How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ed Johnson Your Own Question
Ed Johnson
Ed Johnson, Handyman
Category: Home Improvement
Satisfied Customers: 10760
Experience:  Home owner and handyman, have rebuilt house and car engines, and a train in S. America
Type Your Home Improvement Question Here...
Ed Johnson is online now
A new question is answered every 9 seconds

How do I figure out how many BTUs I need to cool 4000 sq. Ft.

Customer Question

How do I figure out how many BTUs I need to cool 4000 sq. Ft.?
Submitted: 11 years ago.
Category: Home Improvement
Expert:  Ed Johnson replied 11 years ago.

This will depend on if there is a second floor or not, and if it is occupied.

However, in general, 4,000 square feet will take between 48,000 and 60,000 BTU's.

You can check this handy reference guide for cooling requirements:

Commercial Airconditioners, including those designed for large homes, are measured in tons. 1 ton is equivalent ot about 12,000 BTU's. it is not uncommon to have a 3 to 5 ton AC for a large home.

Generally, an Airconditioner needs about 20 BTU's per square foot of living space. Add 5% to cover usage.

If you want a more accurate determination, you can send for a calculation form from:

The Association of Home Appliance, Manufacturers 20 North Wacker Drive, Chicago, Illinois 60606

Ask for the cooling load estimation form. It will include the formulas and is very easy to understand how to put in the information.