I am available to discuss the process of meeting the California Energy Code for any building project. Contact me …