Central AC Quality

A major HVAC manufacturer surveyed its customers in 2002 and asked them about their priorities when purchasing heating and cooling equipment. The customers ranked their preferences in the following order:

1. Reliability
2. Durability
3. Efficiency
4. Warranty
5. Comfort

If you've visited the websites of any central air conditioner manufacturers, you've no doubt seen claims about quality, yet no one does systemmatic quality comparisons of air conditioners.

Why are there no Central Air Conditioner Ratings?

With the exception of Consumers Digest no national consumer organization regularly evaluates central air conditioners. There are at least two reasons for this:

1. Many HVAC professionals believe that the installation and maintenance of your furnace at least as important as its underlying components and construction
2. This article suggests a second reason: that the national consumer product testing organizations simply cannot afford to rigorously purchase, install and test central air conditioners. Whatever the reason, you will be hard-pressed to find detailed research into which central air conditioners are the most reliable and durable

Consumers Digest "Best Buys"

Each year Consumers Digest compares some of the major central air conditioner brands in their Annual Buying Guide and chooses a "Best Buy" based on several criteria. Here are some of the recent winners:

• Goodman CLQ was designated a "Best Buy" in the Economy category of the June 2005 issue.
• TRANE XL19i (premium category) and XB10 (economy category) air conditioners received a "Best Buy" designation in May/June 2003.
• Carrier WeatherMaker received a "Best Buy" designation in the May/June issue
• American Standard Allegiance 16 and Allegiance 14 air conditioners were rated a "Best Buy" in June 1998.

How Air Conditioner Components Affect Quality

Without quality ratings, how can you compare the reliability and durability of air conditioners sold by different manufacturers? Here are some of the components that affect the quality of central air conditioners.

The most expensive part of a central air conditioner is the compressor. The compressor increases the pressure on the Freon (or Puron), and releases heat. (The compressor is located outside in a typical split-system air conditioner.) Several manufacturers use scroll compressors instead of conventional compressors in their high end air conditioners. Scroll compressors involve less friction than a conventional compressor and this increases their reliability and typically makes for a quieter unit.

Another mechanism to protect the compressor is a "short-cycle" protector. Short-cycling occurs when the compressor is cycled on and off quickly (within a period of a few minutes) -- perhaps because of a loss or power, or an over-active thermostat. Because short-cycling can shorten the life of a compressor, a short-cycle protector enforces a five or six minute wait after power interruptions.

The casing itself helps to protect the components stored outdoors. Some manufacturers offer special panels, paints and even weather-resistant screws to provide better protection.

While not directly tied to durability, manufacturers are beginning to offer self-diagnostic tools which can assist HVAC contractors during service calls. Some of these tools can also store error codes for several days, or even contact a service contractor directly!