Blog

Attic Duct Work Upgrade

Heating and Air Conditioning ductwork located in unconditioned spaces like an ATTIC or CRAWLSPACE can pose many problems for a homeowner. 

Today current building and energy codes required all new ductwork systems to be tested for airtightness and have minimum insulation at R-8 in these spaces.

We recently had a customer who moved into a new house. During the standard inspections- all the duct systems were not even mentioned.

The customer found once it warmed up outside the AC system could not keep up and cool the house until long after dark. She also had a complaint about 2 additional items- #1 excessive dust in the house and #2 High electric bills.

Upon a comprehensive home evaluation, we found that although the duct system looked normal it had major issues.

Note: The Air Conditioning unit was new and sized properly for the home.

The ductwork (distribution system) was fabricated out of Duct Board. This is a very common material made out of fiberglass coated with a reflective skin on the outside. It comes in various thickness and inside coatings.   

This particular system had unfaced fiberglass inside surfaces. The inside surface was deteriorated and coming apart. This caused fiberglass particulate to blow through the ducts into the house. Not a good thing, as Fiberglass is a respiratory irritant. The home also had years worth of dust and other contaminants blowing into the living space. 

The second issue was major air leakage.  Every point that supply branch ducts were attached to the duct board main trunks- Conditioned air was leaking into the attic. This is air the customer paid to heat in the winter or cool in the summer. The other major, (what we call catastrophic failure) was the return air side of the system was pulling a large percentage of the return air not from the house but the attic space. The return leak was upstream of any air filters pulling very dirty attic air in and blowing it through the house.  Also, a return duct leak in this hostile environment can cripple the efficiency and capacity of a system. In this case, there was at least a 25% leakage, which means the heating and cooling system may only be delivering 50% of what it should to the house.

The corrective action was to replace all the duct board with rigid metal plenums and trunks. The existing flexible branch ducts were still serviceable and remained. 

The new duct system was assembled outside on the ground. All seams, collars, end caps, and plenums were properly mastic sealed. After the ducts were installed in the attic they were insulated with approx 3" R-19.5 closed cell spray foam. The result is an airtight, super-insulated duct system!

The efficiency and capacity of this customer's new AC system was fully restored. The day we finished it was 97 degrees at noon. Within several hours of cooling the house came down to the set point and has easily kept up ever since. The dust was gone and the electric bills dropped significantly.

Dave Hoh's Home Comfort & Energy Experts completed this work and qualified it as a NJ Clean Energy Program project, eligible for great cashback incentives and long term 0% funding.  This means the project will pay for itself in energy savings!!!! Not to mention the improved comfort and indoor air quality.   

Contact us and ask how we may help your home if you're experiencing similar issues.