When the temperatures rise and your home begins to feel like an oven, it's time to switch on the AC. But if you haven't purchased one yet or have noticed that your current unit just isn't getting the job done anymore, you'll need to consider buying an AC unit that will work. And when it comes to buying AC units, one of the single most important numbers you'll need to remember is certainly the BTU. It's displayed prominently on air conditioner packaging, and most people are at least familiar with the term. But understanding more about it is important since it will dictate just how effective and efficient your AC system is.
BTU stands for British Thermal Unit, and it's a measurement of energy roughly equal to around 1055 Joules. It's also the standard unit used to measure power in air conditioning units. The higher the BTU level, the more powerful the unit and the more capable it is of cooling larger spaces.
Buying the right AC unit is important, and it can get confusing when you start looking into BTU levels on a system when you buy. In most instances, the rough guidelines say that for every 500 square feet of space in your home, you need 12,000 BTU. So a 1,000 square foot apartment would need a 24,000 BTU AC unit. However, areas with much hotter climates could need more than this average, as could homes with poor insulation. Your best bet is to use the 12,000 BTU per 500 square feet average and then expand on it based on your situation. It's always better to buy a unit with a bit more power than one that won't work.
You can also purchase multiple AC units, and in some cases you'll have to. Window units aren't that effective at cooling multiple rooms, so you'll need to place several if you have a large home. Two story homes will require a multiple unit approach, as well.
It's worth noting that BTUs aren't really the main thing that will be used to denote the power of a central air conditioning system. Large HVAC units are usually referred to by their tonnage. A one ton unit doesn't weigh one ton - the number refers to an old method of cooling that relied on large ice blocks. For every one ton of ice used in a day, the home was said to take that many tons to cool. Today, every ton that a unit can handle is equivalent to around 12,000 BTUs. In other words, for every 500 square feet in your home you'll need one ton of cooling power.
Again, it's important to consider your situation when you buy any AC unit. The BTU level will certainly be a good guide to help you figure out what kind of unit you need, but consider your circumstances including your home's insulation level, your area's temperature, and more. With the right steps you can figure out what kind of AC unit you need with ease. BTUs are just the basic blueprint you need to get started.