It is critical to the overall functioning of heating and air conditioning equipment. When preventive maintenance is not done correctly or is not performed consistently, your HVAC system will require costly repairs at a later date, instead of keeping the system in top shape for a longer time. With maintenance, you can have a little work done now, but if you do not get maintenance, it will be a lot of more costly work done on your HVAC system later. Regular inspections are recommended every year. The operation of your HVAC equipment is verified during an inspection. Mechanical equipment is designed to work efficiently within certain limits. The best insurance against a complete HVAC shut down is preventive maintenance.

AC systems are designed to operate within a range of outdoor temperature limits. Condensing and cooling of the refrigerant vapor is specifically designed to include a particular volume of air flowing within the condenser at the maximum ambient temperature (outdoor – usually 115°F). If the surfaces of the outdoor coils become filled with dirt, the ability of these coils to transfer heat is lessened and the airflow is reduced through the condenser coil because it is blocked by dust and dirt. Air pressure within the AC unit and operating temperatures will increase when the ability to transfer heat is reduced. An AC unit, designed to operate efficiently at ambient temperatures of 115°F or more could stop operating when the outdoor temperature reaches 90°F. Due to the reduced heat transfer capability, the operating temperatures and pressures within the unit will exceed the manufacturer’s safe limit and cause the unit to shut down. If the unit does not shut down, it will continue to run at a reduced capacity and efficiency with an increased rate of wear and energy consumption due to the higher workload. This is why preventive maintenance is so important since it reduces the possibility of wear, repair costs and catastrophic failure.

AC system equipment operates with a specific quantity of air passing over the indoor coil surface. If air filters are not replaced as recommended, they clog and become coated with dust and dirt. Similarly, the indoor coils will also become coated with dirt. This dirt reduces the amount of air flowing in the unit below the design limit, and the HVAC system struggles to keep up and will wear out sooner. In the cooling mode, there needs to be a specific amount of air flowing over the indoor coil, or the coil temperature will drop. If it drops below the freezing point, ice forms on the coil, further reducing the airflow and lowering the coil temperature. A compressor within the unit is a pump, which is designed to pump a vapor. Once the airflow through the indoor coil drops, there is not enough heat being removed from the air passing over the coil, to effectively vaporize the liquid refrigerant inside of the coil. Therefore, instead of receiving a vapor, the compressor will receive liquid refrigerant. This process is called “liquid slugging” and is similar to the effect of pouring a liquid into the cylinders of a gas engine. Since liquids are not compressible, cylinder pressure will exceed the design limits of the cylinder, destroying the valves, connecting rods, internal components and pistons. First, the air conditioning unit requires that its filters be replaced. Next, it needs a new compressor. Would you prefer to pay for preventive maintenance or a new compressor? It’s your choice. When your system is in heating mode, low airflow causes the heat exchanger to overheat. Heat exchangers are made to operate at a temperature range between 120°F and 200°F. If higher temperatures occur, the heat exchanger oxidizes, reducing the life-span, or it cracks and breaks. Either way, it makes a lot of sense to replace air filters regularly than to pay for a heat exchanger replacement.

Electrical relays are designed to open and close a required number of times with a particular current load before the contact points become damaged and relay requires replacement. If more than the design current passes through this relay due to a motor working too hard or low voltage, the contact points will overheat and become damaged. If the electrical contacts in a contractor (large relay) start to get pitted, and the contractor is not replaced quickly, eventually the air conditioner’s compressor motor or the fan motor controlled by the contractor will burn up and require a costly replacement. So, if we exceed the design limitations of the device, or take it well past its anticipated lifespan, additional damage is caused. It is cheap to replace a relay or contractor during a preventive maintenance service visit, as compared to replacing a motor or compressor.

An HVAC system operating with an insufficient refrigerant charge can destroy its compressor via two scenarios. The unit icing up from a low-pressure condition causes the compressor to fail due to liquid slugging, as described before. The second type of failure is due to the fact that the compressor requires a specific quantity of cool refrigerant vapor to cool its motor windings. If the refrigerant charge is not adequate, the motor within the compressor will overheat and burn up. Our technicians can easily spot this condition during a heating and air maintenance visit and save you money.

Bearings and other rotating parts are uniquely designed to have a long, useful lifespan of hundreds of thousands of hours, as long as they are lubricated at designated intervals and are not overloaded due to vibration from dirty blower wheels or defective drive belts. If bearings are not lubricated regularly, they will become overheated and eventually seize. When this occurs, the bearings will fall apart, and the blower wheel, housing, and shaft will be destroyed. This is an excellent example of a situation where inexpensive preventive maintenance would have prevented catastrophic results.

Drive belts become loose or broken, and that causes the same problems that dirty filters cause. The airflow through the equipment will be reduced below design limits, and loose drive belts will slip on the pulleys. This wears the groove in the pulley so that when the belt is replaced, the new belt is ruined faster by the worn pulleys. With preventative maintenance, a $15.00 belt can be replaced regularly, or spend much more replacing pulleys.