Heat Efficiency Pumps: Rewriting the Story

Data shows that a heat pump adds value to a home and offers homeowners more independence and resilience.

As a high-performance technology critical to the country’s low carbon energy transition, heat pumps have had roadblocks from day one. The product’s entry into the market was immediately challenged by poor nomenclature. While some understand the technology and have been strong advocates, the uphill battle against that name continues.

Other products have suffered from confusing names, too—spud wrenches, cat’s paws, dog’s legs—yet, those tools benefit from distinct functions and memorable names that are self-defined, similar to more common names like walk-in closet or mudroom.

The discreet, flush-mounted Mitsubishi Electric ceiling cassette unit blends seamlessly with the modern kitchen aesthetic, offering energy-efficient, zoned comfort without sacrificing style or ceiling space.Courtesy Mitsubishi Electric Trane HVAC US

Having a bad name hasn’t stopped manufacturers from trying to improve the technology and the heat pump has improved leaps and bounds in extreme hot and cold weather performance, it has dropped in price since its introduction, and there are now variable-speed compressors as well.

“Heat pumps are a technology, and like lots of technology, they get better over time as more people buy them and as more manufacturers enter the game,” said Cooper Marcus, CEO at QuitCarbon. “Most people recollect them from 20 years ago, and they weren’t nearly as good as they are now, just like cell phones. Like a lot of technologies, things have come a long way.”

Marcus describes QuitCarbon as a concierge service to direct homeowners to easier, cheaper, better electrification. The company provides free advice by first understanding the design and operations of the home, then outlining the opportunities and connecting the homeowner to a contractor or a rebate.

When Marcus started a personal home remodel project to convert his San Francisco house to all electric, he found it to be too complex. So, he hired a consultant and then built a business model out of his experience, which is what QuitCarbon now does.

The Heat Pump Split

Beyond the branding problem, adoption has also slowed due to uncertainty and trust in the technology. According to Green Builder Media’s COGNITION survey, more than 40 percent of respondents aren’t using heat pumps yet and another 40 percent aren’t ready.

COGNITION data also shows some of the barriers that the industry has in adopting them, with cost being the number one hurdle. Marcus says that while pricing for heat pumps has gone down, the prices continue to be mostly labor not parts, which is also reflected in the more than 30 percent of respondents looking for skilled trades to install the pumps along with with easier installation processes.

While heat pumps are well understood globally, in the U.S. the technology is relatively new, but are growing. Heat pumps now are outselling HVAC by a factor of 1.25 to 1.

Similar to most other products, as the industry grows and more manufacturers create heat pump solutions, the technology improves. In the case of heat pumps, they have gotten quieter, they are available in more shapes and sizes, they can be installed in different places, and they have lower operational costs that are now competitive with gas-powered appliances.

“There are indoor heat pumps that have a TV on them so that the machine is almost impossible to see and there is flexibility on where it is installed,” Marcus said.

The disappointing part is that the industry has been motivated almost strictly by value, Marcus said, not by the benefits to climate. The technology does allow people to be more resilient in the face of more erratic energy costs.

“You can’t drill your own oil well, but you can heat your home with electricity, and you can be independent if you want and isolate yourself from the challenges of a fossil fuel industry and take control of your energy independence,” he said.

This wall-mounted Mitsubishi Electric indoor unit seamlessly integrates into this modern space and offers quiet, efficient comfort. Courtesy Mitsubishi Electric Trane HVAC US

Advancing Heat Pump Technology

Scott Libby is a contractor who writes about his heat pump experience, which often means helping customers understand the technology and reconciling misconceptions.

“Certain systems can provide up to 100 percent heating capacity, even when temperatures plummet to -negative five degrees – all while saving between 40 percent to 60 percent of what their energy bills would be with conventional HVAC units,” he wrote. “We’re the most northeastern state in the country, still getting snow in April, and yet my 1850s farmhouse has not burned fossil fuels in 17 years.”

Ken Johnson is a regional sales manager at Mitsubishi Electric Trane HVAC US LLC and says the company has put extra effort into cold climate heat pump innovation in the past couple years, introducing a hyper heat product that can remain efficient at negative 13 degrees. This advancement has increased Mitsubishi’s market share in northern states, including Alaska.

