By Anne Fonda
An air to water heat pump (AWHP) is a heat pump that uses water to heat and cool your home. It’s a heating and cooling system that extracts heat from the air, and transfers heat into water or a water-glycol mixture. Because it uses water, it is also known as a hydronic heating and cooling system.
While still emerging as a heating and cooling solution residential applications in the United States, AWHP systems are quite common in Europe as well as commercial buildings in the U.S.
Much like an air source heat pump, an air to water heat pump extracts heat from the air. Using the refrigeration cycle, it heats or cools water in the outdoor unit and distributes it through connected water lines to in-floor radiant tubes, fin tube baseboards, or radiators throughout the home.
When it’s cold out and you turn on the heat, the hydronic heat pump heats the water; when it’s hot out and you need to cool things down, it reverses the refrigeration process, turning into a chiller that sends cold water through the radiant system or fan coil units for whole-house cooling and dehumidification.
The system includes:
There are two main scenarios: you need to replace an aging and inefficient boiler system, or you are building a new home and you desire premiere comfort through radiant floor heating (and cooling). AWHP systems do not need ductwork, making them a great home comfort solution for older homes as well as energy-efficient new construction or renovations.
” You don’t have to choose between a comfortable home and a greener footprint. Most of us don’t upgrade our home’s heating system just to save the planet—we do it to stop worrying about wild winter fuel bills, uneven room temperatures, and drafty floorboards.
The magic of an air-to-water heat pump is that it delivers the coziest radiant warmth and crisp summer air while using a fraction of the energy of traditional boilers. You get luxury comfort and lower operating costs; the massive drop in carbon emissions is simply the bonus you get for making the smart financial choice.”
– Jennie Bergman, Portfolio Leader, Residential Package Units & Light Commercial Unitary
Yes. As we mentioned above, an AWHP system can heat your home in cold weather and cool your home in warm to hot weather. This is part of what makes it such a great alternative to boiler replacement.
“Yes, absolutely! One of the greatest superpowers of an air-to-water heat pump is that it doesn’t just keep your home cozy in January and refreshing in July—it also powers your daily life fulfilling your hot water needs. By letting one ultra-efficient outdoor unit handle your heating, cooling, and showers, you simplify your home, cut fossil fuels, and enjoy pure, reliable comfort every time you turn the tap.”
– Jennie Bergman, Portfolio Leader, Residential Package Units & Light Commercial Unitary
“A traditional boiler makes heat by burning fuel, which caps its efficiency at under 100%. An air to water heat pump does not make heat—it simply moves existing heat from outside into your home.
Because moving heat takes much less energy than creating it from scratch, an air-to-water heat pump runs at 300% to 400% efficiency on average, making it roughly three to four times more efficient than even a brand-new boiler!”
– Jennie Bergman, Portfolio Leader, Residential Package Units & Light Commercial Unitary
Your cost will vary greatly based on several factors, including:
“An air to water heat pump generally costs more to purchase and install upfront than a standard replacement boiler. However, because it replaces three separate appliances (heating boiler, central air conditioner, and domestic water heater) and operates at 300%+ efficiency, the long-term energy savings and available electrification incentives significantly shorten the payback window.”
When looking solely at heating quotes, heat pumps can look more expensive on paper. To make it an apples-to-apples comparison, homeowners should view it as a bundled investment:
| If You Buy Separately | If You Choose Air to Water… |
|---|---|
| New High-Efficiency Gas/Oil Boiler ~$11,000 | One Air to Water Monobloc/Split Unit |
| New Central AC/Mini-Split System ~$8,000 | Integrated indoor hydronic fan coils/radiant cooling |
| Standalone Water Heater ~$2,500 | Dedicated indirect hot water tank tied to the heat pump |
| Combined Total ~$21,500* | Combined Total: ~$18,000-$24,000 (before any rebates) |
*These are rough estimates of equipment and installation costs for these components. Prices will vary by contractor and equipment brand.
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.
When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by Jennie Bergman, Portfolio Leader, Residential Package Units & Light Commercial Unitary
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