Can We Talk About Air-To-Water Heat Pumps, Please?
There’s something addictive about the hunt for the latest shiny object. You think, This time, this is it. If I can just get this one thing, I’ll be complete. Thankfully, it’s been years since an obsession like this has taken hold of me.
One of the last times was in 1996. The object in question? A Chevy Tahoe. The latest model had just been released with the first new engine design in years. I spent hours—days—trying to get one, relishing the challenge of finding one at a dealer. Finally, I located one at a dealership on the New Jersey Shore. The dealer told me he had only one left. He was driving it himself because it was an aftermarket model. What does that mean? Many things, like it being an extra few inches off the ground, which didn’t interest me. However, when I saw the prom lights in the ceiling above the center console, which was teak…well, that sealed the deal.
But thankfully, my current obsession is more in line with my values these days. It’s the thrill of finding the right high-performance air-to-water heat pump.
Just to warn you: on our morning walks, my wife has developed a sixth sense—she can sniff out a heat pump conversation before I’ve even opened my mouth. She’s taken to muttering, “Here we go again,” as a preemptive strike, which I usually choose to ignore. The topic is that enthralling to me.
I even drove an hour north of St. Paul to attend a building science gathering in Pine City, MN, aptly named “BS and Beer.” What did I discuss? You guessed it—air-to-water heat pumps. There was someone there who works with and is installing the Arctic brand in a cabin he's building for a client.
But that is a rarity. There aren’t many of these systems in Minnesota, especially. The cold climate here has kept people away from the idea, but that is starting to change.
Air-to-water heat pumps are popular in Europe. They’re going gangbusters in China and Japan. There are residential installations here in the USA, but more so in commercial buildings.
What most of us think of as heat pumps are the air-to-air varieties that pull heat or cooling out of the air and then pump it into the air inside through ductwork or mini-splits on the wall. This is different. Air-to-water heat pumps use, you guessed it, conditioned air to heat or cool water that runs through pipes and radiators.
What’s the catch? The heat they provide is at a lower temperature than a natural gas boiler, which, as the name implies, was originally designed to boil water for steam. So in our case, unless we install floor, wall, and/or ceiling panels to supplement or existing ancient cast iron and baseboard radiators, it looks like we’d need to swap out most of our emitters for newer, low-heat varieties. Like with air-to-air heat pumps, we’d also need to tighten up our house to be in line with a reduced heating load so the system can work efficiently.
I think it’s worth it - figuring out a solution could be a game changer for providing clean heat in homes in colder climates where radiators are more prevalent. They can electrify a home and replace natural gas, propane, and oil-fired boilers. Air-to-water systems can also distribute can even provide domestic hot water as well not to mention cooling in the summer. For this reason, new builds are opting for these systems as well.
As mentioned in an earlier post, CEE, the widely-known Minnesota energy efficiency nonprofit, contacted me about a study they were proposing on air-to-water heat pumps with thermal storage. This was most likely a follow-up to their first study on air-to-water heat pumps in Minnesota, undertaken for the MN Department of Commerce which wrapped up in December of 2023. For that first study, they installed four air-to-water systems around Minnesota (think Die Hard Battery commercials filmed in International Falls, MN). They used heat pump systems from Enertech Global and Electro Industries. Electro pairs its NorAire EB-HPH with a Bosch BOVA outdoor air-to-air heat pump. So, it is called a split, third-party system. It is the cheaper of the two systems.
After some fits and starts with the set up, all systems functioned well, with the Enertech system seeming to be the standout for efficiency and performance—even in Minnesota’s cold climate.
I called Enertech and found out that their heat pumps are manufactured in Mitchell, South Dakota. I spoke to the customer service representative and asked about installers. She mentioned that their strongest U.S. regions are in the Pacific Northwest and Northeast, and she didn’t know why it hasn’t caught on in more home in the Midwest. She gave me the name of an installer across the St. Croix River in Wisconsin.
Dean Havel is the director of technical support at Electro Industries and said they have been supporting air-to-water systems since 2014. While the company traditionally has been focused on electric boilers, he sees things changing, with growing interest in harnessing heat pump technology. The Minnesota based company was recently purchased by Laars Heating Systems, a subsidiary of Bradford White Corporation. Laars has a long-standing reputation in the gas-fired heating industry and may have purchased Electro Industries technology and assets to future proof its business.
I've been eager to speak with the Canadians about their air-to-water heat pump experiences after someone told me they seem to be light years ahead of us in adoption. I reached out to Michael Ridler, a Canadian who conducts training for installers of air-to-water heat pumps on behalf of his wholesale firm, Eden Energy. He also presents at equipment conferences, and I found air-to-water heat pump recordings from Eden Energy on YouTube.
He wrote back, saying, “The air-to-water market is rapidly developing, especially as we see a race to replace boilers with more efficient options.”
Race?
Yes, the Canadians have distributors like Ridler who are training hundreds of installers. While in the USA, we have to contend with what the CEE study concluded was the central challenge of this exploding technology: “Finding qualified or even willing installers was a significant hurdle for this field project; homeowners exploring AWHP technologies independently will likely continue to struggle similarly until the market grows.”
That means I need to ramp down my obsession of having one installed in our home soon, lest I come across an installer offering one with built-in prom lights—and I become overtaken by the same indiscretions I had in my younger days.
So, we’ve learned that air-to-water heat pumps have the promise to help—if you tighten up your house, if you find the right system, and if you can find someone to install it.
