27 October, 2020
Heat Pump Water Heater Technical Guide for Multifamily
Heat pump water heaters (HPWHs) are now more available, efficient and reliable than ever, with many products carrying a 10-year warranty. As water heating accounts for roughly 25% of multifamily building energy use, HPWHs can dramatically reduce the energy load of the entire building.1
In this guide, you’ll find installation tips and best practices for R-2, low-rise multifamily new construction buildings that are three stories and fewer, as well as information on achieving 2-3 credits from Washington State Energy Code (WSEC) Table R406.3.
HPWHs are most effectively integrated into multifamily buildings if considered from day one of the design process. There are several design features that must be considered for the HPWH to work—specifying a HPWH for a multifamily building involves more than simply specifying a tank with an increased efficiency rating.
This technical guide will help you understand these considerations and provide solutions to common design challenges. There is no one-size-fits all application option for HPWH in R-2 occupancy. The best system for your building will depend on factors including number of units, type and size of units, number of floors, presence of parking garage, roof access, balcony presence/absence, and interior or exterior corridors.