For example the manual j calculation may say you need 25 000 btus for cooling.
Furnace btu for 1000 square feet.
And in cold climates multiply the square foot number by 30 40.
But your hvac dealer only has air conditioners that handle 24 000 or 30 000 btus.
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.
2 5 to 3 ton.
Furnaces are rated on their btus of energy consumption not their btus of energy output.
For example if you re trying to heat or cool 1 000 square feet you would multiply 1 000 by 20 and get 20 000 btus per hour.
90 000 to 100 000 btu hr.
2500 to 3500 sq ft.
3 5 to 4 ton.
But there are also rule of thumb estimations you can use to pick a furnace size for your home.
The british thermal unit or btu is an energy unit.
The above square footages do not include the area of the basement.
To learn how to adjust btu per square foot for special conditions scroll down.
It is approximately the energy needed to heat one pound of water by 1 degree fahrenheit.
Another quick and easy way to estimate the number of btu s required is with this helpful chart.
If your btu requirement is between sizes simply go with the bigger unit.
Choose the 30 000 btu unit to make sure your comfort needs are covered.
1 btu 1 055 joules 252 calories 0 293 watt hour or the energy released by burning one match.
80 000 to 90 000 btu hr.
3 to 3 5 ton.
For example if you re trying to heat 1000 square feet in a cold climate 30 000 40 000 btu s will add significant warm air to your home.
A more efficient furnace will output more btus of heat than a less efficient furnace with the same btu rating.
A standard that is used by heating and cooling equipment companies is to provide at least 25 to 30 btu of heat per square feet in the home for a moderate to warm climate.
Up to 2 5 ton.
2 000 square feet x 40 btus 80 000 btu output required thanks to the equation we know we need 80 000 btus of heat.
For cooler climates a very broad estimate of furnace sizing is to select one that generates 40 to.