With the dog days of summer rolling along, you may find yourself thinking more and more about the benefits of air conditioning.
Maybe you want to keep it simple and buy a window unit, or maybe the one you own isn’t working as well as it did last year. Perhaps the cost of AC in your upcoming electric bill is giving you anxiety.
In this post, we’ll try to get to the bottom of everything you’re wondering about air conditioning. There’s quite a bit to go over, so feel free to skip around to find the information you’re looking for.
Psst … want to learn more about your HVAC and other systems in your home? Check out our breakdown of your home’s electricity, plumbing, and HVAC.
What are the different types of air conditioners?
There are three main types of air conditioners. Though they have different setups, they all use refrigerants, coils, compressors, valves, and fans to collect heat from inside your home and move it outside.
- Window air conditioners (aka “window units” or “room air conditioners”): These fit in either a window frame or a space cut through an exterior wall (from the inside). The fans, coils, refrigerants, valves, and compressors are all packaged into the single unit.
- Central air conditioners: Central air conditioners have two units. One lives inside your home and the other sits outside. Fans blow cooled air through your home via ductwork and vents.
- Ductless air conditioners: Aka “ductless mini-split systems,” ductless air conditioners have a large outdoor unit, and several smaller, wall-mounted indoor units. Instead of using ductwork, the wall-mounted units blow cool air directly into the room.
What’s a BTU? And how many of them do I need?
Air conditioner sizes are measured in BTUs, which stands for “British Thermal Units.” Here’s the equation: 1 BTU = the amount of energy needed to change the temperature of 1 pound of water by 1-degree Fahrenheit. Huh? Don’t worry, you don’t need to memorize that! It’s basically a fancy way of measuring the cooling power of a particular air conditioning unit.
Knowing the BTU equation won’t help you figure out what size AC you need for a room, anyway. A good general room is to aim for 25 BTUs per square foot. For example, a 400-square-foot room would require an AC that puts out 10,000 BTUs. There are also some good calculators and charts out there to help you select the right size, like this one from The Home Depot, and this one from EnergyStar.gov.
Keep in mind, bigger isn’t always better. An air conditioner that is too big for a space can cause the unit to malfunction. It can also cool the air too quickly without removing enough humidity, leaving the room cold and clammy.
What is Energy Star? And what does it mean for my AC?
You know that little blue Energy Star sticker you see on some appliances? It has more meaning than you may think.
Energy Star is a government-backed program founded in 1992. It’s overseen by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), with the goal of equipping consumers with understandable and accurate information about the amount of energy different products use.
energy star According to EnergyStar.gov, nine out of 10 Americans recognize the blue energy star label. But what exactly does that little label mean?
The Energy Star label means an appliance met strict energy efficiency standards set by the EPA. Though requirements differ between products, passing the certification is no small feat. The appliances that receive the label have the lowest impact on the environment and save consumers the most money on energy bills.
Air conditioners with the Energy Star label are at least 10% more energy efficient than the minimum efficiency required by law. They also come with features such as energy saver mode and reminders to clean your filter.