Renters, you too can get a heat pump — a micro one, at least

Micro” heat pumps aren’t as powerful as whole-home versions, but they’re portable, plug into a 120V outlet — and they’re increasingly effective in the cold.
By Alison F. Takemura

  • Link copied to clipboard
Living room with white and black micro heat pump, a.k.a. portable AC with heat, with a hose fit into into the window frame.
This micro heat pump cools and heats small spaces. (Frigidaire)

Canary Media’s Electrified Life column shares real-world tales, tips and insights to demystify what individuals can do to shift their homes and lives to clean electric power. 

Heat pumps are hot solutions for a cooler climate — and for good reason. They’re key to decarbonizing home heating, the average home’s biggest energy hog. They double as air conditioners and can both clean up indoor air quality and lower energy bills.

But what options are available to renters who want to heat their homes without fossil fuels (aside from including an ode to heat pumps with your next rent check)?

Ripping out an existing heating system and replacing it with a full-size heat pump might not jibe with a landlord nor be possible in a multifamily building with central heat. Even if it’s doable, a switch is unlikely to make financial sense for the 44 million households that rent in the U.S. Not many people are going to spend more than $10,000 on a new heating and cooling system for a home they don’t own.

Enter micro” heat pumps. They’re not as powerful or efficient as whole-home heat pumps, but they’re portable, plug into a standard 120-volt outlet (no electrical upgrades required), and are a fraction of the cost. You may even have seen one without realizing its potential; they’ve historically been marketed as portable air conditioners, with heating as an afterthought.

Micro heat pumps that function as dual AC/​heaters make up only a tiny sliver of the pool of portable AC models available in the U.S.: just 2 percent, or 37 offerings, according to the U.S. Department of Energy. But the growing buzz around movable two-way heat pumps, forthcoming models designed to work in colder climates, and anticipated incentives from the Inflation Reduction Act could catapult these devices into the hands of more renters.

Micro heat pumps for mild climates — a.k.a. portable ACs with heat

Volunteer-based electrification group Electrify Now has called micro heat pumps a great solution for renters.” These portable 60- to 90-pound devices are twice as efficient as fossil-fuel and electric-resistance systems. Commonly referred to as portable ACs with heat, they’re DIY-installable, widely available from home goods stores and cost about $500 to $700. (But pay close attention to product specs: some portable ACs with heat use inefficient electric-resistance heating rather than heat pumps.)

Micro heat pumps are also simple to set up. Some fit in windows, just like a window-AC unit, and others are freestanding with hoses that mount in window frames in order to draw heat from outdoor air in the winter and dump heat outside in the summer. 

Real-world collage of photos of portable heat pumps with ducts that fit into window frames in people's homes.
Micro heat pumps for mild climates can fit into a renter’s life. (Electrify Now)

But these bite-sized heat pumps have two major limitations.

First, they’re designed to heat and cool the equivalent of a large room or, at most, a small studio. The Midea Duo 12000 Btu model, for example, can heat up to 550 square feet. Bigger spaces might require more than one device. Exactly how much area a unit can handle, though, will depend on your local climate and how airtight and well-insulated your home is.

Second, the micro heat pumps available now only work in temperatures down to about 40˚F, so they’re best for mild climates and for reducing reliance on fossil-fuel heating in places where temperatures drop lower.

Electrify Now and collaborators have tested a number of portable heat pumps. Based on their research, Electrify Now has four top models it recommends, offerings from Whynter, Frigidaire, LG and Midea.

A comparison table of 8 different models of portable heat pujmps. The Midea model costs $650 and can heats w/ 12k BTU/hour
Electrify Now’s favorite portable heat pumps, underlined in green. The heating capacity (Btu per hour) is given in orange. For the “Drain Pump” and “Swing Fan” categories, green indicates presence; red, absence. For “Drain Hose,” “Window Kit” and “Good Manual” categories, green, yellow and red are qualitative ratings, with green being best and red being worst. (Electrify Now)

Two of these models have an energy-efficient two-hose design, and all four have condensate pumps to allow them to drain collected water more conveniently (including outdoors); the Midea model also has a variable-speed inverter that allows it to sip energy instead of guzzling it.

The condensate-pump feature looms disproportionately large for users. Condensation happens when damp, warm air hits the heat pump’s cold coils of refrigerant. Without a pump to push condensate water outside or to a drain, these machines can quickly become a pain. That’s been the experience of Jesse Nienow-Macke, AmeriCorps member and climate justice project coordinator for Portland Public Schools. He rents a 1,300-square-foot apartment on the city outskirts and interned with Electrify Now in 2022, testing a micro heat pump.

