Remember that getting the proper size and a quality installation is essential to getting the most from your new equipment. When replacing HVAC equipment, bigger does not always mean better. Oversized equipment will cost more to install, create more wear and tear due to frequent cycling, and may not properly remove humidity from the air — resulting in an uncomfortable home.
The seasonal energy efficiency rating, or SEER, compares the cooling power of the equipment to its electricity use. Focus on Energy recommends buying a unit that has a SEER of 16 or higher for optimum savings. Adding a thermostatic expansion valve (TXV) is also recommended and helps your air conditioner be less sensitive to irregularities in airflow or amount of refrigerant. These valves are standard in some systems, but can be added to others.
When selecting a new AC unit you should also look at moisture performance. Your comfort depends as much on controlling humidity as it does on keeping cool. Air conditioners vary in their ability to remove moisture from the air. Ask your contractor about the performance of the units you are considering.
Air-conditioning costs depend partly on the furnace blower that distributes the cool air. If it is inefficient, your electricity costs could be quite high. If your furnace is old, consider replacing it with a model that has a variable-speed blower motor. You will get the benefits of quieter operation and lower electricity bills. Focus on Energy recommends setting your fan on “auto,” even if you have a high-efficiency blower motor. Not only will running your fan continuously cost more money, it will also increase the humidity level in your home, making you less comfortable.