We can all agree that replacing an air conditioner and a furnace at the same time is expensive.

However, to make sure that your air conditioner works properly you should replace your furnace at the same time.

The average lifespan of a central air conditioner is about 15-20 years, where a furnace can last 15-30 years. In general, furnaces last longer than air conditioners — sometimes over twice as long.

In this article, we’ll explain why replacing your air conditioner and furnace at the same time (in order to install a “matched” system”) is probably the best choice. We’ll also discuss why you may NOT want to replace both systems at the same time.

Why you should replace your air conditioner and furnace at the same time

The blower is used to blow conditioned air throughout your home.

This blower is necessary to produce the proper airflow for the evaporator coil and heat exchanger to operate at their rated efficiencies. It is also what pushes the air throughout your house.

Split air conditioners have two main units:
  • The Outdoor Unit contains the condenser coil (1) and compressor (2)
  • The Indoor Unit contains the evaporator coil (3) and air handler/blower (4)

It’s necessary to replace both AC components in a split system together. However, you do not have to replace the AC components and the furnace.

Still, the air conditioner will need to use the blower motor. To make sure the AC will perform properly, you must the heating system at the same time.

For instance, if you choose a high-efficiency air conditioner with a SEER rating above 16 and your furnace has an old blower motor, you are using a mismatched system which will sacrifice some efficiency. We don’t recommend that you mix and match the systems, especially if the furnace is over 15 years old.

Replacing the outdoor unit while leaving the old blower will result in lower efficiency and could result in premature failure and other problems.

Note: You should always replace both air conditioning components (condenser/compressor and evaporator coil) at the same time. This does not necessary mean it always makes sense to replace the AC and the heating system at the same time.

Keep in mind that replacing a furnace on its own will cost around $2,000 to $5,000. Adding a furnace during your air conditioner replacement will cost a lot less, around $1,000 to $3,000.

The only time it really makes sense to wait to replace your furnace is if it is less than 10 years old. This way, the furnace will most likely last until the next time your air conditioner needs to be replaced.

When to replace air conditioner and furnace at the same time:

  • If your furnace is over 15 years old.
  • When you are buying a high-efficiency air conditioner with SEER above 16.
  • In the case the installation is complicated.
  • If you don’t want to worry about HVAC repairs and replacements for a while.

When NOT to replace your furnace and air conditioner at the same time:

There’s really only one instance when you should consider waiting to replace your furnace at the same time as your air conditioner — if the furnace is less than 10 years old.

In most cases, if the furnace is less than 10 years old, you are probably better off waiting until your next air conditioner replacement. A furnace will last about 20-30 years, while air conditioners should be replaced every 10-15 years.

Get a Free Estimate

In the end, the decision is yours. Although, we highly recommend speaking with a contractor before making the final decision. Having a blower that matches your new air conditioner is necessary to maximize your system’s efficiency, reduce your energy bills, and extend the life of your new system.

To see how much it would cost to just replace the air conditioner versus replacing the entire heating and cooling system, contact HVAC Experts for a free estimate.