Best new furnace

What features should I look for and what efficiency makes sense?

I’m trying to decide on the best new furnace for my home. I need a forced air gas furnace to replace a Goodman furnace that has an incredibly noisy fan. It still works but now that winter is wrapping up I think it’s time to replace it. What features should I be looking for in a furnace and should I go for mid- or high-efficiency?

Answer from Green Energy Efficient Homes

The best new furnace for everyone isn’t a furnace at all, it’s a heat pump. I can no longer in good conscience recommend anyone purchase a furnace, given the climate emergency and the need for all of us to reduce our carbon footprint as quickly and as much as possible. See my entire new section on heat pumps for lots of helpful information on why heat pumps really are not only the more environmentally friendly choice, but the more cost effective choice in the long run.

So let’s rephrase the question as: What is the best new forced air heating solution for me?

I would advise you to start your search for the best new heating source by looking for the best HVAC installer in your area. There is a great deal of fuss on the internet about the reputation of this or that HVAC manufacturer and there is no shortage of negative reviews for just about all of them, while there are few positive reviews for any of them. There are two reasons why you’ll hear every homeowner complaining, and almost no one claiming they have the best new furnace:

1. People write reviews when they’re upset about how their product is working (or when it stops working). So we see lots of negative reviews and few positive ones.
2. Most HVAC problems are the result of faulty sizing, installation or servicing, not faulty or shoddy manufacturing. If you buy your HVAC equipment from the cheapest HVAC contractor, he is finding his profit by hiring cheaper labor or by rushing the install.

How do you find a good HVAC installer? First of all, keep an eye out for HVAC trucks in your neighborhood. If one is parked at a neighbor’s, visit that neighbor a few days later to ask how the install went and why they choose that installer. Ask your friends and relatives who they used and whether they were happy. Search on sites like homestars.com to find HVAC contractors in your area who have a good rating. (Read all their reviews though – and watch out for signs that a contractor is spamming reviews.)

Phone up prospective HVAC installers and ask them what products they offer and why you should consider using them. Ask them what they do to figure out the best new furnace or heat pump for your needs. Ask them what they consider the best new furnace or heat pump brands, and run a few brand names by them to get their opinion. Watch out for installers who bad mouth all the brands they don’t carry. Also ask any HVAC installer you are considering what awards or recognition they have received over the years, and follow up to verify the awards are legit. Ask any you are considering to provide you with at least three references, and phone those references.

Speaking of heat pumps, one great question to ask, even if you are considering buying a furnace rather than a heat pump, is whether a heat pump might be a better option for you. If your HVAC salesperson suggests that heat pumps are not up to the job, that they are super expensive to operate, or that they can’t heat your home in cold weather – find another HVAC company. The salesperson either hasn’t been keeping up with developments in heat pump technology, or just doesn’t want to offer a heat pump because it’s easy for them to keep installing what they’re already used to installing (or what they have too much stock of).

Find out if the installer offers service contracts for the equipment they install, and how much the contract costs per year both during the warranty period and afterwards. The best new furnace or heat pump is one that doesn’t cost you a cent in unplanned expense in its first twenty years of operation – all you pay is the up front cost, and the annual maintenance and service fee.

Now that you’ve found an installer…

I really believe you should search for a good installer first, then look for the right heating equipment within the product lines they offer. Don’t be surprised if they don’t sell or install the brand you want. After all, they specialize in one or two brands for a reason: they trust those brands and know them well. You wouldn’t want your Dodge dealer to service your Toyota, would you?

Things to look out for when buying the best new furnace include getting the right BTU output, as high an efficiency ration (ER) as you can afford, and additional features such as a variable speed, DC blower motor (more energy efficient and quieter), high quality air filter, and a decent humidifier. You should also decide up front, before upgrading to the best new furnace, whether you will soon want to upgrade your central air conditioner (or install a new one if you don’t already own one). You can get higher efficiency on both heating and air conditioning if you buy both your furnace and AC unit from the same manufacturer, since in some cases you can get a high SEER heat pump along with the furnace, that will heat the house when temperatures are mild outside (leaving the hard work on colder days to the furnace), and cool your house efficiently in hot weather.

