A Homeowner’s Guide to Choosing the Right AC Unit

If you're thinking about investing in a home air conditioning system, here's an overview of the most popular options on the market.

Air conditioning can transform the comfort level of your home. But to get the most out of your investment, it’s important that you choose the right air conditioner for you.

Home Air Conditioning Explained

The term “air conditioning” refers to any system designed to control the temperature and humidity. In general, air conditioners can be grouped into either ducted or ductless systems. Ductless air conditioning uses small units scattered throughout the home, while ducted systems consist of a larger unit that distributes that cool air from a central location.

Ducted Air Conditioners

Central air conditioning systems are what most people mean when they talk about air conditioning systems. They can be an effective whole-house solution. If your home has warm or cold spots, however, you may benefit from a more targeted approach.

A new central air conditioning system will cost between $4,000 and $7,000. About 30 percent of that will go to the installer. So can you DIY a central air installation? That depends.

HVAC licensing requirements vary by state, and building permits vary by municipality. So while many homeowners will be permitted to work on their own heating, ventilation and cooling (HVAC) system, not all will be.

In addition, if your installation involves charging the air conditioning unit with refrigerant, you’ll need to earn an EPA 608 certification or bring in someone who has it to do the actual charging. You’ll also have to be comfortable handing the electric and ventilation requirements per your local building code. You might not have an inspector come out, but it still could become an issue when you sell the home. So while you can DIY a central air conditioning system, it’s really only a project suitable for the most advanced DIYers.

Heat pumps cause a great deal of confusion among homeowners. Essentially, a heat pump is an air conditioner that can operate in reverse. An air conditioner works by moving heat from your home’s interior to the outside. A heat pump does that as well, but it also moves heat from the outside in to heat the interior. From there, it can distribute the cooled (or heated) air in the same manner as central air conditioning.

Heat pumps cost about $5,000 to $8,000 to install. If you want to DIY, that will save up to $3,000, but you’ll encounter many of the same issues noted in the section above.

Geothermal heat pumps tap into the Earth itself to maintain a steady temperature. Just as a heat pump moves heat to or from the house to the outside air, a geothermal heat pump system uses underground pipes to move heat to or from the soil beneath the home.

Though environmentally friendly and affordable to operate, the steep cost to install them in existing homes can be daunting.  Depending on the layout of your property, it’s not unusual to see installation bills of $10,000 to $20,000. Geothermal systems are not forgiving of installation errors, so this is one job best left to the pros.

Ductless Air Conditioners

Ductless systems rely on pure power or multiple points of contact to cool an immediate area. There are several varieties of ductless air conditioners.

Window units are a great choice for homeowners on a budget, or for those with just a few small rooms to cool. As the name implies, window air conditioners perch on a window sill, drawing air in and blowing it back into the home. The rear of the unit projects away from the home to direct condensation out.

These units are available from $120 to $500, and can be taken with you when you move. If you live in an apartment building or multi-family home, be careful where you place them. They may trip overloaded electrical circuits and occasionally drip water outside. And if you live on the first floor, they can be a security issue; burglars could push it in to access your residence.

Portable units, much like window units, are designed to cool a single room at a time. Usually equipped with wheels, these need to be drained of water, like a dehumidifier. Expect to pay between $300 and $650 for a portable air conditioning unit.

Mini-split systems feature units strategically placed throughout a home to provide custom heating and cooling. Each contains a small heat pump that uses a mounted fan to cool the immediate area. Mini-splits have grown in popularity in recent years because of their high efficiency.

Expect to pay around $600 to $2,000 per unit, or $1,800 to $4,000 installed. (If you connect it to duct work, frequently done with ceiling models, the price will be higher.) As with other central air solutions, be sure to check local ordinances before tackling it as a DIY project.

Evaporative coolers, also known as “swamp coolers,” have some fundamental differences from traditional air conditioning. Instead of acting as a dehumidifier, they add moisture into the air to create a sense of cool dampness. They also push air into the home instead of recycling air that is already inside the house. Windows should be opened when running an evaporative cooler, and it should only be used in low-humidity climates.

Evaporative coolers are cheaper to purchase and much less expensive to operate than traditional air conditioning, although they do need regular maintenance and a supply of water. Portable units start at $100, while whole-house units run $1,200 to $2,000. Whole-house installation will likely run $600 to $1,000. This is a good task for a DIYer comfortable with duct work and basic electrical work.

Home Air Conditioner Maintenance

No matter what kind of air conditioner you have, there will be some maintenance necessary to keep it running smoothly. Almost all AC units have filters (even mini-splits and window units) that should be changed or washed as needed. Outdoor units should be inspected seasonally for damage and cleaned if needed.

Specialty air conditioning systems have different requirements. Evaporative cooling systems need a water source, and geothermal systems are extremely difficult to repair if there is an issue with the buried loop. Be sure to research carefully if you are considering one of those types of air conditioning systems.