This progress is helping heat pumps replace the gas furnace, even outpacing the sales of gas furnaces for three years in a row according to Rewiring America.

Mitsubishi also developed quieter heat pumps that can slow down to “cruise control” and use very little energy while consistently holding a temperature.

“It takes longer to get the air to the set temperature, but once it gets to that set point, we call that the mean radiant temperature, and it’s really easy to maintain it when it gets to that temperature,” Johnson said.

Another key area of development for Mitsubishi was maintenance. For example, the company designed removable filters that can be rinsed and put back in the heat pump to last longer. The company also can apply dual barrier coating to improve pump efficiency by preventing hydrophilic dirt and hydrophobic dirt, such as dust, fibers, oils and smoke, from penetrating and staying on components.

Mitsubishi also has a heat pump that can fit between 16” joists and doesn’t require an access panel, which makes it easy to install in typical construction and therefore a very popular option with builders.

Another key development is part of a global push to change the pump’s refrigerant. While the original refrigerant had good performance, it was about 2,000 times more harmful than C0₂ if leaked. Mitsubishi has moved all pumps to the new refrigerants and also offers pumps that come pre-charged with refrigerant and don’t need as much and can have longer line sets.

The Next Evolution

“The need for new solutions isn’t theoretical,” said Kenneth Munson, CEO at Harvest, a home heating and cooling innovator. “In single-family homes, peak heating already pushes transformers and feeders past capacity. In multifamily buildings, utility limits delay projects. And for utilities, unmanaged heating creates a massive new winter peak—at odds with decarbonization goals and ratepayer affordability.”

This is where Harvest found a market entry point, pairing thermal storage with AI and machine learning controls. The company’s technology can decouple heat pump operation from heat delivery by storing energy in insulated water tanks, which then turns a home into a flexible, behind-the-meter battery. Moving the energy draw from peak hours to off peak hours and dispatch it as needed.

So, it can then optimize heat pumps by avoiding peaks, syncing with grid signals, and tracking carbon intensity—even lowering peak demand by up to 50 percent.

Harvest is using AI to improve installation, add predictive monitoring, and to integrate more broadly into a smart home.

“We are looking at having contractors that have 100 or 150 systems in their territory and we’ll be able to monitor them in aggregate and mechanical behavior and making predictive maintenance more accurate and reliable,” Munson said.

He says that installation of the Harvest system isn’t more difficult than a hot water heater and amounts to about two or three days for a team. Harvest plans to start manufacturing the hot water heater as well to combine it all in one system that has additional efficiencies and cost savings.

The Pump’s Future

QuitCarbon’s Marcus anticipates that heat pump efficiency will continue to improve, specifically delivered by Harvest’s battery technology.

“Today all heat pumps must be connected to electricity, and they have to be connected to the maximum amount of electricity it would use at any one time with a big wire that takes up a big chunk of electrical budget of the home,” he said. “With a battery, it can use off peak, low carbon energy. It can be connected to a much smaller electrical and it has lower installation costs, and the need to increase home electrical capacity. We’re on the cusp of this—we’ll see it within a year.”

More innovation will not change the name though.

“The naming ship has sailed. It’s too bad that they are stuck with this name. there are too many players to change the name. it’s impossible. We’re calling them heat pumps. That’s what they’re going to be,” Marcus said.

Mitsubishi’s short-term future has all heat pumps with built in WiFi with a connection to the company’s Comfort App so the homeowner can control all units from a mobile device. Johnson says that the Comfort App also will be able to proactively tell a homeowner that there is something wrong with the system or flag maintenance or even contact a contractor.

Mitsubishi also is rolling out an AI assistant to answer all questions related to operations and installation of its heat pumps to save time and frustrations for those doing the install.

While increased competition and production is not helping drop the costs at the moment, partially due to tariffs, there is data that shows that a heat pump adds value to a home more valuable, not to mention more independence, and more resiliency—a win-win-win.

Publisher’s Note: Green Builder's 20th Anniversary celebration is sponsored by: Carrier, Trex, and Mohawk.