In fact, if you need to upgrade your air conditioner as well – or if you are planning on upgrading it within the next five years, your best bet is to go straight to a heat pump, which can both heat and cool your home. It won’t look much different from a regular whole house air conditioner, but does double duty cooling in summer and heating in winter, all without emitting any CO2!

BTU output: One of the things you should watch for when an HVAC installer comes to your home to do a quote, is how thorough a job they do of sizing your new furnace or heat pump. If they just eyeball it and tell you in five minutes that you need an 80,000 BTU unit, don’t use them! You could wind up with a furnace or heat pump that short-cycles (short bursts of heating that rapidly warm the place) or one that can never bring you up to a comfort level. The installer needs to do a heat load calculation, to figure out how much space you have to heat, how much heat will escape through walls, ceiling, and windows/doors, and therefore what BTU capacity you will need. When we had contractors estimate our new furnace in 1997 I had several quote me a price on a 60,000 or 75,000 BTU furnace without even walking around my house. The contractor I eventually selected told me a 40,000 BTU furnace was adequate – based on my modest heating needs (a thermostat setting a few degrees lower than most people use, and plans to continually upgrade insulation and windows). He said there might be a few days each winter when it takes the furnace a little longer to bring the house up from the programmable thermostat night-time temperature to the comfort temperature, but I would get better overall efficiency (and a lower installation cost) with the lower BTU furnace.

Efficiency Ratio (ER): There’s not a lot of difference in efficiency, for furnaces in 2023, between the least and most efficient. The least efficient tend to be in the 92% efficiency range – meaning 92% of the energy in the natural gas is converted to heat that heats your home. The most efficient furnace achieves efficiency of around 98%. Realistically, a 6% difference in natural gas consumption is not going to make a difference for the planet or your pocketbook. Is it worth paying an extra $2000 for a 6% gain? That might save you (assuming a $1500 yearly heating bill) a total of $90 a year, or $1800 over the expected 20 year lifetime of the furnace. The climate impact is also not that big; there are probably more impactful ways to spend that extra $2000 if you’re trying to do the right thing for the planet.

Speaking of efficiency, here’s another area where heat pumps excel. Heat pumps don’t produce heat; they extract heat from the cold outside air, and pump that heat into the warm indoor air. Heat pump efficiency is measured by something known as COP or Coefficient of Performance. The COP reflects the units of heat energy produced, per unit of electrical energy consumed. It’s fairly typical for heat pumps to have a COP of 4.5 or 5.0 when the outdoor temperature is mild, dropping down towards a COP of 1.0 as the temperature drops into the bitterly cold category (think 0F or -17C). A COP of 4.5 means you’re getting 4.5 units of heat energy for every unit of electrical energy you’re putting in. A COP of 1.0 means the heat pump is about as efficient as an electric heater.

Another reason to opt for a heat pump: natural gas prices will likly continue rising over the next several years as more and more jurisdictions introduce or increase carbon pricing, to get people to move away from natural gas towards renewable heating souces. While natural gas prices have been fairly low in North America in the last few years, this will surely change as pressure grows on governments to take action on climate change. (It is already happening in Canada, where in provinces that don’t have their own carbon pricing scheme, we pay something like $180 per tonne of CO2 emissions, climbing to closer to $300 per tonne by 2030.) Why buy yesterday’s technology and commit yourself to paying ever more carbon tax (and contributing ever more CO2 to an already overburdened climate) when you can go straight to a modern heat pump?

Blower motor: One of the ways high-efficiency furnaces and heat pumps beat out their mid-efficiency cousins is by using a variable speed DC motor. Remember that your furnace or heat pump uses electricity to blow the air around, and a DC motor tends to be more efficient than an AC motor. It can also continuously vary its speed to provide the right airflow for the heating needs of the moment. And a DC blower motor tends to require considerably less maintenance, and be much quieter than an AC blower.

Air filter: I recommend spending a little extra on a high quality air filter, such as the April Aire, since it provides much better dust removal and doesn’t require monthly changing. (We change ours once a year as part of our annual maintenance.) The more dust you can capture in the filter, the cleaner the air you breathe and the more efficient your furnace will be.

