Water-to-Air Heat Pumps: Basic Terminology & How They Work John Siegenthaler This is the eighth in a series of Heat Pump 101 videos from instructor and author, John Siegenthaler, P.E.. “Air-to-Air Heat Pumps” was the previous lesson in the series. You can enroll in John’s Heat Pump 101 course for free to learn the very basics of heat pumps in less than an hour. Water-to-air heat pumps operating in heating mode: Absorb low temperature heat from any water source (typically ground water or soil) Increase the temperature of that heat using a vapor compression cycle Deliver the higher temperature heat to the building using a forced air distribution system. Water-to-air heat pumps operating in cooling mode: Absorb low temperature heat from inside air Increase the temperature of that heat using a vapor compression cycle Dissipate the higher temperature heat to a stream of water (typically ground water or flowing through tubing buried in the ground) Other things to know: The most commonly-used heat pump in geothermal applications Mounted indoors Available with vertically-oriented or horizontally-oriented cabinet Pre-charged with refrigerant at factory Refrigeration systems with extended range used for geothermal applications, and narrower range for commercial water loop HP applications. Single unit common in average residential application. Multiple units common in commercial applications Available for single phase or 3-phase power Some units equipped with “desuperheater” to heat domestic water whenever compressor is running The next video in this series describes how water-to-water heat pumps work. If you want to see that video now or jump ahead to the others, you can find them all in John Siegenthaler’s free Heat Pump 101 course. Free Courses Geothermal Heat Pumps Heat Pumps Originally posted on July 3, 2023 Written by John Siegenthaler John Siegenthaler, P.E., is a mechanical engineer and graduate of Rensselaer Polytechnic Institute, a licensed professional engineer, and Professor Emeritus of Engineering Technology at Mohawk Valley Community College. “Siggy” has over 35 years of experience in designing modern hydronic heating systems. He is a hall-of-fame member of the Radiant Professionals Alliance and a presenter at national and international conference on hydronic and radiant heating. John is principal of Appropriate Designs – a consulting engineering firm in Holland Patent, NY. The 3rd edition of his textbook – Modern Hydronic Heating – was released in January 2011. John currently writes about hydronic heating and solar thermal system design for several trade publications. More posts by John