1. What is the Air Duct Tonnage Calculation?

The air duct tonnage calculation estimates cooling capacity (in tons) from air flow rate in cubic feet per minute (CFM). This simple conversion helps HVAC professionals size equipment appropriately.

2. How Does the Calculator Work?

The calculator uses the basic equation:

Where:

• \( Tons \) — Cooling capacity in tons
• \( CFM \) — Air flow rate in cubic feet per minute

Explanation: This equation assumes 400 CFM per ton of cooling, which is a standard rule of thumb in HVAC design.

3. Importance of Tonnage Calculation

Details: Proper tonnage calculation ensures HVAC systems are correctly sized for the space they serve, preventing issues like short cycling or inadequate cooling.

4. Using the Calculator

Tips: Enter the air flow rate in CFM. The value must be greater than 0. The calculator will divide by 400 to determine the equivalent cooling capacity in tons.

5. Frequently Asked Questions (FAQ)

Q1: Why 400 CFM per ton?
A: This is a standard industry assumption based on typical air conditioning system performance, though actual requirements may vary slightly.

Q2: What if my system uses a different CFM/ton ratio?
A: Some high-efficiency systems may use 350 CFM/ton, while others may use 450. Adjust the divisor accordingly for your specific system.

Q3: How accurate is this calculation?
A: It provides a good estimate for standard systems, but exact capacity depends on factors like refrigerant type, coil design, and operating conditions.

Q4: Can I use this for heating calculations?
A: No, this is specifically for cooling capacity. Heating capacity calculations require different parameters.

Q5: What's the typical tonnage for a residential system?
A: Most homes use 1-5 tons of cooling, depending on size, insulation, and climate.