Several times per day, our technicians add refrigerant to air conditioning systems. Each of these systems is leaking refrigerant. Air Conditioners do not consume refrigerant; they only leak it. A well maintained and repaired air conditioner may run 20 years on the original refrigerant charge.
The biggest source of leaks is the indoor coil. Most every brand is manufactured with copper tubing. American Standard is different. All split-system indoor and outdoor coils
in our indoor and outdoor units are made with aluminum tubing.
When you replace the indoor coil with a direct replacement for what is currently installed, you are limiting your future options on the outdoor unit selection. You can replace just the indoor coil but I only advise that on houses that you don’t plan to own for very long. Even if you do plan to sell soon, older equipment results in a lower appraisal during home inspections; some of the savings of a replacement coil are offset during the sale.
I always advise the installation of a coil that is compatible with a high-efficiency outdoor unit. Our procedure here is to:
- Install an indoor coil (for gas furnaces) or air handler (for heat pump systems) that is compatible with a 15 SEER or higher outdoor unit using R410a refrigerant
- Convert it to R22 refrigerant if that is what you are currently using
- Leave the parts from conversion with the homeowner for future use with a future outdoor unit.
The wisdom of this approach is in the reduction of wasted material and labor. Also, the repair expense is spread over two events; now to correct the leak and later when the outdoor unit does fail.
Another advantage is an immediate increase in efficiency. While the outdoor unit consumes most of the electricity, the indoor coil plays a large role in that consumption as well. The indoor coil meters the flow of refrigerant through the system. Older coils often use a fixed orifice to meter the quantity of refrigerant through the coil. In older less efficient systems this was acceptable. Newer systems operate at a lower compression ratio and are more sensitive to lower ambient conditions. All quality systems now use either TXV’s (thermostatic expansion valves) or EEV’s (electronic expansion valves). These valves modulate in reaction to varying indoor and outdoor conditions. The valves allow the use of more of the indoor coil in cooler weather and remove much more water from the air.
Copper coils weren’t always leak problems. There are several reasons that merged in the past three decades to make them a huge expense for a homeowner. All-aluminum coils solve many problems and save many tens of millions of dollars in expense over their lives nationwide.
So to return to the question posed in the headline of this article, do you have to replace the entire system. You can confidently replace just the indoor unit by itself. You cannot replace the outdoor unit without a matching indoor unit. That is the reason for installing an improved indoor coil or air handler now. That prepares your system for future upgrades without the wasteful discarding of good equipment at that time.