Maintaining HVAC air handlers to obtain low cost of operations can be quite time consuming and use up available man-hours. Management allocation of labor has always been minimal over the past few decades, but now restraints on hiring have been even more noticeable. The result?
Many departments have cut back on necessary coil cleaning, keeping water collection pans free of bacteria and other microbials, and in some cases choosing to put off changing air filters. While on the surface these things seem okay to cut back on, the actual fact is they cause more problems than they solve. Of course the cutbacks seem to provide the owner with more cash flow. But this is surely not the case.
Cutting back on maintenance items as above costs management more money rather than less.
A recent ASHRAE Journal reported a study that was completed in New York on HVAC units that had been cleaned a year previous. What they found was to some surprising; others in the HVAC field might have considered the ASHRAE findings intuitive or expected.
Several air handlers had their coils cleaned after a one-year period. The study found that the clean coils exhibited an energy savings of up to 20% or more than those coils that had been cleaned only one year before. For several air handlers, this amounts to wasted financial expenditures of tens of thousands per year. Balance that against keeping the coils clean throughout the year and one can see that saving a few man-hours does not really compare to this kind of wasted money.
The main culprit is biofilms. Biofilms are very thin layers, in most instances, of bacteria and other microbes. They tend to be sticky. They grow on any surface, and growth is enhanced by the presence of high moisture and nutrients.
Because they are sticky, when any dirt or organic matter bypasses the filter or comes through the filter, the matter impacts upon the biofilms and may stick to the film. Since the overwhelming amount of surface area is the cooling and heating coils, particles that impact and stick on the biofilms on these surfaces insulates the coils even further. It is known that biofilms alone provide the same insulating affect as 5 times that amount of scale.
This is why coils that are apparently “clean” are financial detriments. Knowing this, is it really smart to cut back on spending an hour or so cleaning coils?
But that is really only the start of the issues. We all know bacteria and fungus create VOC’s or odors. In many cases, these can be quite obnoxious. Most managers might believe that since the air handlers are out of sight of tenants, no one really cares if they are in fairly good health. We know of one air handler right now in the North East whose tenants in the building (lawyers by the way) have been complaining of odors for quite a few months.
Not withstanding all of the above, there lies another problem, and that is equipment sustainability. How does having a clean HVAC unit related to the expected lifespan of the unit? Most air handlers may cost anywhere from $25,000 to well over $100,000 to replace. In the vast majority of cases, the owner does not hear this news until the unit is within a few weeks or months of replacement. This can come about by the management not periodically inspecting the units for corrosion and fouled coils.
In the next blog, handling the above in a realistic way that makes sense will be reviewed. Please feel free to comment, we love to hear from our readers.
Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.
Filed under: Evaporator and Condenser Coils, Technical Corner | Tagged: ASHRAE, Cleaning HVAC Coils, coating hvac coils, controlled release technologies, fouled hvac coils, HVAC Bacteria and Fungus, hvac coatings, hvac coil cleaners, hvac coil coatings, HVAC Corrosion, HVAC energy comsumption, HVAC equipment and maintenance costs, HVAC Preventive Maintenance, HVAC Products, hvac system life expansion, Maintaining HVAC air handlers, maintenance and cleaning of the HVAC system | Leave a Comment »