Nienow-Macke currently owns two models, a Whynter and a DeLonghi, that lack condensate pumps. He uses them to cool his apartment when heat waves top 100˚F, but he relies on them less than he’d like in the winter because they collect so much water. When they’re in heating mode, he needs to empty them every four to five hours. What’s worse, the drains are only a couple of inches off the floor, so there’s not enough room for him to stick a container under them to catch the water; he has to haul his micro heat pumps to the stairs to get enough clearance.

Tape measure next to portable heat pump drain about 2  in. from floor. On right, drain flowing water to tray on stair below.
Without a condensate pump and because the drain is inconveniently low, Jesse Nienow-Macke has to empty his portable heat pumps by hauling them to the stairs. (Jesse Nienow-Macke)

He strongly recommends that buyers interested in a micro heat pump purchase one with a condensate pump.

Coming soon: Cold-climate micro heat pumps

A couple of forthcoming micro heat pumps could soon help renters weather colder winters. Startup Gradient and global appliance-maker Midea have both announced plans to release apartment-friendly heat pumps that work well in temperatures below zero.

As more capable machines, they’ll have a big jump in price from mild-climate micro heat pumps. Midea tells Canary Media its packaged window heat pump” will cost $3,000; Gradient says their model will cost $3,800.

A boxy half of a white heat pump that straddles a window frame faces the interior of an apartment with potted plants.
Forthcoming cold-climate heat pumps that sit in your window could help renters wean off fossil fuel heating. (Gradient)

These versions sit across a sash-style windowsill, with the two halves of the unit hanging down on either side like saddle bags. The design allows residents to enjoy their views and lower noise levels, as the machine’s compressor is on the outside of the building.

Another advantage of these units is that they evaporate pesky condensate, so residents don’t have to empty a reservoir.

Both cold-climate micro heat pumps are expected later this year. Gradient says its All-Weather 120V model, which is designed to heat a room when the outside temperature drops down as low as -7˚F, will be available in the fall. (It already has a $4,997 mild-climate model available that operates down to 46˚F.)

Midea’s offering, which operates down to -13˚F, will be ready to order — and ship — this summer, according to David Leezer, retail AC research and development team leader at Midea.

Both manufacturers have started testing their cold-climate window heat pumps with renters in New York City public housing. As part of its efforts to decarbonize its buildings, the NYC Housing Authority contracted Gradient and Midea to install a combined 30,000 of their heat pumps under its Clean Heat for All Challenge. Now in its demonstration phase, the program has installed 74 units, providing the only heat sources to 24 public housing apartments this winter, at an average of three units per apartment. If all goes well, NYCHA expects to install another batch of 4,300 units in early 2025.

Will federal incentives help you buy a micro heat pump?

The Inflation Reduction Act provides two major incentives for home air-source heat pumps: a 30 percent tax credit of up to $2,000 and, for lower-income households, a forthcoming rebate of up to $8,000 to cover the cost of a heat pump. (For more details, check out Canary’s cheat sheet on the climate law’s consumer incentives.)

The good news is that both incentives are expected to eventually apply to micro heat pumps suited to cold climates. The bad news is that hammering out the qualification process could take a while.

For the rebate, the U.S. Department of Energy will first need to finalize a heating test procedure for the tech, which it refers to as room” heat pumps. Then Energy Star, the energy-efficiency labeling program administered by the U.S. Environmental Protection Agency, will establish criteria to certify room heat pumps as eligible for the rebate, the agencies told Canary Media.

For the tax credit, room heat pumps — like other air-source heat pumps — will have to meet specific energy-efficiency criteria, according to the IRS. This too depends on developing tests for room heat pumps’ heating capabilities, according to Christopher Dymond, senior product manager for residential HVAC at the Northwest Energy Efficiency Alliance. Room heat pumps are unlikely to be eligible for federal incentives until at least 2025.

As awareness grows, models get more cold-capable and these federal discounts kick in, micro heat pumps could prove to be the portable, climate-aligned heating solutions renters have been waiting for.

Note: This article has been updated to reflect new pricing information from Gradient.

Alison F. Takemura is staff writer at Canary Media. She reports on home electrification, building decarbonization strategies and the clean energy workforce.