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Should You Replace Your AC and Furnace at the Same Time?

replacing ac and furnace at same time

Many people wonder whether they should replace their air conditioning unit and furnace simultaneously or if it’s better to do one at a time as needed. While replacing both units may be an expensive cost upfront, it can save you money in the long run with better energy efficiency rates.

In general, your furnace will most likely last longer than your air conditioner. The average lifespan of a furnace is 15 to 30 years, while the average lifespan of an air conditioner is 10 to 15 years. Your furnace may last twice as long as your AC unit, so why should you replace them at the same time?

If you’re thinking about performing a furnace or air conditioner replacement in your home, here are some reasons why Cates Heating and Cooling recommends doing so at the same time. We will also cover when you shouldn’t replace both together.

Overview of an HVAC System

For most homes, heating and cooling equipment work together. The combination of your air conditioning unit and your furnace forms your home’s HVAC system. The furnace provides heat to your home by communicating with the air conditioning unit to distribute heated or cooled air throughout your home, depending on the season.

The air conditioning unit can be a split or packaged system. Split systems have two main units: the condenser coil and compressor make up the outside unit, while the air blower and evaporator coil are contained in the inside unit. With packaged AC systems, there’s typically no outdoor unit; instead, all components are in the same place inside your home.

Because these systems work together, too much power on one over the other can be harmful. If your newer AC unit puts too much power on an older furnace, your furnace won’t be able to handle the capacity, and vice versa. To ensure your HVAC system is ready to take on any changing weather, it’s a good idea to replace your furnace and AC unit at the same time. If one unit fails, there’s a good chance the other is not far behind from doing the same.

When You Should Replace Both at the Same Time

The best way to ensure your air conditioner performs at its highest rated efficiency is to replace your furnace at the same time. This is because your AC unit uses the fan in your furnace to blow conditioned air into your home. Without this fan, your AC unit won’t create proper airflow or push air effectively throughout your home, and the heat exchanger and evaporator coil won’t operate at their rated efficiencies.

Air conditioners with a high Seasonal Energy Efficiency Rating (SEER), such as a rating above 16, won’t work at their rated efficiency if your furnace has an old fan motor. That’s why if your furnace is over 15 years old, you should always replace both units at the same time.

Other reasons these two units should be replaced at the same time include:

  • Cost: An HVAC replacement cost can be expensive. However, replacing these two units at the same time can save you money in the long run by lowering your utility bills, reducing the need for repairs, and minimizing the cost of installation. Replacing a furnace by itself can cost anywhere from $2,000 to $5,000, but if replaced with your AC unit, that cost can be reduced to $1,000 to $3,000.
  • Comfort: With your AC unit and furnace performing at their best, the temperature and humidity in your home will be better maintained. This will improve your home’s comfort level and air quality no matter the season.
  • Age of Furnace: Furnaces that are 15 years or older will reduce the efficiency of your home’s HVAC system. This makes your air conditioner replacement cost an impractical expense because it can’t operate at its rated level. When considering the cost of repairs and maintenance you’d need to make later, it’s best to install a new furnace rather than keep your current one. If your furnace is approaching the end of its lifespan, choose a new unit that contributes to the overall efficiency of your HVAC system.
  • Installation: Certain standards are put in place by organizations like ENERGY STAR®, Air Conditioning Contractors of America, and the American National Standards Institute to ensure that HVAC installation is done correctly. Replacing your air conditioner and furnace simultaneously guarantees that you meet these guidelines.
  • Maintenance and Repair: Replacing your air conditioning unit and furnace at the same time will reduce the number of repairs you’ll need later on. Less maintenance will save you money, and you won’t have to stress about HVAC repairs for a lont time. To keep your system on track, sign up for an HVAC maintenance plan.

replacing ac furnace at the same time

When You Shouldn’t Replace Both at the Same Time

The only instance when you don’t need to replace your air conditioner and furnace at the same time is if your furnace is less than ten years old. The average lifespan of a furnace tends to be twice as long as an air conditioning unit, so newer furnaces can still be used for a while as long as they are functioning properly.

Factors to Consider When Replacing Both

While cost is one of the main reasons to replace both your furnace and AC units at the same time, there are also other factors to consider, such as:

  • System Age: If you initially installed both units at the same time and the air conditioner seems to be nearing the ends of its life, it is likely that your furnace is as well. To maximize the return from your investment, replace both units as your HVAC system ages and nears the end of its usable life.
  • SEER Rating: Higher SEER ratings mean more energy-efficient units. A higher-efficiency HVAC system in your home can reduce energy costs significantly for you and your family, as well as offer comfort benefits. When replacing your AC unit and furnace, look for SEER ratings above 16. Ratings of 13 to 14 are the minimum, and a 15 SEER rating is considered good. If your furnace and AC units aren’t replaced simultaneously, you aren’t guaranteed the SEER rating you paid for since the older system tends to hinder the newer one.
  • Maintenance Contracts: Even with the best HVAC systems and replacements, maintenance and repairs may still be necessary in the future. Debris, dirt, and other substances can build up in your HVAC system, causing erosion to electrical connections or other expensive damage. Dirt buildup will also decrease your system’s efficiency rating since it has to work harder to maintain the ideal atmosphere in your home. Maintenance contracts can guarantee that both your AC and furnace units will be cleaned and maintained annually, preventing expensive repairs and extending the life of your HVAC system.

If you’re looking to replace your AC unit and furnace, Cates Heating and Cooling is here for you. We offer HVAC service plans and repairs, whether you choose to have both units replaced at the same time or not. We even have financing options to fit any budget. Contact us at 913-888-4470 for Kansas residents and 816-944-1844 for Missouri residents to schedule your system replacement today!

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