Your HVAC system keeps your building cool in the summer and warm in the winter, and it's also an important filtering mechanism. As air rotates through the system, it is filtered and blended with fresh air to keep the air quality for your employees as high as possible. When your system isn't functioning correctly, however, it can have a decidedly negative effect on your building's air quality. Not only is this unpleasant for occupants, but it may also be indicative of a more severe problem. If the air quality in your building seems to be worse than usual, one of these issues may be at the heart of the problem.
Dehumidifying the air is a happy side effect of how air conditioning systems function. As cold refrigerant moves through the evaporator coils, it accepts heat from the surrounding air. Since the coils are cold, water condenses from the warm air. The AC blowers then distribute this cool, dry air throughout your building. If the air from your vents seems overly humid, then it means that the evaporator coils are not cold enough to form condensation.
The most common cause for this situation is a compressor that is short cycling. A short-cycling compressor will shut off too soon, stopping the flow of cold refrigerant through the coils. If the blower is still running, it will move air that is now significantly more humid. Short cycling can have a variety of underlying causes, ranging from bad thermostats to a system that is too powerful for the structure that it is cooling.
Damp or Moldy Smells
Foul HVAC odors are a common complaint from commercial structure odors. If your building's AC vents are producing a moldy smell, then this is likely to be a consequence of humid air making its way through your ductwork. Even if the air is not damp enough to be noticeable, the slightly elevated levels of moisture may be enough for mold colonies to take hold in your vents. By the time you notice the smell of mold, the problem has likely been ongoing for some time.
When confronted with any smell that is out of the ordinary, first check your system's filter or filters. These are rarely the cause of mold smells, but a badly clogged filter may be causing your system to overheat and cycle too quickly. The probably may also lie with clogged condenser drainage lines, especially if the outdoor humidity is high.
Dusty or Dirty Smells
Finally, dusty odors are often caused by dirty filters. Large commercial structures should have their system's filters checked at least every 8-12 weeks and replaced when they are soiled. If you follow this schedule and find that your filters are clogged when replaced, then consider moving your timeline up by 1-2 weeks. While it does not make sense to replace clean filters, filters should not be left in place until they are entirely clogged. Filters in this condition can not only produce bad odors, but they can also potentially damage the rest of your system by causing your evaporator to freeze up.
It can be easy to ignore seemingly minor air quality problems, but remember that poor air quality harms both your employees and your customers. Dealing with air quality problems promptly is better for all of the occupants of your building, and it can potentially be better for your bottom line as well. Contact a commercial air conditioning repair contractor for help with these problems.