How to Determine the BTU per Square Foot

If you purchase an air conditioner that does not produce enough BTUs for your space, your space will remain hot.

BTU, or British thermal units, along with joules and calories are the most common units used for measuring heat and cooling capacity. It is important to understand BTUs when buying home appliances such as air conditioners because, depending on the size of the room you are trying to cool, you will require certain BTU specifications. To calculate how many BTU's you need per square foot you first need to calculate the square footage of your space.

Instructions

1. Use a measuring tape to calculate the square footage of your space. For a square room, multiply the room's length by its width. For a triangular space, multiply the length by the width, and divide the product by two.

2. Look up the chart offered on the Energy Star website to find out the correct cooling capacity for your appliance. Select "Products" and then "Room Air Conditioners," followed by "Properly Sized" to locate the chart from their homepage.

3. Determine the correct cooling capacity for your space using the chart. Divide the number of BTUs required by the square footage of your space to determine the BTU per square foot.

References

• Engineering Toolbox: Units of Heat
• Energy Star: Properly Sized Room AC

Resources

• Read this Article in Spanish
• Energy Star: Energy Star Home