A window heat pump is a window air conditioner that runs in reverse in winter, moving heat from outdoors into the room. Many window units with a heat setting do not do that. They warm the room with an electric heater coil, the same way a space heater does. This guide covers only units whose makers call them heat pumps or reverse cycle, and asks two questions of each: what the maker says about noise, and how cold it is outside before the heat pump stops.
The heating season changes how a window unit is used. In summer a window unit runs on hot afternoons. In winter it runs at night, with the house shut up and the street quiet. Our main window air conditioner guide ranks units for cooling. Our guide to U-shaped and saddle window units covers the designs that leave the window free. This one is about the winter.
Our picks are listed above, with full specifications for each.
Which window units are actually heat pumps
We checked each maker's own wording, because "heat" on a box can mean either kind:
- Gradient All-Weather 120V: sold as a "Window Heat Pump", and the brochure lists "AC & cold climate heat pump".
- GE AWGP08WWF and AWGP12WWF: the titles read "Smart Heat/Cool with Heat Pump".
- Midea MAW08HV1CWT and MAW12HV1CWT: the manual is titled "Inverter Window Heat Pump", and the EnergyGuide label says "Room Air Conditioner With Reverse Cycle".
- Soleus Air WS5-08HW, WS5-10HW and WS5-12HW saddle units: the manual says "Our units use the latest heat pump technology on the marketplace."
Others we read do not qualify. LG's heat and cool window units, such as the LW1223HRSM, list heating watts of 2,900 to 3,500 for 9,200 to 11,200 BTU of heat, about what a heater coil draws for that output, and LG does not call them heat pumps. Frigidaire's FHWH window units are sold as "supplemental heat", and we found no Frigidaire window heat pump. Midea's PortaSplit heat pump is listed on its European sites, not on Midea's US store. Friedrich's Kuhl+ heat pumps are real heat pumps, and the window-capable slide-out chassis models are covered below, but Friedrich publishes no decibel figure for them.
No maker here publishes a figure for heating mode. Where a mode is named, it is cooling. So every number below describes the unit cooling, or an unstated mode, and we compare only figures that share a label.
A figure for every fan speed:
- Gradient All-Weather 120V: 47 / 44 / 38 dB(A), high / medium / low. No mode, distance or test standard is stated.
A quiet setting named:
- GE AWGP08WWF: "40/59 dBA (Quiet Mode, Low Cool)".
- GE AWGP12WWF: "40/61 dBA (Quiet Mode, Low Cool)".
GE does not say which number belongs to which setting. On other GE units the Quiet Mode figure is the lowest on the sheet, so we read 40 as Quiet Mode. The second number is 2 dBA higher on the bigger unit.
A range with a stated distance:
- Soleus Air WS5-12HW-301 and WS5-10HW-301: 38 to 48 dB(A) indoors and 51 to 63 outdoors, "measured at a distance of 3.28 ft away from the front of the unit in cooling mode". No fan speed is named for either end.
One "as low as" figure:
- Midea MAW08HV1CWT and MAW12HV1CWT: "as low as 45 dBA", with no fan speed, mode or distance.
Laid side by side, the lowest numbers are close: 38 for Gradient on low, 38 at the bottom of Soleus Air's range, 40 for GE in Quiet Mode, 45 for Midea. But they describe different settings, and only Soleus Air says where the microphone was, so we do not rank them against each other. Why you cannot compare dB ratings across brands explains why a gap of a decibel or two between brands means little. The National Park Service notes that a 10 dB increase is heard as roughly a doubling of loudness. The 9 dBA between Gradient's low and high is the kind of gap you will hear when the fan steps up.
How cold each one heats, and what happens below that
This is where the units differ most, and where the makers are most specific.
- Gradient: heats at 9,000 BTU/hr from 47°F down to 17°F, 7,200 BTU/hr at 5°F and 7,026 BTU/hr at -13°F. Its efficiency falls as it gets colder, from 4.04 COP at 47°F to 1.59 at -13°F, but even at -13°F that figure is above 1, where an electric heater sits. The brochure lists operating temperatures from -13°F to 115°F.
- GE: 8,400 BTU of heat for the AWGP08WWF and 11,100 for the AWGP12WWF, with no outdoor temperature attached. The manual says the unit "is not designed to be used in 'HEAT' mode when the outdoor temp is below 5ºF."
- Soleus Air: 10,000 BTU/h of heat for the 10,000 and 12,000 BTU models and 8,400 for the 8,000, no outdoor temperature attached. The manual says heat pump technology "is the most efficient in heat mode above 30°F degrees", recommends auxiliary heat from central air or a space heater below that, and says the unit "is not designed for freezing outdoor conditions."
