When replacing the outdoor unit of an air conditioner or heat pump, should I also replace the indoor unit?

The answer is most likely yes, but this is due to four main reasons:

  • Matched System Design
  • Design Advances
  • Higher Cooling and Heating Efficiency
  • Equipment Age

Matched system design

All outdoor cooling units are designed to work with matched indoor units for greater efficiency and performance. Air conditioners and heat pumps may “work” with other indoor units, but it compromises system performance.

Design advances

In recent years, indoor blower coil units have undergone many design advances. Those advances have affected air handling performance, filtering efficiency, and operating sound levels. A new outdoor unit will also include the latest design advances.

Higher cooling and heating efficiency

The cooling and/or heating efficiency rating assigned to a given air conditioner or heat pump is based on matched system performance. You may gain higher efficiency by replacing only the outdoor unit. But, the efficiency levels (and savings) will not be as high as with a matched system.

Equipment age

Many air conditioners or heat pump outdoor units are 10+ years old and need replacement. If that is the case, the indoor unit is just as old and subjected to the same amount of wear and tear. Replacing both units means you won’t have to replace the indoor unit in a short time. You will have years of service from both units.

New warranty

A new unit also gives you a new product warranty. Replacing the indoor unit at the same time as the outdoor unit gives you added peace of mind. The new warranty will cover the entire system.

Cost savings

At first, replacing only an air conditioner or heat pump outdoor unit may appear to be a bargain. But this doesn’t account for lower efficiency, decreased reliability, and high cost of ownership associated with single-unit replacement. It may cost more to replace an entire system, but this gives you more efficiency, reliability, and comfort.