The basic design of heating and air conditioning systems has not changed much in over forty years. The systems main components are a furnace, a cooling coil, and a condenser.

Ducts, grilles, thermostats, refrigerant lines and electrical wiring are also needed for a complete system, but for now, we’ll just go over the main system components.

The Furnace – Most homes in our area have natural gas furnaces. The furnace has a burner section and a blower section. On a call for heat, the burners light and the heat exchanger (firebox) heats up before the blower starts moving air across the heat exchanger, through the duct system and into your home.
Furnaces have a life expectancy of approximately 20 to 25 years. If your furnace is approaching 20 years, and needs a major repair, or if you are replacing any of the other major components, consider replacing your furnace at the same time. New furnaces are more efficient and come with a new warranty from the manufacturer.

The Condenser – The compressor and condenser fan motor are the primary components in the condenser. There are also some other electrical components, but the compressor and condenser fan motor are the main parts.
The refrigerant, commonly known as Freon, is compressed by the compressor and moved into the cooling coil. The blower in the furnace moves warm air from your home across the cooling coil and provides cool air into your home through the ducts. Condensers usually last about 20 to 25 years.
If the compressor fails prematurely, the cause is usually the system design. So, replacing a compressor without solving the problem will result in another failure.
When replacing a condenser, remember that the cooling coil must be replaced at the same time. If the condenser is more than 10 to 15 years old, replacing the compressor or any other major component may not be a good choice. New units are substantially more efficient than older units and will help save money on your electric bill.

The Cooling Coil – This is located adjacent to the furnace. It allows the refrigerant to absorb the heat from the air in your home. The unit also has drain pan, which allows water, in the form of condensation, to be removed.
The coil is usually trouble-free, as it has no moving parts. Coils last about 20 to 25 years and should be replaced when any of the other major components are replaced.

It is important to choose a quality brand, but it is more important to have the equipment installed properly. Heating and air conditioning systems are different than appliances that simply require plugging into a receptacle in order to work.

These systems, if installed by skilled and trained professionals, will last for many years. Any of this work will be expensive, but don’t skimp on this important investment. Spend enough to get a knowledgeable contractor and a quality brand.

We will be discussing equipment replacement in greater detail at our next Homeowners Workshop. There is no cost, no calories and zero carbs. So, come and join the fun! If you are interested in attending call (818) 886-2600 to make a reservation. Join us and your neighbors for a cup of coffee and some useful information.

Jim Berry was a heating and air conditioning service technician prior to becoming a Sales Consultant for Kahn Air Conditioning. Kahn hosts free monthly workshops to help homeowners learn more about heating and cooling systems. For questions regarding heating or air conditioning, send an e-mail to Jim at

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