What Is a BTU?

If you’ve ever shopped for a new air conditioner, heating system, or refrigerator, you’ve probably run across the term “BTU.” But what is a BTU? Are you wondering what’s my BTU rating? It can be confusing, but Sean Patrick HVAC is here to clear the air and explain everything you need to know about HVAC BTU.

Simply put, BTU stands for British Thermal Unit. In the energy sector, especially in HVAC, BTU is a primary unit of measurement. According to the U.S. Energy Information Administration (EIA), a single BTU is equivalent to the thermal energy of burning a match. Going further, BTU tells you how much energy it takes to raise the temperature of a pound of water by a single degree of Fahrenheit. Experts in the energy sector use the BTU rating to determine how much energy is used in various heating and cooling applications.

BTUs are used to measure the energy output of:

The BTU rating can help you when choosing appliances for your home, especially if temperature control is an important factor. Once you determine your energy needs, you can choose appliances with energy-saving features or choose larger appliances that have a high capacity to keep things cool. It might be helpful to use an online BTU calculator or a conversion app on your smartphone.

Try to calculate the size of an air conditioning unit by using BTU. According to Energy Star, a 5,000 BTU air conditioning unit can efficiently cool a space that measures 100×150 square feet. So, if you know the square footage of an interior space, you can find an air conditioning unit that efficiently meets your cooling needs.

Another way that BTU is useful is measuring the cost-effectiveness and efficiency of fuel. Different fuel sources like propane and natural gas are measured differently. Some are measured in gallons, cubic feet, or other units of measurement. However, the BTU rating is a way to equalize all of these different fuel sources. For example, 1 kilowatt hour of electricity is equal to about 3,412 BTU. Likewise, 1 cubic foot of natural gas is equal to about 1,036 BTU(2). You can use the BTU rating of fuel to create an energy efficient heating and cooling strategy for your home or office.

If you’re wondering what’s my BTU rating, there’s a simple formula that you can use. You need to multiply the weight of the fuel in question by the rise in temperature. This will give you the BTU rating. However, it’s not that simple. You should always rely on the expertise of industry professionals like Sean Patrick HVAC to help you make the right heating and cooling choice. We also factor in your home’s heat loss and overall energy efficiency.

It’s important to shop for the most optimal energy balance for your space. If the heating and cooling products you choose produce more BTUs than you need, then you’ll wind up wasting energy and spending more money in the long run. That’s why calculating the BTUs of your space ahead of time can save you time and money.

You can also read the BTU rating of your existing appliances. The BTU rating isn’t always listed, but you can check the product nameplate or label. This could be a sticker or metal plate that has all the important information for your appliance. You’ll find all sorts of useful information like power source, serial number, as well as heating and cooling capacity.

BTU ratings are generally thought of as “high” or “low.” In general, an installation with a high BTU rating can provide more heat to a given space. Smaller appliances that require less energy to operate will likely have a lower BTU rating. BTUs ratings are also measured in terms of input and output. Or in other words, potential and actual. The input value is the gross heating or cooling capacity at peak efficiency. Most systems don’t run at 100 peak capacity, so there’s an output value that closely mirrors actual results.

Yet, reading BTUs is not always that simple. You have to factor in the cost for the fuel and that’s where BTUs also work as a unit of measure. On the one hand, a low BTU rating might not heat as efficiently, but it will come at a cheaper cost. On the other hand, appliances like large air conditioners or heaters that carry high BTU ratings will cost more to operate due to the amount of energy it takes to run them.