What is 1 HP? How many BTUs is 1 HP? Should I choose a 1 HP, 1.5 HP or 2 HP air conditioner?

When buying an air conditioner, you often see words like HP, BTU or horse and wonder what they mean? You also do not know what capacity air conditioner to buy to suit the area of ​​your room, to avoid wasting electricity. So let's find out in our following article!

What is HP?

Scottish scientist James Watt coined the term horsepower (HP) in the 18th century while working on improvements to Thomas Newcomen's steam engine. HP is a unit of mechanical power, a measure of the power with which a machine can perform a given amount of work. Based on a number of observations, Watt determined that a horse pedaling on a waterwheel could lift 550 pounds (249.4758 kg) of water 1 foot (0.348 m) in 1 second, so he defined horsepower as 550 ft-Ib/s.

1 HP = 9,000 BTU

1 HP = 0.7457 kW. Convert from HP to kW => number of HP x 0.7457

1 kW = 1.337 HP. Convert from kW to HP => number of kW x 1.337

For example, on the air conditioner is written 1.5 HP, equivalent to the number of kW is: 1.5 HP x 0.7457 = 1.12Kw. On the other hand, the power consumption of the air conditioner is 3.5 kW, which means the cooling capacity is 3.5 kW x 1.337 = 4.68 HP.

Due to geographical location, region, and living environment, the cooling capacity of air conditioners has different names. For example, the South calls air conditioners air conditioners and the cooling capacity is HP or horse power. The North calls the cooling capacity BTU.

Note, the conversion from BTU to W, kW is the conversion of cooling capacity, not the power consumption of the machine. To calculate the power consumption of the machine, we must convert from BTU to HP and from HP to kW.

How to calculate HP based on room volume

The cooling capacity of the air conditioner also depends on many factors such as construction materials, direct heat sources, number of people in the room and number of windows in the room. To choose the right capacity of the air conditioner, you should base it on the volume of the room (length x width x height).

Formula for calculating cooling capacity: HP = Room volume x 2/90

For example 

• Room size: 3 x 4 x 3.5m = 42 m3 => Cooling capacity is 42 x 2/90 = 0.93 => Need to choose air conditioner with cooling capacity of 1 HP.
• Room size: 4 x 5 x 3.5m = 70 m3 => Cooling capacity is 70 x 2/90 = 1.56 => Need to choose air conditioner with cooling capacity of 1.5 HP or 2 HP.
• Room size: 5 x 6 x 3.5m = 105 m3 => Cooling capacity is 105 x 2/90 = 2.33 => Need to choose air conditioner with cooling capacity of 2.5 HP

In case your house has windows and when using the air conditioner, there is often direct light shining in or the room with the air conditioner is connected to another room or has an exhaust fan, when buying an air conditioner, you should add 0.3-0.5 HP.

Some suggestions for installing air conditioners for different spaces

So, after reading this article, we hope you have got useful information and can find the right air conditioner.