H.V.A.C. System Maintenance
United Trades Exclusive
By Dale Yelnich
Much like residential HVAC maintenance, commercial systems need maintenance too. They should be monitored, checked and inspected on a regular basis, for overall effectiveness and efficiency. Most of the maintenance that is done can be accomplished by regular maintenance personnel on-site, but a once per year certified maintenance inspection is highly recommended. A professional maintenance inspection will always give you a heads-up about any oncoming issues, while making sure your HVAC system is up to snuff for both heating and cooling. But throughout the regular calendar year, here are some of the things that a regular maintenance crew can do to keep a commercial HVAC system running efficiently and effectively all season long.
Change the filters. This is the #1 problem with most HVAC systems in a commercial setting. When filters become loaded and plugged, the system works harder and becomes both less effective and less efficient. A harder working HVAC fan consumes more electricity as it tries to pass air through a plugged filtering medium. This leads to a strain on the motor bearings and drive belts, if applicable, and it will reduce the air quality that the unit serves, eventually causing a breakdown of the fan motor or related parts. Filters are relatively inexpensive, and virtually anyone can change them. Check them at least once per month, bi-monthly in industrial settings, and if they can no longer be seen through when held up to a light, it’s time for them to be changed.
The fan is the heart of any HVAC system, whether it is for heating or for cooling. Fan blades need to be cleaned twice per year, and pay close attention to the leading edge of the blades for nicks, dings or other wear and tear. Inspect any drive belts for cracking or pitting, and any excessive wear on a belt means it should be replaced. Although many fan motors have sealed bearings, some types have oil ports for lubrication, and these need to be filled yearly with a high quality bearing oil. If a fan is squealing or grinding as it runs, either the bearings or the motor must be replaced before full failure occurs.
In HVAC cooling systems, the condenser coils need to remain dirt and dust free. Any type of refuse that contacts or covers the condenser coils will compromise their heat transfer properties. Leaves, trash, and other types of debris will limit the effectiveness of the condenser coils, and that makes a cooling system far less efficient. Keeping the area clean, in and around the coils, ensures that the HVAC cooling system is working effectively, even on the hottest days.
Inspect the ducting system yearly. Look for ductwork that has come apart, split or broken. Split or broken pieces must be replaced, but ductwork that has come apart or separated can be reattached. Always screw ductwork back together where the joints overlap, and using self tapping sheet metal screws will do the trick. Tape the joints with aluminum adhesive tape, or better still, seal the joints with duct mastic for a more permanent solution. Never use regular cloth duct tape to seal joints, even if it touts itself as being of industrial quality. Test after test has shown that cloth duct tape fails, sometimes in less than a years time, and leaking joints on ductwork, due to duct tape failure, contribute to higher energy costs every time.
While the ductwork is being inspected, check the dampers that regulate airflow inside of the ductwork. In most cases, the dampers should be wide open, but if there are rooms or offices that are rarely used, the dampers may only be opened slightly or closed completely. Some commercial dampers are electronically regulated to open or close as needed. These dampers need to be inspected for proper operation, and lubricated to keep them working flawlessly.
Clean the vents and cold air returns on a regular basis. In many scenarios, if a cleaning service is used, this can become part of their regular cleaning chores. A simple swipe of a brush, or a quick pass of a vacuum cleaning wand, may be all that is needed to keep the vents from restricting airflow through them.
Also, schedule regular cleaning of the interior ductwork every two years, every year in a health care setting. Dirt and grime in ducts contribute to less effective airflow, and dust build up may also contain trapped allergens that are released every time the HVAC fan goes on. Cleaning the interior ductwork goes a long way to keeping the air quality clean and healthy in any commercial environment.
One of the best ways to determine what type of maintenance might be needed is to listen to the employees. If there are complaints about an area being too hot, too cold, having musty air quality or if strange sounds are mentioned when the HVAC unit comes on, check it out. People that work in these buildings every day are the most in tune with their immediate environment. If there is a complaint about HVAC performance by someone who works there, the chances are that something is amiss and needs to be tended to.
Although it is true that the best inspections will come from a certified professional that deals with HVAC units in a commercial setting, the reality is that most HVAC system maintenance can be done on-site, for energy efficiency all year long,