As your AC system approaches the end of its life, maintenance and repair costs will often begin to exceed the cost of installing a new system. It can be tempting to consider an upgrade when replacing your old air conditioner. Everyone wants to be more comfortable—shouldn't a more powerful air conditioner keep your home much cooler? Unfortunately, the answer to that question is not as straightforward as it may seem.
Below are three reasons that "more" is not necessary "better" when it comes to air conditioners.
1. Old Systems Become Less Efficient Over Time
If your current air conditioner does a poor job cooling your home, then you may understandably believe that it's too weak to get the job done. Unfortunately, air conditioning systems more than ten or fifteen years old likely have several old, worn-out components. The wear and tear on these parts can impact the efficiency and operation of the system, which reduces its ability to keep your home cool.
Your original installers likely chose a system sufficient for your home's size and cooling needs. As long as your system did not struggle to cool your home when new, then it's likely that you only need to replace it with an equivalent system. If you are still concerned, your contractor can help you to evaluate your home's specific cooling needs.
2. Oversized Systems Are Inefficient
All air conditioning systems work by cycling the compressor on and off, usually in fifteen- or thirty-minute increments. An oversized system will cool your home faster, forcing the compressor to turn off before it can complete a cycle. Rapid cycling wears down components more quickly and uses more energy, ultimately increasing your utility costs without making your home any more comfortable.
3. Extra Cooling Capacity May Decrease Comfort
Your thermostat setpoint tells your air conditioner when to shut down, but you typically cannot control the actual temperature of the air it produces. An oversized system may cause your vents to produce frigid, uncomfortable air. Even worse, the quick cooling cycles can lead to severe incidences of hot and cold spots throughout your home.
Oversized systems even tend to produce more humid air. Moisture in the air condenses onto the cool evaporator coils while your compressor is running, dehumidifying your home's air in the process. When your system cycles too quickly, it may not remove a sufficient amount of humidity before shutting down. This effect can produce cold, clammy, and ultimately uncomfortable air.
If you're replacing your old air conditioner, remember that equipment upgrades won't always lead to a cooler, more comfortable home. Always work with an experienced HVAC contractor to get an AC replacement that's the perfect size for your specific needs.