Should You Replace Your Furnace and Air Conditioner at the Same Time?

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It’s become almost “common knowledge” that replacing your furnace and your AC at the same time is the way to go. That’s not necessarily true.

There are times when replacing both makes sense, and times when it doesn’t. 

We’ll go over the different situations where you might want to consider replacing both, and when you can take care of just one. We’ll also talk about the advantages of installing an all-in-one heating and cooling geothermal system from Dandelion the next time you do need an upgrade.

First, let’s look at the things you’ll want to take into consideration when thinking of replacing both the furnace and AC at the same time.

How long do furnaces and air conditioners last?

Consider the age of both your furnace and your air conditioner. Most furnaces have an average life expectancy of 15 to 20 years, while air conditioning systems typically only last 10 to 15 years. If a furnace is well maintained, it might last up to 30 years.

Since a furnace can last about twice as long as an AC, replacing both only makes sense if the furnace is at least 15 years old. By this time, you’re likely seeing some dip in efficiency from your furnace anyway, and your air conditioner is in the winter of its life.

How close are you to retirement?

Retirement is a big lifestyle change, which includes adjusting to a fixed income. Because of this, many people who are nearing retirement invest in major home maintenance while they’re still working.

The idea is to fix up the house to make sure everything runs in tip-top shape through the golden years.

Consider the efficiency rating of your air conditioning unit

If your air conditioner has a Seasonal Energy Efficiency Ratio (SEER) of about 16 or higher, then replacing the furnace at the same time makes sense.

The reason is that your super-efficient air conditioner will be a mismatch with your older furnace’s blower motor, compromising that high-efficiency rating.

How do a furnace and air conditioner work together? 

While a furnace and air conditioner are separate systems, they share the blower motor that distributes either hot or cold air through your home.

An updated blower motor for both your furnace and AC will ensure the new air conditioner will actually reach its efficiency rating.

Consider the relative ease of accessing your HVAC equipment

If your furnace and internal AC components are in your basement, a closet, or somewhere fairly easily accessible, replacing each at different times won’t be a big deal.

But if the technician will have to wriggle his or her way through a tiny crawlspace to reach the parts that need replacing, it could impact the labor costs of your new install. 

Or, if you live in a remote location where even the trip out to you would be more costly for the tech, taking care of both the furnace and the air conditioner at the same might be a good idea.

Of course, if you just installed a new furnace three years ago and your AC gives up the ghost, getting a new furnace doesn’t make any sense at the moment.

3-in-1 heat, central AC, and warm water with Dandelion Geothermal

Another option altogether is to kill not just two but three birds with one energy-efficient stone. 

Dandelion Geothermal systems work by installing a loop of pipes underground. These will typically be in your backyard or beneath your home. A heat pump moves heat-conducting fluid through these pipes.

Latent thermal energy from the sun keeps underground temperatures around 55 degrees year-round. In the winter, the fluid in the pipes works with the heat pump to extract this warming energy from the earth and distribute it through your home. This heat can also be applied for warm water.

Then, in the summer, the geothermal heat pump works in reverse. It collects hot air and humidity from within your home and releases it safely into the ground.

Read more details about how geothermal heating and cooling works in this comprehensive article: All You Need to Know About Home Geothermal Heating & Cooling


Some major reasons geothermal is the best buy


System lifetime

Apart from getting way more bang for your buck with three systems at once, the longevity of a geothermal system outperforms traditional heating and cooling by a long shot.

As we mentioned earlier, a furnace may last 15 to 30 years before it peters out, and an AC only 10 to 15. This adds up to two separate major replacements within a 30-year time span.

With geothermal, the major component (the ground loop system) will last for 50 years or more. The heat pump might need to be replaced around year 20, but this is a small and relatively inexpensive repair. It’s just a few hundred dollars, compared to several thousand to replace a furnace and AC.



Maintenance during the lifetime of a geothermal system is also significantly minimal compared to furnace and AC repair. 

While you’ll need to call the technician for yearly maintenance and any other issues that frequently pop up with AC coils and compressors or furnace parts, there’s not much to be done with geothermal, other than occasional air filter replacement.


No fuel or gas

With geothermal, there’s no anxiety about the climbing cost of fuel or gas to heat and cool your home. There’s also no more worrying about indoor pollution from burning fumes or possible carbon monoxide leaks at home.


Save money with incentives

Lastly, even with all the reasons geothermal is a smarter investment than a traditional furnace or AC, there’s more to be saved.


Thanks to some generous tax credits and incentives, the cost of installing geothermal can be significantly reduced! Find out more about how these incentives work and how long they’ll be around here: The 2019 Federal Geothermal Tax Credit: Your Questions Answered.


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