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What is an Air Conditioner?

By Anne Fonda 

An air conditioner (A/C) is a device that helps regulate the temperature, humidity, and quality of air in your home. It cools down hot indoor air by removing heat and transferring it outside while lowering the humidity to make the air feel cooler and more comfortable. 

While window air conditioners and portable air conditioners are available, we’ll focus on central air conditioners. Central air systems are the predominant means of space cooling in the United States. A split system central air conditioning system has two components: an outdoor condenser/compressor unit and an indoor evaporator coil.  

How does an air conditioner work? 

The indoor and outdoor units use the refrigeration cycle to work together to cool and dehumidify the air in your home to keep you comfortable.  The refrigerant cools the indoor coil (the evaporator coil), which in turn cools and dehumidifies the air inside your home. The refrigerant then returns back to the outdoor unit where it is cooled back down into liquid form again, and then the compressor pumps the liquid refrigerant back to the indoor unit to repeat the cycle.   

What maintenance do I need to do on my air conditioner? 

Regular air conditioner maintenance can help keep it running efficiently. Make sure to change or clean the air filter every 1-3 months, and keep bushes and tall grass or grass clippings away from the outdoor unit. It is also important to schedule annual AC maintenance visits with a qualified technician who can check the system more thoroughly and make any necessary adjustments. 

How do I choose the right central air conditioning system for my home? 

If your central A/C unit is old (15+ years) and repair costs are increasing, you need to start planning for air conditioner replacement. Get multiple quotes from reputable HVAC companies, and ask them to perform a load calculation to ensure proper sizing. An oversized or undersized AC unit will cause problems such as decreased comfort and higher than necessary energy bills. 

Why does the SEER2 rating matter? 

An air conditioner’s Seasonal Energy Efficiency Ratio (SEER2) measures how efficient it is while cooling over an entire season, in temperatures ranging from 65°F to 104°F. The higher the SEER2 rating, the more energy efficient the unit is at cooling your home. The SEER2 rating is especially important if you live in an area with long, hot summers. 

Why does the number of stages or speeds matter? 

Trane central air conditioners range from single-stage to variable speed.  

Mark Woodruff, Senior Product Manager, Air Conditioners 

Single-stage systems are either ‘On’ or ‘Off’.  That means they either run 100% full power or they are off.  This can make the cost of operation higher than that of other models. If you live in a northern state and don’t run your AC that much, a single-stage unit might work for you. 

Two-stage systems are more efficient than their single-stage counterparts, and will have a high speed and a low speed (usually 100% and 70% respectively), or be off.  

Multi-speed systems are a rather new design and straddle the gap between traditional two-stage systems and variable speed.  They offer better efficiency and humidity control than single or two-stage systems, but are simpler than variable speed systems and are available at a lower price. 

Variable speed air conditioners are the most efficient (and the most expensive to buy) as they can vary their output, running longer at lower speeds to draw the least amount of power required to maintain your desired temperature in the home. They also provide superior humidity control, which can be very important for homeowners in Florida and other parts of the South. 

The bottom line: More efficient systems with more speeds and a higher SEER2 rating will cost more upfront, but can provide better comfort and save you money on your energy costs for years to come. 

Work with your local Trane HVAC expert to enhance home comfort 

If you need AC repair or it’s time for AC replacement, your local Trane HVAC pro can help.  


Anne Fonda, Content Writer

LinkedIn

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.

When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Mark Woodruff, Senior Product Manager, Air Conditioners

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