With the rising costs of energy in Winnipeg together with the longer and more humid summers that we have experienced, it makes sense to maximize the efficiency of your HVAC system. Both condenser (outdoor) and evaporator (indoor) coils are engineered to provide optimum heat transfer required for the area needing cooling and conditioning. The air being transferred, in most cases, contains a mixture of dust, pollen, dirt, grease and moisture. These contaminants settle on the surface of the coil and impact the ability to transfer heat. They also a
Restricted heat transfer causes the compressor to work harder, increasing the head pressure. Rising head pressure will result in a loss of cooling capacity of up to 35 percent. (Example: If our 2-ton system with a 35 percent loss is now only providing 1.3 tons of cooling, the system will cost more to operate and provide less cooling. You will usually only notice this loss on the hottest days, when cooling is needed the most!)
Higher operating pressures caused by a dirty condenser (outdoor) coil will also reduce your equipment’s life expectancy. The restriction of heat transfer and strain placed on the compressor can lead to equipment failure. Compressor failure means no cooling. Compressor replacement cost is a whole lot more than a cleaning!
NOTE: Do not judge the cleanliness of a coil by its visual appearance.
Air conditioning cooling coils (indoor evaporators) provide moisture, cool temperature and various forms of dust; all which contribute to contamination growth which affects the cooling coil in the following ways:
- Reduced heat transfer.
The contaminants on the coil surface act as an insulation media between the air and the cooling coil. The air flowing through the coil is not reduced in temperature enough to adequately allow the system to cool the building efficiently. The compressor will then run continuously to compensate for the poor temperature transfer. In a system where the air is cooling the building efficiently, the compressor should cycle in and out of service as required. Only on the hottest days should an Air conditioner run steady during the afternoon and into the early evening. Poor heat transfer results in poor energy savings.
- Blockage in the coil.
This decreases the amount of air passing through the system. This in turn affects the air conditioner’s ability to cool the air. The coolant will actually freeze up the coil instead of transferring to the airstream. The compressor will keep running and create a Popsicle like build-up on the coil completely blocking the airstream through the ductwork and registers. Effective maintenance on the cooling coil provides cost savings in energy consumption.
- Poor Indoor Air
A dirty evaporator coil creates an excellent breeding ground for bacteria and mold that can impact a home or building’s indoor air quality. Cleaning, sanitizing and protecting the evaporator coil, condensate pan and surrounding areas is critical.
- Corrosion of the coil.
Contaminants attach themselves to the fins of the cooling coil. Over time, they become etched into the surface to provide a secure bond. This eats away at the cooling coil and over time degenerates the cooling coil’s ability to perform efficient heat transfer. The solution for coil corrosion is to remove contaminants through regular maintenance. The alternative is to replace the cooling coil, which comes at a greater cost than coil maintenance.