HomeExpertly
www.homeexpertly.comAir Conditioner BTU Calculator
Size a window or portable AC for one room — area, ceilings, sun, people and kitchen — using the EnergyStar rule of thumb, with the matching off-the-shelf unit, running cost, and a downloadable PDF.
Based on the DOE / EnergyStar room guideline of ~20 BTU per sq ft with adjustments. Great for room AC; a Manual J is what sizes central systems. For planning purposes only.
Room & Conditions
1
Room Size
ft
×
ft
ft
ppl
sq ft
Length × width. Edit to enter a known room area.
2
Room Conditions
Adds 600 BTU for each person over 2, and scales for ceilings above 8 ft. Set those in Room Size above.
3
Efficiency & Running Cost
EER
Higher EER = less power for the same cooling. Modern units are ~10-15.$/kWh
hr/day
BTU Estimate
Recommended AC Unit
—
Enter your room to begin
Calculated Load
—
Power Draw
—
Est. Monthly Cost
—
Cooling Load Estimate
Base load area x 20—
Ceiling adjustment—
Sun exposure—
Occupants over 2—
Kitchen—
Calculated load—
RECOMMENDED UNIT—
Room Area
—
Energy Use
—
Cost / Day
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Monthly Cost By Efficiency
Running cost for your unit, by EER rating
Efficiency Comparison — Your Unit
| EER | Power (W) | kWh / mo | Cost / mo |
|---|
For a 8,000 BTU unit at 8 hr/day. A higher EER pays back over the years.