How Do Air Ducts Get Dirty

Compared to years ago when we heated our homes with wood or coal, a modern day heating system is a marvel of efficiency, reliability and convenience, but just like the old time systems these new systems get dirty and need to be cleaned and maintained.

How does an HVAC system Work?

Now you might be thinking “We keep a really clean home, shouldn’t out ducting heating and cooling system be clean to?”   To answer that question we have to start by looking at how you’re heating and cooling system works.  Think of your homes heating and cooling system as the lungs of your home.  The system pulls air from the rooms of your home through the return ductwork, and then the air passes through the filter before reaching the air handler or furnace where it is heated or cooled depending on the season.  Once the air is heated or cooled, it is blown through the supply ductwork and back into your home.  Some of the components of the furnace are used only during heating, others only during cooling, and others operate all the time.  Although the air is filtered, the fact is that filters cannot remove all the contaminants from the air, the system will get dirty through normal use.

HVAC components that get dirty:

  • Return air ducts
  • Filters
  • Blower
  • Heat Exchanger
  • Cooling coils
  • Supply ductwork

Where Does Dust Come From?

So where does dust come from?  Consider that up to forty pounds of dust is created each year from in the average six room home, this normal household dust is unavoidable as it is created by everyday living.  Every time we open the door, walk across carpeting, scratch out dry skin, or unroll paper towels we contribute to airborne dust.  Of course pets and dust emitting activities such as remodeling make the problem worse.  In fact, it’s not uncommon to find construction dust in a homes heating and cooling system years after the house was built.  On average, this contaminated air recirculates throughout your home five to seven times per day.  Why does it matter? This can develop into a serious problem.  The build up of these contaminants on components such as blowers and cooling coils can lead not only to unhealthy air for your family to breathe, but also to higher energy bills.  These contaminants can cause your system to work harder and run longer shortening the life of your equipment.  Perhaps most importantly the heating and air conditioning system needs to be cleaned to provide the thermal comfort you expect.

How Do You Inspect the Heating and Cooling System?

So how clean is the heating and cooling system in your home?  Here is a quick way to check.  Remove a vent cover and use a mirror and flashlight to look inside.  Or use a small digital camera to take a picture of the inside of your duct.  If your ducts are dirty it is time to have your air ducts cleaned.  Periodic air duct cleaning keeps your homes heating and cooling system clean and operating at peak efficiency.