Once you have the total square footage just multiply that number by 20 to find how many btus per hour you d need to heat or cool the space.
Btu per square feet cooling.
For example a room that is 20 feet long by 20 feet wide would be 20 x 20 400 square feet.
Btus stand for british thermal units and refer to the amount of energy your air conditioner is using per hour.
How to find how many btus your furnace should be.
Assuming the minimum cooling capacity of 400 square feet per ton for your hvac unit a 1600 square foot home will require 4 0 tons of air conditioning to cool.
The smaller the volume the fewer btus are required to cool or heat.
Window air conditioners typically have a cooling capacity ranging from 5 000 to 12 500 british thermal units btu hr.
We often refer to the british thermal unit as a btu but the rating is actually the btus per hour or btu h.
To learn how to adjust btu per square foot for special conditions scroll down.
Your hvac unit will need to remove about 4 0 x 12 000 btus or 48 000 btus per hour to keep your home cool.
The middle part of the country zone 3 and 4 require between 40 45 btu per square foot while the northern areas of zone 5 need up to 60 btus per square foot.
As a rule of thumb an air conditioner needs 20 btu for each square foot of.
However volume is a more accurate measurement than area for determining btu usage because ceiling height is factored into the equation.
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.
1 btu is the equivalent of 1 055 joules or 293 watts.
1 btu is the energy needed to heat 1 pound of water by 1 fahrenheit.
In the simplest terms the colder or warmer the outside air the more energy you ll need to move the internal temperature of a building.
Each three dimensional cubic square foot of space will require a certain amount of btu usage to cool heat accordingly.
If there are more rooms such as closets simply do the same and add them to the total.
Btu sizing chart for mini split hvac units.
This is done by calculating your square footage.
Air conditioners are sized by the number of btus they put out.