September 11, 2018
Last week, we discussed the reasons for and against replacing your air conditioner and furnace at the same time. While it can make sense to wait to replace your furnace (if it is less than 10 years old), it NEVER makes sense to install an indoor or outdoor AC unit without also replacing its indoor/outdoor counterpart.
Most air conditioners are known as “split systems” since they are composed of an indoor unit (with an evaporator coil) and an outdoor unit (with a condenser and compressor). Installing a new indoor unit without replacing the outdoor unit (and vice versa) will result in premature failure and much lower efficiency.
Your air conditioner’s indoor and outdoor units must be designed to work together. Mismatched air conditioning systems are more than 30% less efficient and can cause undue stress on the entire HVAC system.
According to the Air Conditioning, Heating and Refrigeration Institute (AHRI), “When improperly matched, the efficiency and longevity of these systems are significantly compromised.” When your indoor and outdoor units don’t match, it can create undue stress on the system, dramatically reducing its expected lifespan.
Imagine putting a donkey and a horse on the same yoke to pull a wagon. The horse wants to speed ahead while the donkey slowly lags behind, causing the cart to slow down. That’s what it’s like to have a new energy efficient outdoor unit but still have an old inefficient inside unit.
Even if your new outdoor unit is 18 SEER, the old indoor unit (probably an 8-10 SEER unit) causes the system to lag behind, keeping your energy bills just as high as they were before.
Mismatched units create undue stress on your air conditioner, resulting in an unnecessary, premature breakdown and repairs. This is especially true if your new unit uses a non-ozone depleting hydrofluorocarbon (HFC) refrigerant (typically R-410A). Learn more about the R-22 phaseout.
Many manufacturers know the problems associated with mismatched systems, which is why they say they aren’t responsible for performance problems associated with mismatched systems.
You also need to think about how much you’ll pay on installation, which strongly affects how much you pay for a new system.
If you are thinking about replacing one coil and not the other, think again. We highly recommend replacing the indoor and outdoor units at the same time!
In a nutshell, in order to be properly matched, your air conditioner also needs a blower motor, which is usually a part of the furnace. In order to ensure your air conditioner performs at its rated efficiency, you should replace the furnace at the same time. But… if your furnace is less than 10 years old, you may want to wait until your next air conditioner replacement to replace the furnace as well. Learn more about whether you should replace your air conditioner and furnace at the same time.
If you’re thinking about replacing your HVAC system, don’t hesitate to contact Service Champions for a free estimate.