Understand Air Conditioner Units
Central AC SEER Ratings and Cooling System Maintenance
The energy efficiency of a central air conditioner: SEER rating, Condenser and Evaporator maintenance, and cleaning and calibrating an analog or digital thermostat.
Understand Air Conditioner Units
The home AC system is a critical part of the residential environmental control system. In many areas, it's operated for at least half of the year – in some areas, much more. Most home owners call a professional AC contractor for all air conditioner repairs and upkeep. But even though one must be licensed to buy or recover refrigerant, there are many maintenance tasks the average DIY homeowner can perform. First, it's important to understand air conditioner units.
Types of AC Refrigerants: R-22 and R-410A
Portable and central air conditioner systems rely on refrigerants to cool, or more accurately, remove heat from air. The most common refrigerant is R-22, also known by the brand name Freon. But since it's thought to contribute to global warming by damaging the atmosphere by further opening the ozone hole, it's being phased out.
Freon will be replaced with R-410A. This refrigerant is also referred to as Puron, which is its Carrier/Bryant brand name. The cutoff date for the production of Freon (R-22) is 2010. At this point, it's a good idea not to replace an existing air conditioning unit with a Freon one. The newer refrigerant should help stop global warming.
SEER Rating (Seasonal Energy Efficiency Rating)
The SEER rating is one of the most important considerations to keep in mind when shopping for a new energy efficient model. The average air conditioner in the early 90's was only about 6. Today, the minimum has increased to 12 (the minimum allowed by Federal regulations) but some units being produced go as high as 19.5!
The Anatomy of a Central AC System
The central air conditioner unit is usually part of a forced-air heating system. Both systems share the duct system and blower, which distribute air to the home at the temperature set on the thermostat. The condenser typically sits outside the house. Its job is to cool the liquid refrigerant in the condenser coils.
It then pumps the cooled refrigerant to the evaporator coils which are located in the house. At this point, the furnace blower circulates the home's warmer air over the cold coils. Two things happen as a result of this: first, the evaporator coils act as a heat exchanger by absorbing heat from the warm air (usually thought of as “cooling” the air).
The second thing that happens is that the warmed liquid refrigerant changes into a gaseous state. It's then pumped back out to the condenser coils to begin the process anew.
Homeowner Air Conditioner Repairs
Although it takes an air conditioner contractor to install new units and perform refrigerant recovery, there's many springtime maintenance tasks that the homeowner can perform.
Tip – Turn off the air conditioner electrical supply before performing any maintenance task!
- Clean the outdoor condenser coils. Use a very soft brush and soapy water, then rinse well.
- Straighten the cooling fins on the condenser unit. Use a fin comb for this. Be sure to wear work gloves. Fins will slice the flesh like a surgical scalpel!
- Check the unit for level. This ensures that the refrigerant flows in and out of the house as designed.
- Lubricate the condenser fan motor with non-detergent machine oil. There are plastic oil port plugs in the motor housing.
- Clean the evaporator coil drip pan.
- Clean and calibrate the thermostat. Simple analog or digital thermostat repair only takes a few minutes.
