HVAC systems aren’t terribly complicated. However, professionals usually confuse them to the point that selecting the right one seems impossible.

Have your eyes ever glazed over as a salesman droned on and on about esoteric features that don’t even make sense to you? Below is a crash course on HVAC systems, so you can easily make the right choice the next time you want to upgrade your HVAC.

Residential HVAC InstallationFirst of all, HVAC stands for Heating, Ventilating and Air Conditioning. A HVAC system installed in your home is a comprehensive solution for indoor temperature control. It allows you to increase or decrease the temperature as you see fit.

Most central heating systems are gas-fueled. They consist of a furnace that pulls air in, heats it, and recirculates it through the house using air ducts. If your home doesn’t have pre-installed ductwork, you can either install it, or buy a ductless air conditioner.

ACs work in pretty much the same way, but in reverse. Air is taken in, cooled, and then recirculated via air ducts. It’s a bit more complicated than that, but this explanation should suffice for the purposes of this article.

What type of unit should you get? Let’s first talk about the furnace.

You should start by thinking about efficiency. Most new furnaces are over 90% effective, but some people prefer older ones since they are simpler in design. You should also check whether your energy company offers rebates for installing more efficient units.

If you have old ductwork, have it inspected for asbestos. It’s hazardous for your health, so make sure you remove it.

There are three main types of furnaces: single-stage, two-stage and modulating furnaces. Most contractors are on the fence about modulating furnaces because of their relative newness, so you may want to hold off on buying one at the moment.

Single-stage furnaces have only two settings: on and off. This reduces their efficiency exponentially. You’ll also have to sacrifice some comfort since they don’t offer temperature adjustment at all.

Two-stage furnaces can be set on high or low. You still don’t have complete control over the temperature, but at least you can make some adjustments if you think it’s too hot. They’re also more efficient than single-stage ones.

On to air conditioning: Look for the same things when searching for a new AC: efficiency, reliability, and capacity.

AC technology has been getting better over the years. AC efficiency (denoted by SEER) has tripled over the past two decades – although the most efficient models are also the most expensive. Most energy companies will give you a rebate if you buy a more efficient AC, so keep that in mind.

The type of AC you’ll require will vary depending on the size and insulation of your house. Talking to your HVAC technician will help you establish exactly what you need.

So, there you have it: a layman’s guide to choosing a HVAC system. Keep in mind your HVAC technician will know a lot more than you, so don’t rely solely on the information you get from this article. Remember, there are a lot of details you still need to learn before making your choice of the best HVAC system for your home.