Humidifier: Finally don’t forget that when you turn on the heating, home humidity levels tend to drop, and the colder it gets, the dryer the indoor air becomes. This can lead to more frequent colds, and dryer air doesn’t do as good a job of transferring warmth from itself to your body. So make sure to include a humidifier as part of the furnace installation.

Our own experience – furnace, then heat pump

To give you a concrete example of searching for the best new furnace, let me describe our own situation.

We bought our 1920’s home in 1997 and in our first heating season realized that the old oil furnace was very costly to operate. It had three things going against it: (1) The house stank of heating fuel; (2) We had to pay $300 several times over that first winter to refill the tank (the fuel oil rep told us the furnace was about 60% efficient); and (3) Our home insurance company told us they would not cover us after our renewal date if we didn’t get rid of the oil tank. So we were eager to replace the furnace with the best new furnace on the market – a gas furnace, since there was already a gas line to the house for the hot water heater.

After looking around for the best new furnace brand I narrowed the selection down to three or four models of high efficiency furnace in the 92-95% efficiency range. I contacted each manufacturer to find out which dealers in my area sold their high efficiency models. After a few calls to local installers, I settled on a company that is a good 25 miles away from my home but that really impressed me with their professionalism and thoroughness. They had won ‘Readers Choice’ awards consistently for almost a decade from their local community paper, they had a staff of over ten technicians as well as sales people and admin staff, and the owner himself came out and did a thorough assessment of our home heating needs. He recommended a high efficiency Carrier furnace that had an efficiency rating of 94%. That furnace cost us about $4000 at the time – a good $1200 more than an 80% efficient furnace would have cost – and at the time when I calculated the payback period, it was somewhere in the 15-20 year range. But I don’t regret the decision at all. Gas prices wound up rising faster than I predicted, and the extra efficiency easily paid for itself in reduced gas consumption over the 22 year life of the furnace. The best new furnace or heat pump is pretty much always the most efficient one, as long as the installer has a good reputation, as mine did.

Then in 2020, as part of my goal to completely decarbonize my home, I decided to switch to a heat pump. I called up my old installer (who had also installed a new air conditioner for me a few years back) and asked about heat pumps. He was very dismissive, saying they don’t heat well, don’t handle cold well, and have quality problems. This to me was a classic sign that he just preferred to sell furnaces because he knew the technology. I ditched him, went looking at manufacturers, and settled on another Carrier product, the Carrier Infinity Heat Pump, and used the manufacturer’s website to find dealers who carried Carrier products. I called several who only installed furnaces, not heat pumps. Eventually I found three HVAC companies who would install a Carrier Infinity heat pump. The first company did a thorough job assessing the home energy load and telling me about what I could expect in terms of installation timelines, process, and how the heat pump would work. The second company was a little less thorough but more importantly, their price was $2000 higher, and when I mentioned this to them they instantly dropped their price to match the first. The third installer never returned my calls. I decided to go with the first.

Before I could have the furnace installed, I had to upgrade my panel from 100 to 200 amps, since I was also planning to install a heat pump water heater, a hot tub, and a Tesla charger, and all of those needed high-amp circuits. Then the pandemic hit, which delayed installation by 4-5 months. Finally, the HVAC company installed the heat pump in a single day. By then it was summer, so rather than heat the house, it cooled it quite comfortably, and surprisingly, my electricity bill is no higher now than my combined electricity and natural gas bills were before I switched.

Warranty and service: If you go with a furnace, I strongly recommend buying a maintenance contract and renewing it every year. If you add up those $60-120 a year payments it does work out to a fair bit of money over the lifetime of the furnace. But part of that cost is for a tuneup, which makes your furnace run more efficiently, and the maintenance contract means that no matter what goes wrong, repairs to the furnace are the financial responsibility of the installer, so you get a continually operating furnace at a predictable cost. You can reliably plan to keep a furnace for around 20 years, after which it is probably more sensible to replace it with a new furnace than to keep paying the ever rising maintenance contract fees.

For heat pumps, maintenance may not need to be performed as regularly – for one thing, there’s no combustion of gases, a process that can be highly corrosive, so the equipment tends not to age as quickly. The main things required for heat pump tune-ups are cleaning the coils, checking the presure on the refrigerant, and checking / lubricating bearings on the motors of the fans and compressor. These things can be done every 2-3 years; it’s probably not essential to do them each year.