If the compressor in your outdoor unit goes out, but the indoor unit doesn’t have any problems, you may wonder whether you can save money by only replacing the outdoor portion of your HVAC system. Technically, in some situations it is possible to replace one without replacing the other. However, even when it is possible, it’s generally not a good idea.
First, air conditioning units are designed to function in matched sets. When they don’t match, it decreases efficiency and increases wear and tear because the whole system has to work harder. Your new outdoor unit may have a high efficiency rating, but if your older indoor unit has lower efficiency, you’re not going to reap the benefits. Essentially, an air conditioner can only be as efficient as its least efficient part.
Second, if your indoor unit was installed prior to 2010, it may use R-22 refrigerant (Freon). Since then, the federal government has banned the installation of new units that use R-22. All new units must use R-410A refrigerant (Puron) instead. Older R-22 units cannot handle R-410A, so you can’t connect a new outside unit to an older indoor unit that was designed for R-22.
Third, overall the new technology available for air conditioning today is significantly better than the older systems. New systems have higher efficiency ratings, are better at filtering dirt and debris, produce less noise, and are better at maintaining correct airflow through your home. Replacing only half of your system will undercut these advantages, sort of like putting old, bald tires on your new sports car.
Finally, if you only replace the outdoor unit, you may not get full warranty coverage on it. That’s because manufacturers know that mismatched systems have more problems than matched ones. In order to get the most benefit out of your warranty, you need to replace both units. That way you’ll also have peace of mind, knowing that your entire system is covered.
Ultimately, while replacing only the outdoor unit may seem like an easy way to save money, in the long run replacing both units will ensure the highest level of efficiency and dependability, both saving you money and increasing your peace of mind.