Expertises: Heating, ventilation, and air conditioning (HVAC), HVAC control system, Air conditioning, Humidiers, Dehumidifiers
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Converting kW to BTU/h is crucial when comparing the cooling or heating capacity of different air conditioners, especially across global markets using different units. For quick conversion, simply multiply the kW rating by 3,412. If you're evaluating efficiency using EER (Energy Efficiency Ratio), use the formula: kW × EER × 1,000. This helps estimate how much thermal energy an AC unit can transfer per hour. Whether you’re browsing models or sizing a system, tools like this kW-to-BTU/h calculator can simplify decisions—especially when used alongside detailed comparisons like those on Homesthetics’ best air conditioners guide.
Convert (kW) To BTU/hr Calculator
Defining BTU
BTUs, or British Thermal Units, is a measurement of energy that can be considered a unit of heat. One BTU is enough to raise the temperature of one pound of liquid water by a degree (Fahrenheit) at room temperature.
You may have seen BTU per hour as a unit of measurement in certain cooling units as well. This can be defined as the rate of energy transfer. The higher this value is, the more powerful the air conditioner will be. Consequently, the AC will also consume just as much power.
Defining kW
AC specifications often come with a wattage rating, specifying how much electricity the appliance consumes. “Watt” is a basic unit of power in the SI system, a.k.a the metric system. In more physics-based terminology, it is defined as the amount of power required to move a 1 kg object with an acceleration of 1 m/s2.
Or, 1 watt = 1 Joule of work done per second
A kW is short for kilowatts, and one kilowatt has 1,000 watts. That’s the unit you see on your electricity bill.
The Direct Equivalence Between kW And BTU
Every kilowatt is equivalent to 3,412 BTU per hour. And converting to BTU per hour from kW is a simple matter of multiplying the kW by 3,412.
For example, to calculate how many BTU/h there are in 2.5 kW, multiply the value by 3,412. The answer is 8,530 BTU/h.
How Energy Efficiency Rating Affects This Conversion
The previous section was a direct BTU conversion from kilowatts. But, when purchasing a new air conditioner, you may want to factor in the Energy Efficiency Rating. This will paint you a clearer picture of how much power the unit consumes.
Much like the previous conversion method, this method involves simple multiplication. You can know the BTUs of an AC by multiplying the kW rating with the EER rating and then multiplying the number by 1,000. Here’s the formula presented in a simplified manner:
BTU/h = kW x EER x 1,000
For example, if the AC has a kW rating of 3 and an EER rating of 12, the result is 36. Further multiplying it by 1,000 provides 3,600 kW as a result.
Tip
Some AC units have a SEER rating listed instead of an EER rating. In such cases, you can use the formula EER = 0.875 x SEER to convert between the two.
Summing Up
It’s simple to convert kW to BTU and can be done within seconds using the calculation methods listed above. And knowing how to do so is essential when purchasing a new air conditioner. A conversion calculator is also very handy in such situations.
The reason why there are two different units for cooling capacity is due to the different measurement systems. Both the International System of Units and United States Customary units have different units, such as kilograms for the former and pounds for the latter.
This can cause some confusion, but the conversion of units is rarely a complex affair.
