BTU Calculator for AC (India Cooling Load Guide)

Frequently Asked Questions (BTU Calculator & AC Sizing)

1. How many BTU do I need per square foot?

Typically, 20–30 BTU per square foot is required for residential spaces. However, this may increase based on climate, number of occupants, and sunlight exposure.

2. What size AC is required for a 12x12 room?

A 12x12 ft room (144 sq.ft) usually requires around 0.8 to 1 ton AC depending on heat load, number of people, and window area.

3. How do I convert BTU to tonnage?

1 ton of refrigeration equals 12,000 BTU per hour. You can divide total BTU by 12,000 to get required AC tonnage.

4. Does number of people affect AC size?

Yes, each person adds approximately 600 BTU heat load. More people in a room require higher AC capacity.

5. How does sunlight or glass area impact BTU calculation?

Rooms with large windows or direct sunlight gain extra heat. Typically, 150 BTU per sq.ft of glass area is added to the cooling load.

6. Is this BTU calculator accurate for Indian climate?

This calculator provides a close estimate for Indian conditions, but exact sizing may vary based on insulation, ceiling height, and outdoor temperature.

7. What happens if AC size is too small or too large?

An undersized AC will not cool properly, while an oversized AC may short cycle and increase electricity consumption.