California Association of Building Energy Consultants

Choosing Electric Water Heating

This article discusses electric water heating as a choice to provide hot water use in a residential home and if these water heater types can meet the 2019 Title 24 Part 6 Energy Code. In general there are 3 types of electric water heaters available for residential home use:

  1. Electric Heat Pump Water Heater
  2. Electric Tankless Water Heater
  3. Electric Storage Water Heater

#1. Electric Heat Pump Water Heater

First, here is some information about an electric heat pump water heater from the Department of Energy (DOE) website:

How They Work

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric resistance water heaters. To move the heat, heat pumps work like a refrigerator in reverse.


This utility room includes a heat pump water heater
Photo courtesy of Thomas Kelsey/U.S. Department of Energy Solar Decathlon

This type of water heater will meet the current Title 24 Part 6 Energy Code in all cooling climate zones in the State of California. (Note, a cooling climate zone is a geographical area that needs cooling due to warmer temperatures. Lake Tahoe or Big Bear Lake are not cooling climate zones). Note, compliance is met by specifying a particular brand and model electric heat pump water heater. If this particular brand and model heat pump water heater is not installed, the home may not pass final inspections and that, in turn, may cause a revision to the Title 24 Part 6 CF-1R energy report at the end of the building process. So, to ensure that a Title 24 Part 6 CF-1R energy report will be valid from the initial building permit process through the building permit final process please provide the brand and model of an electric heat pump water heater. Below is one example:

Rheem PROPH50 T2 RH350 D

Please contact a plumbing supply store and do not use the internet in a search for this product. Electric heat pump water heaters that pass the 2019 Title 24 Part 6 Energy Code have UEF ratings of 3.2 or better and are NEEA rated.

One additional note. These water heaters generally are installed inside the home or a garage. Most units are not made for outside conditions.

#2 and #3. Electric Tankless and Standard Electric Storage Heaters

These two types of water heater will not meet the 2019 Title 24 Part 6 Energy Code. These units by themselves are too energy inefficient.

However, these types of units may meet the 2019 Title 24 Part 6 Energy Code if a Thermal Solar System is installed.

Definition from Widipedia …

A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar air heaters.

In order to see if a Thermal Solar System will aid in the compliance of an electric tankless or electric storage water heater the following information is needed:

NOTE: Gathering this information now, though it may cause a delay, will ensure that the Title 24 Part 6 Energy Report used for the building permit process will be valid through the entire building permit process.

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