Keystone · Model KSTAT08-1HD
8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat
A through-the-wall air conditioner rated at 8,000 BTU for rooms up to 350 sq ft. It heats in winter too and installs in a wall sleeve.
$569.99
Live price at SylvanePrice checked Oct 27, 2026
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Will it cool your room?
This unit's cooling matches a 350 sq ft room. Set your room size to check the fit for your space.
At a glance
Best for replacing a through-the-wall unit in an existing wall sleeve.
Performance
- Cooling capacity
- 8,000 BTU · 2.3 kW
- Power while cooling
- 825 W (7.8 A at 115 V), about $0.15 an hour
- Heating capacity
- 4,200 BTU
- Heat source
- Electric coil
- Power at rated heat
- 1,380 W, about $0.25 an hour
- Room coverage
- up to 350 sq ft
- Energy Star
- Not published
- CEER
- Not published
- Annual energy (cooling)
- Not published
Noise, size & features
- Model number
- KSTAT08-1HD
- Indoor noise
- 51.8 dB(A)about as loud as a refrigerator
- Outdoor noise
- Not published
- Indoor unit
- 24.2 x 14.5 x 20.3 in
- Outdoor unit
- None
- Refrigerant
- R-32
- Wi-Fi / app
- Not published
- Outdoor unit needed
- No
- Power supply
- 115 V, NEMA 5-15P plug
- Wall sleeve
- Fits 25½ to 27 in. sleeves
- Warranty
- 1-Year Warranty
Heating capacity, heating power, supply voltage, plug, cooling power, cooling current, refrigerant and warranty are from Sylvane's published specifications for this exact configuration, checked Oct 18, 2026.
Power while cooling: From the maximum cooling draw its retailer lists for this exact model. An hour's cost is at that draw and the US average electricity price of 18.44¢/kWh (U.S. Energy Information Administration, Electric Power Monthly Table 5.6.A (residential average, May 2026)). The compressor cycles once the room is cool, so most hours cost less.
Hourly heating cost: At the rated heating output and the US average electricity price of 18.44¢/kWh (U.S. Energy Information Administration, Electric Power Monthly Table 5.6.A (residential average, May 2026)). A thermostat cycles the heat, so most hours cost less. A heat pump's output and advantage shrink as it gets colder outside, and one with an electric back-up heater draws far more while that runs.
Will it fit your wall sleeve?
Keystone's installation manual lists the existing sleeves it fits, from Frigidaire, GE/Hotpoint, Whirlpool, Fedders/Emerson, Sears/Kenmore, Carrier and Friedrich (25½ to 27 inches wide), and the old rear grille is replaced by the one in the kit. Keystone's own sleeve for a new installation is the KSTSLV1, sold as a 26-inch sleeve (its spec sheet gives 25½ x 15¼ x 17½ in.), for walls up to 17¾ inches thick. Source: Keystone installation manual
Every through-the-wall AC and PTAC by the sleeve it fitsWhat is good
- At 51.8 dB(A) it is quieter than 22 of the 24 other through-the-wall units we list that publish a noise figure.
- Uses R-32 (GWP 675), the low-GWP class new US residential equipment moved to.
Installation & the rules that apply
This is a through-the-wall air conditioner. It sits in a sleeve built into an exterior wall, so the window-unit mounting and bracket rules do not apply to it. Swapping it into an existing sleeve is a like-for-like replacement; cutting a new opening changes the building's exterior wall, which usually needs a building permit and, in a condo, co-op or historic building, approval first.
Slides into a wall sleeve
R-32
Common questions about the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat
- How loud is the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat?
- 51.8 dB(A) indoors, about as loud as a refrigerator.
- How many watts does the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat use?
- It draws 825 watts (7.8 amps at 115 V) while cooling at full power, per its retailer's specification for this exact model. At the US average electricity price that is about $0.15 an hour; once the room is cool the compressor cycles, so most hours cost less.
- What size room does the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat cool?
- It is rated to cool a room up to 350 sq ft (8,000 BTU · 2.3 kW).
- Do I need a professional to install the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat?
- Not to replace a unit, but usually yes for a new opening. Sliding it into an existing wall sleeve it fits is a job you can do yourself (it is heavy, so plan on two people), with no refrigerant work. A new installation means cutting an opening through an exterior wall and fitting a sleeve, which is contractor work and usually needs a building permit.
- Does the Keystone 8,000 BTU Through-the-Wall Air Conditioner - Cool/Heat heat as well as cool?
- Yes. It heats with an electric coil, rated 4,200 BTU of heating output on 1,380 watts. At its rated heat it costs about $0.25 an hour at the US average electricity price.
Buying guides for a through-the-wall unit like this
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