How Long is a Piece of String?
How often does our ducting system need to be cleaned out? Well, that is something like asking how long a piece of string is. The answer depends on a lot of variable factors.
- Is it an exhaust system, a supply system, a return system or a transfer system?
- What area of the facility does it serve?
- Is it in a car park garage or a hospital operating room?
- Is it an office building, a school or an industrial plant?
- What is the ambient air like?
- Is the facility located near a dusty construction site?
- Is it in the flight path of a busy airport?
- Are there a lot of trees around?
- Where is the fresh air intake located? Does it pick up diesel fumes or other toxic VOCs?
- What type of filtration is being used and what procedures are in place for changing filters properly?
- If it is a newer building, was it properly commissioned? Did we start with clean equipment?
OK. That was a lot of questions but it is not nearly all that we have to ask in order to determine the cleaning cycle of an HVAC system. In answering the original question, it is somewhere between six months and twenty years.
An inspection of the internal hygienic conditions is really the only way to determine if any particular system is due for cleaning. We suggest an annual inspection of the ducting and air handling unit, with special attention to the coils, the fan plenum, turning vanes and diffuser sites.
This can be a quick inspection with a written report. After a few years, enough historic information will be available to set the cycle for cleaning. It may well be that cleaning all HVAC systems within a whole building is the best way to keep hygienic conditions at optimum levels. Or it may be that cleaning the air handling units on a five year cycle and the ducting on a ten year cycle will work best in your circumstances.
Often, the exhaust and/or returns require cleaning more often than the supply side.
Some exhaust systems require cleaning on short intervals. Kitchen Exhausts (grease hoods), in some jurisdictions, are required by law to be cleaned every six months.
Hotels with busy booking schedules may need their washroom exhaust ducts cleaned annually.
Hospitals have more stringent requirements than other types of facilities. Operating theatres may be cleaned annually and clean rooms will likely be cleaned as often.
Here is an image for you. BUILDINGS BREATHE. It is a metaphor of course, but think about it. Air comes in from a number of places and air goes out from a number of places. The HVAC system is like the LUNGS of the building. If it is not designed and/or operating properly, then the building becomes sick.
Don’t let your building become sick. We can give your building a check up to see if it has healthy lungs.