How to Size a Room Air Conditioner

Have you ever wondered how to calculate the correct capacity when it comes to purchasing your new air conditioner? Do you feel that the air conditioner that you have previously purchased is over or undersize? It's not rocket science to find an energy-efficient air conditioner for your room. The following are some of the simple steps you can take to have a grasp on the minimum horsepower or BTU.


Find Out the dimension Of the Room

 First, noting down the approximate length (feet), width (feet), and right (feet) of the room and find out the volume of the room by timing the numbers up. For example, if the dimension of the room is 5ft (width), 20ft (length), and 5ft (tall), the volume of the room would be 500ft³ (5x20x5). 



                                                                                       Note Down The Dimension Of the room in wide(ft), tall(ft), and long(ft) 


Room Volume Times Magic Number


Theoretically, to calculate the minimum BTU (British Thermal Unit) simply times the room volume to 6 and you will get the BTU needed for your room without any external factors like human temperature, windows length, and kitchen location. For example, 500ft x 6 = 3,000 BTU/hour. That means that 72,000 BTU of energy is needed to cool the room per house. 

                                                                                btu calculation

                                                                           Calculate the minimum BTU needed by timing up the volume and the magic number, 6



Consider External Factor

 To compile the accurate numbers, it's also important to con other external factors such as the number of people, windows location, windows
height, and windows length. The following is a list of additional considerations.


Additional Sizing Considerations:


If the space faces due north or northeast or is heavily shaded, subtract 10 percent of the basic cooling capacity.  x 0.10 

If the space is extremely sunny (e.g. windows face west and southwest), add 10 percent of the basic cooling capacity.  x0.10 

If the space is poorly insulated,  add 15 percent of the basic cooling capacity.  x0.15 

If the space includes a working kitchen, increase cooling capacity by 4000 Btu/h.

If more than two people regularly (number of additional occupy the space, add 500 Btu/h people)  for each additional person. +500 

If the air conditioner will run only at night, subtract 30 percent of the basic cooling capacity. x0.30



SUMS up the numbers

 For example, if the aircond is regularly used by 2 people and the space includes a working kitchen, the final BTU needed will be 

3,000 BTU (minimum BTU needed) + ( 2X600) Regular User + 4,000 (Working kitchen in the room) = 8,200 BTU(approximately 1HP). 


 As a result, you should find an aircond within the range for the optimized cooling experience.  For your own convenience, you could use this heat load calculator from Daikin to size your room air conditioner.

                                                                     find the right aircond capacity


                                                                                  Find the correct horsepower if BTU unit is not applicable


Have you understood the method to size your air conditioner? Click to purchase aircond at best price.