NT-87-20-2 — Combination Warm Air Space Heating/Potable Water Systems

Combination warm air space heating and potable hot water systems employing potable water for both space heating and for the taps are referred to as forced warm air potable water source space heating (PWSSH) systems. Five such systems representative of several hundred installed in Ohio since 1980 are described herein. Operating experience and energy consumption relative to conventional separate gas space heating and water heating equipment is reviewed. Installation economics and local code acceptance requirements are also addressed.

Operating experience has been generally good. PWSSH equipment has proven to be the lowest-cost approach to providing conversion of certain all-electric residences to gas space heating and gas water heating. For the five PWSSH systems described in this paper, gas consumption for space heating and water heating was less thanfor separate gas appliances with comparable efficiency and/or AFUE ratings.