What Is BTU?

People shopping for a new AC for the first time often have common questions. What is BTU? What does BTU stand for? BTU — or British Thermal Units — are the standard for measuring energy consumption for ACs.

This guide addresses everything you need to know about BTU to help you get efficient air conditioning, including:

• What BTU stands for and how it works
• Why BTU matters when choosing an air conditioner
• How to calculate the right BTU output for your space
• How to use BTU output to guide your AC’s maintenance schedule
• What to consider when upgrading to a new AC

If you still have questions about BTU after reading this guide, don't hesitate to reach out for more help.

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BTU stands for British Thermal Unit. It's a way of measuring how much energy your AC uses to remove heat from your home within an hour.

To some degree, it's a way to measure efficiency, much like a seasonal energy efficiency ratio (SEER) rating. Essentially, a BTU's meaning is how much an AC can cool, while SEER tells you how efficiently it does so.

BTU matters when you're shopping for an AC because you don't want to choose a unit that's too large or too small. Either way, you can run into serious problems.

When your BTU output is too high, you may experience problems such as:

• Short cycling. Your AC will run for a short period before cooling the central area down low enough to deactivate. However, because the home wasn't fully cooled, it turns back on again shortly after.
• Incomplete dehumidifying. When your AC short cycles, it can't fully dehumidify the air on hot, humid days.
• Temperature fluctuations.Room temperatures tend to fluctuate and vary more due to short cycling.
• Higher upfront cost. If you choose an oversized AC unit, you’ll be paying for more power than you can use.

Conversely, if the BTU output is too low, you have other problems, such as:

• Inadequate cooling. An AC that's not strong enough to cool the space you have will not be able to keep up with the demand.
• Increased energy usage. As the AC runs constantly, it uses more energy trying to cool a home.
• Increased wear and tear. Constant operation leads to additional wear and tear that can dramatically shorten your AC's lifespan.
• Moisture issues. Your AC dehumidifies as it runs, but without efficient cooling, it can't remove moisture from the air.

BTU can be a way to estimate the right size AC for your home, but it's not always the most accurate. Other factors, such as room size, how insulated your home is, household size, how many appliances are present, and your climate also affect it.

Most AC units will provide an output based on BTU. However, if you need to compare to watts, you can multiply the BTU by 3.41. To go from watts to BTU, divide the watts by 3.41 instead.

You can often find BTU calculators online to serve as a general guide or ask a professional to give you a more accurate estimate that considers all relevant factors.

Knowing your AC's BTU output can help you with maintenance and inefficiency issues to some degree. Your AC is capable of cooling the air inside about 15-25 degrees lower than the outside temperature. If you notice that it's unable to do so, it may reveal that there's a problem somewhere in your system that needs servicing or repair.

Poor performance, increased power bills, and an increasing need for repairs can all indicate that it's time to replace your AC. Or if you've done recent remodeling and you can no longer keep your home cool, you may need an AC with an increased BTU output to keep up with your evolving needs.

The honest, professional technicians at Advanced Air are ready to help you find the perfect unit for your new AC installation. With fast, convenient scheduling, we can get your new AC up and running ASAP.