Pick the right unit for every room
The law sets a minimum of 20 BTU per square foot. Use the chart to find the size, then choose the type that fits the window or wall you have.
Size chart
Each size covers rooms up to the square footage shown. Measure length × width in feet, or use the room calculator for exact numbers.
ENERGY STAR advises 10% more capacity for a sunny room and 4,000 BTU more for a kitchen.
- Up to 250 sq ft
- 5,000BTU
- Up to 300 sq ft
- 6,000BTU
- Up to 400 sq ft
- 8,000BTU
- Up to 500 sq ft
- 10,000BTU
- Up to 600 sq ft
- 12,000BTU
- Up to 700 sq ft
- 14,000BTU
- Up to 750 sq ft
- 15,000BTU
- Up to 900 sq ft
- 18,000BTU
- Up to 1,200 sq ft
- 24,000BTU
20 BTU per square foot, Admin. Code § 27-2030. Rooms over 1,200 sq ft need more than one unit.
Three kinds of unit
Start with what the room already has: a window, an existing wall sleeve, or neither.
- Window air conditionerUsually the cheapest option. Cools only. Installing a window unit
- Window heat pumpSits in the window like an AC but also heats in winter. Usually costs more, and qualifies for the NYSERDA incentive below. Installing a window heat pump
- Through the wall or PTACFits a sleeve in an outside wall and leaves the window free. Best when a sleeve already exists. Through the wall units and PTAC replacements
What to look for when you buy
- ENERGY STARCertified units use about 10% less energy, according to ENERGY STAR. That matters because the lease has to say who pays to run them.
- Inverter modelsThey adjust their speed instead of switching fully on and off, which usually makes them quieter and more efficient.
- U shaped window unitsThe window closes into a slot in the middle of the unit, so the window can still open partway.
- The plugCheck the voltage on the box before you buy. Larger units often need a 230 volt outlet, which means an electrician.
- WeightHeavier units need a sturdy bracket and two people to install, especially on upper floors.
Incentives that cut the cost
The biggest one right now is for owners willing to install window heat pumps instead of plain ACs. See what the law says about cost.
- Who qualifiesMultifamily building owners in New York State installing at least 10 window heat pumps.
- How it's paidNYSERDA pays the manufacturer, who usually takes it off your price. Capped at the full project cost, and $500,000 per project.
- Qualified makersMidea, Gradient, and Gree. Contact one for a quote and they submit the application for you.
- Affordable housingUnits for low and moderate income tenants get the higher amount, if the install doesn't raise their housing costs.
Source: NYSERDA Clean Heat for All: Room Heat Pump Program. Checked October 21, 2026.
NYSERDA window heat pump incentive
- Market rate apartment
- $1,500PER UNIT
- Low or moderate income
- $2,250PER UNIT
- Apply by
- June 30, 2027
Or until funding runs out.
Con Edison
Con Edison isn't offering a rebate on window air conditioners right now. Two programs are still worth a look.
- Smart Usage RewardsPays customers to cut electricity use during summer peaks.
- Multifamily programsIncentives for efficient equipment in apartment buildings, with more for affordable housing.
Source: Con Edison residential rebates and multifamily programs. Checked October 21, 2026.
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