1. What is an AC Size Calculator?

Definition: This calculator converts air conditioner cooling capacity from BTU/hr to tons, which is the standard unit for AC sizing.

Purpose: It helps homeowners and HVAC professionals properly size air conditioning units for residential and commercial spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — AC size in tons
• \( BTU \) — Cooling capacity in British Thermal Units per hour

Explanation: One ton of cooling equals 12,000 BTU/hr, which originates from the amount of heat needed to melt one ton of ice in 24 hours.

3. Importance of Proper AC Sizing

Details: Correct AC sizing ensures energy efficiency, proper humidity control, and prevents short-cycling or inadequate cooling.

4. Using the Calculator

Tips: Enter the cooling capacity in BTU/hr (found on AC unit specifications or calculated from room size). The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is AC size measured in tons?
A: It's a historical measurement based on the cooling effect of melting one ton of ice in 24 hours (12,000 BTU/hr).

Q2: What's a typical BTU requirement for a room?
A: About 20 BTU per square foot, but this varies based on climate, insulation, and other factors.

Q3: What size AC do I need for a 1,500 sq ft home?
A: Approximately 2.5-3 tons (30,000-36,000 BTU), but a professional load calculation is recommended.

Q4: Can this calculator be used for heat pumps?
A: Yes, the same conversion applies to heat pump cooling capacity.

Q5: What happens if my AC is oversized?
A: Oversized units cycle on/off too frequently, reducing efficiency, dehumidification, and equipment lifespan.