How to Convert CFM to Tons of Refrigeration?

A general rule of thumb in HVAC is that 400 CFM (Cubic Feet per Minute) of airflow is required for 1 Ton of Refrigeration.

Thus, the conversion formula is:

Formula:

$\text{Tons} = \frac{\text{CFM}}{400}$

Example Calculations

Example 1: Convert 1200 CFM to Tons

$\text{Tons} = \frac{1200}{400} = 3 \text{ Tons}$

Example 2: Convert 800 CFM to Tons

$\text{Tons} = \frac{800}{400} = 2 \text{ Tons}$

Why is This Conversion Important?

Ensures Proper HVAC Sizing – Prevents over-sizing (waste of energy) or under-sizing (insufficient cooling).

Helps in Duct Design & Ventilation – Knowing the required CFM for cooling loads ensures efficient airflow distribution.

Useful for HVAC System Comparisons – Easily compare air conditioning systems based on airflow and tonnage.

Frequently Asked Questions (FAQs)

1. What does CFM stand for in HVAC?

CFM (Cubic Feet per Minute) measures airflow volume, indicating how much air an HVAC system moves per minute.

2. How do I determine the CFM needed for my space?

A common estimate is 20 CFM per square foot of room space, but factors like insulation, ceiling height, and occupancy can affect this.

3. Why is 400 CFM per Ton of Refrigeration used?

This is a standard rule in HVAC that assumes normal humidity levels and typical system efficiency. However, variations exist based on climate and system design.

4. Can this calculator be used for heating systems?

Yes! Though primarily used for cooling, CFM calculations also apply to heating and ventilation systems.

5. What happens if I have too much or too little CFM?

• Too much CFM = Overcooling, higher energy use, and excessive airflow noise.
• Too little CFM = Insufficient cooling, poor air circulation, and system inefficiency.