What Most Customers Believe
Typically, customers believe comfort/air issues are an equipment problem. The customer calls a HVAC contractor and tells them, ‘I’m thinking about replacing my HVAC system, when can you come over?’ A comfort advisor shows up promptly and the homeowner says,’ I was talking to my neighbor and they had a bigger unit installed. I think I need a bigger unit!?
The truth is, until the system is examined and tested, no one has any idea what the problem might be. At County Wide, our Sales/Service Tech’s are trained to verify equipment is sized correctly for the home and conduct static pressure tests to show customers that oftentimes the equipment isn’t the culprit. In fact, it is often the duct system attached to the equipment that is causing the problem.
Poor Airflow Is Common
Unfortunately, customers have been trained over the years to accept poor airflow. Rooms over garages and bonus rooms are usually the worst, but the upstairs in a two-story house is typically 5 to 10 degrees higher than the first floor. Some HVAC contractors usually lack knowledge about airflow, don’t have a room-by-room Manual J and/or D (technical terms), or they use too many rules-of-thumb in duct diagnostic/design. This leads to what happens next.
What Causes the Airflow Issue?
A common airflow problem comes from high static pressure in the ductwork which causes ‘turbulence.’ Turbulence is the physics of airflow that shows how air rolls and tumbles through the duct, almost like a ‘corkscrew.’
The combination of air rubbing against the wall of the duct (resistance) and turbulence in the air stream itself creates friction loss. This friction loss shows up in poorly designed duct fittings because transitions are too short or because of square-throated elbows.
Other airflow issues include dirty ducts or torn/unsealed areas of the ducts. When it comes to dirty ducts, we recommend having your ducts cleaned every 3 to 5 years, especially if you have pets or have recently gone through a major renovation or remodel.
At County Wide, we offer a free Comfort Evaluation that includes checking to ensure that your ducts and airflow is working properly in every room of your home.
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