Because of the value of real estate or the preference by homeowners to place equipment out of sight has led to many HVAC systems to be placed at the roofs. This placement poses unique maintenance and installation challenges primarily related to access and weather. For such equipment, the first priority for homeowners is to ensure they are installed correctly and operate as expected. Improper installation can result into early failures which tag along additional maintenance throughout the equipment life.
Beyond installation, homeowners must think about preventive maintenance issues. In coming up with a preventive maintenance plan, the homeowners should be aware of the equipment located on roofs, their service concerns, as well as the roofing system protection. The following discussion looks at some of the common roof-mounted HVAC equipment and their maintenance requirements.
The type of fan will determine the maintenance requirements. Whether it is a large-belted vent set or a standard centrifugal exhauster, fans need to be inspected visually for electrical disconnects. Typically, fans need a belt adjustment and a regular check on pulley alignment 3 weeks following the installation and thereafter every 3 months. Also, the dampers and actuators needs to be checked every 3 to 6 months and lubrication of motor bearings and fan wheels.
Air Handling Units
Irrespective of the type of air handling units, they have certain parts in common such as coils, housings, fans, dampers, and actuators. The coils and their casings must be checked semi-annually while the drains and drain pans located on the cooling units must be checked and cleaned every 3 to 6 months. Drains usually suffer obstructions which may cause pans to overflow and the condensate finding its way into your home. Filters should also be maintained based on the type of filter, filtration levels and relative air cleanliness.
Chillers and Condensers
There are three basic types of compressors used by air-cooled chillers; reciprocating, scroll and lottery screw compressors. Each of these requires different inspection and maintenance approach based on the manufacturers’ direction. In addition to the compressors, other components such as condenser fans also require maintenance.
Following installation, cooling towers should be inspected for unobstructed airflow and adequate freeze protection for the make-up lines, sump and overflow lines. For an efficient and high performance cooling tower, you must keep a close eye on dissolved solids and bacteria. Bearing lubrication, fan motor, and fan belts must be inspected monthly.
During the installation and maintenance of this rooftop equipment, care must be taken to ensure no damage on the roof materials. The best way to do this is to establish a simple guideline that protects the roofing system during installation.