Gas Furnace Btu For Square Footage

Calculate how many btus you need to heat a room or even a house with a wood burning pellet or gas fireplace insert or stove.

Gas furnace btu for square footage. 1 watt is approximately 3 412 btu per hour. For this example using an 80 efficient furnace the 1900 square foot home above would require a 90 000 btu input furnace that produces 72 000 btu s of heating which is close enough to the 76 000 btu s required using the climate heating factor. For example if a furnace is rated at 100 000 btus and is 80 efficient then the heat output will be 80 000 btus 100 000 x 8. We included an example for you below.

For this example using an 80 efficient furnace the 1900 square foot home above would require a 90 000 btu input furnace that produces 72 000 btu s of heating which is close enough to the 76 000 btu s required using the climate heating factor. Thanks to the equation we know we need 80 000 btus of heat. The actual production of heat called the output btu will be the main factor in deciding which heating unit is right for your. Furnaces are rated on their btus of energy consumption not their btus of energy output.

A high efficiency furnace generating 100 000 british thermal units btu with a 93 percent rating will produce significantly. What is a btu. For example a furnace with an input btu can have an efficiency of 80. At 40 to 45 btus per square foot you d need a 100 000 to 112 500 btu.

But before we buy an 80 000 btu furnace there s furnace efficiency to consider as well. 2 000 square feet x 40 btus 80 000 btu output required. A more efficient furnace will output more btus of heat than a less efficient furnace with the same btu rating. Another variable in determining your energy needs is space both in terms of square footage and cubic footage.

Average square and cubic footage. Take your home s square footage and multiply it against the btus your climate requires. For example in zone 3 to 4 which typically requires 40 45 btu per square feet you can determine that a 2 500 square foot home would need a 100 000 to 112 000 btu furnace. For cooler climates a very broad estimate of furnace sizing is to select one that generates 40 to 45 btus per square foot.

It is approximately the energy needed to heat one pound of water by 1 degree fahrenheit. 1 btu 1 055 joules 252 calories 0 293 watt hour or the energy released by burning one match. That means the furnace will produce 80 000 btu of heat. If that same furnace has an efficiency of 95 the furnace will produce 95 000 btu of heat.