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How Many BTU for 800 Square Feet
800 square feet needs about 20,000 BTU/h (1.67 tons) to cool and 28,000 BTU/h to heat a standard insulated space.
How Many BTU for 800 Square Feet
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About How Many BTU for 800 Square Feet
For 800 square feet of standard insulated space, cooling needs about 20,000 BTU/h, using 25 BTU/h per square foot. That is about 1.67 tons, and 800 square feet is typically a one or two bedroom apartment. At this size window units stop being the practical answer for the whole space, and the realistic options are a single zone mini-split for an open plan layout, a multi zone mini-split with a head in each main room, or a small central system. This page loads with 800 square feet already entered so you can adjust the space type, ceiling height and sunlight. Mini-splits are commonly sold at 18,000 and 24,000 BTU, so 20,000 sits between two sizes. For a well shaded apartment the 18,000 unit is usually enough. For a top floor flat under a roof, or one with large west facing windows, the larger size is safer. If the apartment has separate bedrooms, a multi zone system lets each room run independently, which is both more comfortable and cheaper to run than cooling every room to suit the warmest one. For heating, 800 square feet needs about 28,000 BTU/h, around 8 kilowatts. For a larger space see How Many BTU for 1000 Square Feet, or for a smaller one How Many BTU for 600 Square Feet.
How to use How Many BTU for 800 Square Feet
Enter room area in m² or ft²
Set ceiling height, sunlight exposure, and number of occupants
See recommended BTU, kW, and AC unit type
Frequently Asked Questions
How many BTU do I need for 800 square feet?
About 20,000 BTU/h for cooling a standard insulated space, about 1.67 tons. A top floor apartment or one with strong afternoon sun needs more.
Is 18,000 or 24,000 BTU better for 800 square feet?
An 18,000 BTU unit suits a well shaded apartment, and 24,000 BTU suits a sunny or top floor one. The calculator above shows the figure with your sunlight and ceiling settings.
Should an 800 square foot apartment have one unit or several?
If the bedrooms have doors that are closed at night, several. A multi zone mini-split with a head per room conditions each space separately and avoids overcooling the living room to reach the bedrooms.
How many BTU to heat 800 square feet?
About 28,000 BTU/h for a standard insulated space, roughly 8 kilowatts. A larger heat pump or a dedicated furnace circuit handles this.
How many tons of AC for 800 square feet?
About 1.67 tons. Central systems come in half ton steps, so 1.5 or 2 tons depending on insulation and sun.