What Does BTU Mean: Know Your Heating and Cooling Systems

Are you looking for a new AC or furnace for your home? For sure, you will be overwhelmed with the abundance of choices that are available, each with the promise of being the best. Nonetheless, as a responsible buyer, you need to take time to evaluate the choices and narrow down the possibilities.

While there are many things that you should consider, one of the most important is their BTU. This is a technical specification that requires your understanding to see how one product will perform. If you do not know what does BTU mean, keep on reading and learn from the valuable insights that I will be sharing below.

What Does BTU Mean ?

In a nutshell, BTU means British Thermal Unit. This is a number that refers to the thermal or heating capacity of an appliance. It is a unit that is used for the measurement of energy. To be more technical, BTU is the amount of energy that is required to raise the temperature of one pound of water to one degree Fahrenheit at sea level.

It is important to note, however, that BTUs may work differently, depending on whether they are used in heaters or air-conditioning units. In heaters, BTU is the amount of heat that the unit is able to produce. In ACs, on the other hand, BTU is the amount of energy that the appliance produces for the purpose of removing heat in the air.

While BTU is still used in the UK today, in some cases, joule is used as a standard unit of measurement for the same thing. Approximately, a BTU is equivalent to 1,055 joules.

How Many BTUs Do You Need ?What Does BTU Mean

 Now that you know what does BTU mean, the next thing that you have to learn is the specific amount of BTU that you will need. The first thing that you have to do is to consider the size of the space that will be heated or cooled. You can always go straight to an appliance shop and ask the sellers for recommendations on the right BTU that you need. In the same way, you can also compute it on your own.

There is a formula for computation of the BTU, which will take into account the length and the width of the area that will be heated or cooled. The calculation can be quite confusing for some, but to give you a glimpse of the average BTU that will be needed base on a pre-defined floor area, here is a rough estimate:

150 square feet – 5,000 BTUs

300 square feet – 7,000 BTUs

400 square feet – 9,000 BTUs

1,000 square feet – 18,000 BTUs

1,200 square feet – 21,000 BTUs

1,600 square feet – 25,000 BTUs

1,900 square feet – 28,000 BTUs

2,700 square feet – 36,000 BTUs

It is important that you calculate the BTU before buying a heating or cooling equipment. If you choose BTU that is more or less than what you will need, you can suffer from some bad things.

For instance, let us say that you choose an AC with a BTU that is higher than what you need. It will lead to quick heating and cycling on and off. The latter will put too much stress on the compressor, which can speed up its wear.

On the other hand, if the BTU is less than what is required, regardless if it is a heater or air cooler, your comfort will most likely be compromised. The heating and cooling capacity will not be matched to your needs.

At the end of the day, if you are unsure on the BTU that is needed in your place, it is best to consult with an HVAC expert. They have the knowledge that will be vital in determining your specific requirements. With their help, you can be assured of your highest level of comfort while having an appliance that can deliver efficient performance.

Beyond Square Footage

 As it has been mentioned above, you need to compute the square footage first. If the area is rectangular, simply multiply the length and width, which are measured in feet. On the other hand, if the room is triangular, multiply the length and width, then divide it by two. You can use this figure as the basis for determining the right BTU for your needs.

However, it should be pointed out that square footage should not be the only basis. There are other external factors that should be given attention. For instance, you need to consider the external environment. Is it an enclosed room? Is it a room that gets plenty of sunlight throughout the day? Is there a second floor? In these cases, it is necessary to add at least 10% to the original BTU value that has been completed.

On the other hand, if the room has little sun exposure and if there is a lot of shade, you might want to reduce the BTU by as much as 10%. Nonetheless, keep in mind that it is always better to have a little more BTU than less than what you will need.

The number of people staying in the room can also have an impact on the necessary BTU. According to experts, if there will be more than two people at a time, an additional 600 BTU will be necessary.

Meanwhile, if you plan to install the cooling appliance in the kitchen, a place where it is often hot because of all the cooking, you will need to add as much as 4,000 BTU. This is because more effort will be required for cooling.


At this point, I hope that you already know what does BTU mean? It is a measurement of the heating and cooling capacity of a heater or air conditioning unit. It should be perfectly matched with your floor area, which will make it able to deliver the highest level of comfort. The next time you shop for an AC or furnace, make sure to not miss this technical specification.


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