How Do You Know What Size Heater To Use In An Outdoor Spa?
It’s important to choose the right size heater for your outdoor spa. If you purchase one that’s too small, you’ll have a long wait while the heater warms up the water. Purchase one that is far too large, and your energy bills will be excessively high. The capacity of a water heater is measured in British thermal units (Btu). One Btu is the amount of heat that is required to raise one pound of water one degree Fahrenheit. Determine the capacity of your spa in gallons. For a rectangular spa, use the formula: Length x Width x Average Depth x 7.5. To find the volume of a circular spa, multiply Diameter x Diameter x Average Depth x 5.9. For an oval spa, use this formula: Long Diameter x Short Diameter x Average Depth x 5.9. Determine how long you are willing to wait for the spa to warm up 30 degrees. The less you are willing to wait, the larger the heater you are going to need. Use a heater input chart to determine the capacity of heater that you need. These charts are available online. Acc
