HVAC Buying Guide: What to Know When You're Shopping

There are lots of heating and cooling technologies out there now, but one easily tops the list.

Mike De Socio Contributor
Mike De Socio is a CNET contributor who writes about energy, personal finance and climate change. His path in journalism has taken him through almost every part of the newsroom, earning awards along the way from the Boston Press Photographers Association and the Society of Professional Journalists. As an independent journalist, his work has also been published in Bloomberg, The Guardian, Fortune and beyond.
Expertise Energy, climate change and personal finance Credentials
  • Journalism awards from the Boston Press Photographers Association, the Society of Professional Journalists and Boston University
Mike De Socio
5 min read
A heat pump on the side of a wooden building.

Heat pumps, furnaces and air conditioners: Which is your best choice?

Devgnor/Getty Images

It's not glamorous, and most of the time it's hidden inside your walls, but it's hugely important to your home: HVAC.

Heating, ventilation and air conditioning systems can make or break the comfort of your home -- not to mention your budget. From furnaces to radiators and heat pumps, you're probably familiar with a lot of different heating and cooling options. Which one is best for your home?

It depends somewhat on where you live, but new technology is making HVAC more efficient (and potentially affordable) than ever before. Here's how to make sense of the big shifts in the industry, and decide which type of system is best for you.

How HVAC systems work

Most HVAC systems work on a simple equation that balances "distribution and return" of air throughout your home, according to Daniel Berry, chair of the HVAC program at the Fortis Institute in Scranton.

A standard gas furnace, for example, is calibrated to the size of your home and the climate you live in. It's designed to suck in ambient air from your home, boost it by 50 degrees Fahrenheit by burning natural gas (which is largely made of the fossil fuel methane) and then blow it through your house.

A central AC system works in a similar way, by condensing a refrigerant outside your house and cooling it off by blowing outside air over it. Then the refrigerant moves indoors, where it expands and gets colder. Indoor air is blown over the cold part of the air conditioner and distributed through your house's system of metal ducts. "You're going to have a tunnel effect of ductwork going through your house," Berry said.

Heat pumps work a lot like air conditioners. However, heat pumps can reverse the process and heat your house too, even in cold temperatures.

Air source heat pumps (which complete this process by transferring heat to or from the air outside your home) can heat or cool your whole home using air ducts or part of it with a smaller, wall-mounted unit called a mini split.

Ground-source heat pumps, also called geothermal heat pumps, exchange heat with the ground. Installation requires some trenching to bury some tubing and is more expensive, but the systems are more efficient.

Pros and cons of different HVAC systems

Each type of HVAC system has had its heyday, and you may have lived with various types of heat and cooling in homes of different ages. Here are the pros and cons of each type of system.

Hot-air gas furnace

Pros Cons
Works well even in extremely cold temperatures Requires extensive ductwork throughout your house
Can be an affordable type of heat when gas prices are low Burns fossil fuels, a source of planet-warming emissions

Central air conditioning

Pros Cons
Highly desirable for home comfort, which could boost home resale value Requires extensive ductwork throughout your house
Can run on clean, fossil-free energy A new central AC installation can be expensive and lead to higher energy bills

Air source heat pumps

Pros Cons
Provide both heating and cooling A new cooling system can be expensive and lead to higher electricity bills
Can run on clean, fossil-free energy Mini-split systems might require wall-mounted, interior units that some might find unsightly.
Use less electricity than other electric heating methods.

Ground source heat pumps

Pros Cons
Efficiency can save you a lot on energy bills One of the most expensive types of systems to install upfront
Can run on clean, fossil-free energy Require invasive construction of wells on your property
Provide both heating and cooling

How to choose an HVAC system?

Though many different types of HVAC are still available, Berry says there's really no competition these days. "If I was going to put a unit in, there's no question in my mind I would go with a heat pump," he said. "No if, ands or buts about it."

For existing homes, Berry recommends mini-split air source heat pumps, but for new construction it's best to go with a central heat pump system. Either way, this type of heat is the most efficient, cost-effective and comfortable option, Berry said. "You can't really beat those," he said.

How to choose an HVAC installer?

Finding an HVAC installer right now -- like finding any contractor -- can be challenging. Berry recommends getting at least three to four quotes and asking for a guaranteed installation timeline, that way you know you're getting the best deal.

To find a reputable installer, Berry advises you seek out established companies that have a good reputation among your neighbors. "You're going to want somebody who is dependable, reliable, who's been around for a while," he said. Don't be afraid to ask the installer for past customers who you can contact and ask about their experience, Berry recommends.

HVAC installation

In an ideal world, it takes about two weeks to install a new HVAC system, Berry said. Add in some buffer time for unexpected problems, and 30 days is a good estimate to work with.

But before you set a contractor loose on your home, make sure that estimated time frame is in your contract with the installer, Berry said. Reputable installers have an incentive to get the job done in a timely manner, so they can get on to the next job -- so if your contractor declines to give you a timeline, that might be a red flag, according to Berry.

Thin black tubing in an open trench.

Tubing for a ground source heat pump before it's buried.

SimplyCreativePhotography/Getty Images

HVAC maintenance and care

If you have any kind of system that involves ductwork (like a gas furnace or central AC), there's one piece of maintenance you can do yourself: changing the air filters.

Beyond that, Berry recommends calling in the professionals. Gas furnaces should be checked once a year, and Berry said service usually takes about an hour and a half. (If it takes any less, you might be getting ripped off.) Air source heat pumps should also be serviced once every one or two years, and don't forget to clean the filters on the mini-splits too. Proper maintenance can extend your HVAC system's life.

The same advice applies here: Make sure to work with a reputable, long-established HVAC company, even if it's a bit more expensive, Berry said.

Are there tax credits available?

Luckily, Berry's recommended HVAC technology -- air source heat pumps -- are also being incentivized by the government right now. A federal tax credit covers 30% of the project cost, up to $2,000.

There are other types of HVAC eligible for federal money: Check out the rebates for biomass stoves/boilers, central AC, gas furnaces and geothermal heat pumps.

Some states have additional credits available for heating systems. Check with your local power company for more details. 

Improve your home's energy efficiency

Heating systems are fundamentally designed to overcome the loss of heat that happens when air leaves your home through windows, doors and walls. 

Many homeowners now invest heavily in insulation and weather-sealing, which can significantly reduce the amount of heat your home loses. And in turn, that can allow you to get away with a smaller (and cheaper) heating system. New windows, doors, insulation and air sealing items also qualify for up to $1,200 in tax credits.

Berry recommends, however, that you don't go too small with your heating installation: No matter how insulated your home, you still want an HVAC system that can keep you toasty on the most frigid night.