- Midea: no heating capacity published. The manual gives a heating range of 41°F to 75°F outdoors and says that below 41°F "the machine will shut off and display 'LO'." The product page says 40°F.
None of these five describes a backup electric heater. When the outdoor temperature drops past the limit, the room stops getting heat from the window. Friedrich is the exception: its Kuhl page says "230-volt models have backup electric heat that will activate when outside temperatures are too cold for efficient heat pump operation", and its submittal says its 115 V KHS10 heat pump has no supplemental heat and will not heat below 40°F. Kuhl units install in a window or through the wall, but Friedrich gives no decibel figure for any of them.
For a room where winter nights fall well below freezing, only Gradient states figures that cover them. For a room that needs heat in spring and fall, any of these will do the job, and Midea's unit, which was in stock, will do it for the lowest price.
What else you hear in a heated room at night
A winter bedroom is often the quietest room in the house. The windows are shut, nothing else is running, and in many places the street is quieter than in summer. A unit you would not notice on a July afternoon can be the loudest thing in the room at 2 a.m. Our quiet bedroom guide covers the rest of that room.
Fan speed steps. Every unit here has an Auto fan setting, and GE's manual says Auto raises the fan speed if the room needs more heating. For a steady sound at night, pick a fixed low speed or the quiet setting. GE says its Quiet mode works in Heat and sets "the lowest capacity and/or the lowest fan speed to achieve the best noise performance". Soleus Air's Quiet fan speed can be used in Heat mode too, and its sleep mode runs the fan on Quiet.
Energy saving modes that stop and start the fan. Soleus Air's manual says Energy Saver is the default startup mode and cycles the fan off and on with the compressor. GE's Eco mode does the same, and the fan may pulse to sample the room air. A fan that starts every few minutes is easier to notice in a silent room than one that runs steadily.
Lights and beeps. Soleus Air's display dims 10 seconds after sleep mode is set. GE's control panel lights turn off after a minute without activity. Midea's remote has an LED button that turns off both the display and the control panel beeps.
Frost on the outdoor coil. A heat pump working in cold air collects frost outside, and has to clear it. Gradient's page mentions "outdoor atomization of meltwater & condensate", and an internal condensate pump. No maker here publishes a figure for the sound of a defrost cycle, so we cannot tell you how it compares.
Fit, weight and the window
The designs differ in how much window they use. Gradient's indoor and outdoor halves straddle the sill and weigh 140 lb together, and need a window at least 26 inches wide and a wall 6.25 to 20 inches thick. Gradient's manual says "TWO-PERSON LIFT REQUIRED!" Soleus Air's saddle unit takes a window 24 to 48 inches wide with a 16 inch opening and a sill up to 12.5 inches. The GE units are standard window units for openings 24.5 to 36 inches wide and weigh 44.3 and 50.3 lb. Midea's units fit double hung windows 23.6 to 38.8 inches wide with a 13.8 inch opening, and the manual says to tilt the unit back about a quarter to half an inch toward the outside so water drains out.
A heat pump window unit also sits in the window all winter, so the seal around it matters for draughts as much as for noise. Gradient supplies sash bulb seals and a customizable window filler. Our page on Midea's air conditioner decibels lists the rest of Midea's range, including its U-shaped units, which do not heat.
When a window heat pump is the wrong answer
If the room needs heat on nights well below freezing and none of the units here suits your window, a ductless system is the permanent option. Our guide to the quietest mini-split for cold climates covers units rated for that, with the indoor head on the wall and the compressor outside. If you only need a little heat on a few cold evenings, a space heater with a published figure may be quieter and simpler; see the quietest space heater for a bedroom. A heater coil makes no compressor noise, but it uses more electricity for the same heat than a heat pump running within its range.
To set the decibel figures against everyday sounds, see our decibel chart.
How we chose
We looked for every window unit sold in the US that its maker calls a heat pump or reverse cycle: Gradient, GE, Midea, Soleus Air, LG, Frigidaire and Friedrich. We read each product page, spec table, brochure and owner's manual we could reach on October 6, 2026, and recorded each noise figure in the maker's own words, with the fan speed, mode and distance where the maker gives them. We recorded heating output only with the outdoor temperature the maker attaches, and the lowest outdoor temperature only where the maker states it. We grouped figures by label and did not rank across groups. LG and Frigidaire units with electric heat were left out, and Friedrich's Kuhl+ heat pumps were left out because Friedrich publishes no decibel figure for them. Prices are the makers' own, from the dates in the catalog; Gradient and SoleusAir West show none, and GE lists both of its heat pump units as no longer manufactured.
We did not measure any of these units, in heating mode or any other. Every figure here is the maker's own, and no maker publishes a figure for heating mode. Your room, your window, how well the unit is sealed in and how cold it gets outside will change what you hear and how warm the room gets.
