Buying a new central air conditioner for your home is definitely a big deal. There are tons of options, brands, and models. Which should you choose? Does higher energy efficiency really matter? Is one kind of compressor better than another? How do you know if the warranty is a good one or not?
You've got questions, and we hope this central air conditioner buying guide can help.
Package (or packaged) units are the simplest. You buy one big cabinet and place it outside your house. That cabinet has the compressor, condenser coil, evaporator coil, fan motor, and everything else you need inside one single 'package'. It is connected to ductwork. Then, just turn it on, and it blows cool air into the ducts. You really don't have to do much else.
Simple!
Split systems are not so simple. Like a package unit, a split system central air conditioner will have an outside component. However, the other half of the split will be inside in an attic, crawlspace, or utility closet. The interior portion, the air handler, is connected to ductwork. The exterior bit, the condenser, is connected to the air handler via refrigerant lines and wiring.
Learn More: What Is A Package Air Conditioner?
Learn More: What Is A Split System Heat Pump?Â
Central Air Conditioner Fundamentals
What do we mean when we talk about a central air conditioner? Basically, we mean a system in which your home air is cooled at a central location before being dispersed back into the building via air ducts. That central location could be in the attic, a crawlspace, a utility closet, or even outside in a package air conditioner. From there, ducts and vents move the newly conditioned air to everywhere else. Centrality and ducts are the defining features of a central air conditioner. If you don't have ducts and rely on multiple condensers or air handlers, you don't have a central air conditioner. What you have might work, sure, but it's not central heating and air.
Package Unit vs Split System Central Air Conditioner
There are two main types of central air conditioner: package units and split systems.Package Units
Package (or packaged) units are the simplest. You buy one big cabinet and place it outside your house. That cabinet has the compressor, condenser coil, evaporator coil, fan motor, and everything else you need inside one single 'package'. It is connected to ductwork. Then, just turn it on, and it blows cool air into the ducts. You really don't have to do much else.
Simple!
Split Systems
Split systems are not so simple. Like a package unit, a split system central air conditioner will have an outside component. However, the other half of the split will be inside in an attic, crawlspace, or utility closet. The interior portion, the air handler, is connected to ductwork. The exterior bit, the condenser, is connected to the air handler via refrigerant lines and wiring.
Learn More: What Is A Package Air Conditioner?
Learn More: What Is A Split System Heat Pump?Â
Compressor: The Heart of the Central Air Conditioner
The compressor is the one component in an air conditioner condenser that will make the most difference in terms of efficiency and performance. The more sophisticated the compressor, the better the performance. Historically, most central air conditioner compressors have been single-stage. A single-stage compressor is simple. It turns on or off at full capacity. It does the job. Single-stage compressors are also cheap. Which is nice. However, if you want to save money, the best way to do that is with a two-stage or a variable-speed compressor. A two-stage compressor has two possible operating speeds. They operate at the lower setting as much as possible, then activate the second stage when necessary in hot weather. A variable-speed compressor takes two-stage technology to the next logical step. They feature multiple operating stages, and the ability to ramp performance up or down based on need.  They are highly efficient, but, of course, new technology is never as cheap as the old stuff.
Seasonal Energy Efficiency Ratio
Do you know the SEER of your current central air conditioner? No? We can't blame you too much. Seasonal Energy Efficiency Ratio (SEER) isn't exactly the most compelling topic. But, if you like money, it is very important. SEER is a measure of how efficiently any given air conditioner, central or otherwise, will operate over the summer cooling season. The higher the SEER, the lower your utility bill. Government efficiency standards step up every few years, so current central air conditioner units are often higher SEER than the best sellers from only a few years ago.Learn More: EER to SEER Conversion
Central Air Conditioner Warranty Standards
What kind of warranty should you expect with a central air conditioner? The standard anticipated lifespan of a typical central air conditioner is about 15 years. So, warranty protection that lasts ten years or so is fairly standard. Most respectable manufacturers will provide you with at least that much protection. Some might offer a lifetime warranty on the compressor too. These days, one important thing that you need to keep in mind with a central air conditioner warranty is registration. Most manufacturers require you to register your product warranty by a certain date after installation. Usually, you have 90 days, which is plenty of time to fill out a simple online form. Just make sure that you do it! Failing to register a warranty won't totally invalidate your warranty (in most cases), but it might cut ten years of coverage down to five. You want as much warranty coverage as possible, so register as soon as your new central air conditioner is up and running.Learn More:Â HVAC Warranty Stuff You Should Know