Solving Mold Spots on AC Vents

A new customer was concerned about mold spots forming on their ceiling AC vents, and they called us to find a solution.

This is an older home in Brandon MS, about 40 years old and was “flipped” before they bought it about 5 years ago. Air Max inspected the HVAC system to find several major problems in addition to the black spots on the white ceiling grills. The problems were major air gaps in the duct work and a lack of return air to the furnace. These issues created a “perfect storm” for the mold growth on the ceiling grills and poor heating and cooling performance.

Our first recommendation and our workaround recommendation:

We recommended replacing the entire duct work system to include an additional return air filter grill in the hallway but the quote was too high for their budget, so they asked for another solution. So we quoted an additional return air filter grill and literally a “stop gap” means to seal their leaky duct work. The price was within their budget so they said, “go ahead and make it happen.”

We installed a new return air filter grill with a 16″ duct back to the return plenum which almost doubled the return air volume and decreased the static pressure, the resistance to airflow, in half also.

So what does that mean?  The heater and air conditioner can now move enough air to heat and cool their home without damaging the equipment and causing the duct work to sweat.

We sealed the gaps and voids in the duct work connections with Hilti expanding foam, which took care of the following:

  • prevents air loss to the attic
  • stops major duct sweating
  • reduces dust and dirt infiltration into their home
  • makes each room more comfortable in heating or cooling.

The ceiling grills were removed, the problematic gaps between the duct boot and sheet rock ceiling were caulked with white latex caulk, grills cleaned and re-installed.

Why was mold forming on their AC vents in the first place?

They were forming because the hot air infiltration from the attic was meeting the cold air from the duct and dirty condensation. All it takes for growth is a food source (dust) and moisture (condensation). We stopped this from re-occurring.

Now our customer has a much safer and more comfortable home due to a plan that fit their budget, and Air Max’s hard work to correct problems that no one saw (including the home inspector).

The old saying, “What you don’t see can hurt you,” but a new saying could be “What Air Max sees can help you,” if a plan, a budget and effort come together.

So if you have mold on your AC vents, a couple rooms that are too hot or too cold, or a loud return air filter grill, you may have the “perfect storm” and need to call Air Max at 601-939-0015 or contact us and have us “see what helps you”!

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