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Monday, September 7, 2015



I was reading an article titled "Ducts in the Attic? What Were They Thinking?", and it caused me to think about the merits and shortcomings of this practice.

The article was presented at a conference about common building practices and air conditioners and much of it is technical and way too detailed for anyone outside of an engineer, builder, or air conditioner contactor.  That being said, there are definitely strong arguments to made for not having ducts in the attic. 

The article explored the impact duct location has on cooling load,  peak demand, and energy cost in hot climates. They studied climates in Houston, Phoenix, and Las Vegas.
Tampa, FL is probably similar to Houston in humidity and temperature. For an average new home in these climates, they concluded that locating ducts in the attics increased the cooling load significantly, which increases cooling costs and ultimately demand.  Which means bigger carbon footprint.

My house is already built and my ducts are in the attic! What do you expect me to do?  Rip my house apart? Have ugly ducts hanging from my ceiling where I can see them? I won't live long enough (even if I live to be 100) to recoup the costs of refitting my central air conditioner ducts running through my hot as death valley attic!

The perfect time to change this practice is when the house is being planned and built. But for most of us, that ship has sailed.  Let's explore options for the home that is already built and lived in.

All ducts are leaky  We do not want heat exchange in the attic, that is we don't want the cold conditioned air in the ducts to be leaking into the hot, unconditioned attic. One way to reduce the heat in the attic is to use isynene spray foam. It is sprayed onto the underside of the roof.  It is like a layer of insulation on the ceiling of the attic.

If you are really concerned with not losing any conditioned air in the attic and you do not want to have exposed ducts in your air conditioned living space and lowering your ceilings and generally retrofitting your home is out of the question you may  want to consider ductless systems, also known as mini-splits.

Mini-splits have no big, dirty, leaky ducts to deal with. Because of the absence of ducts they are extremely efficient and cost effective to operate.

 A mini-split system could be the perfect solution for those of us in homes with difficult to change ducts in the  attic.

Integrity Air Conditioning would love to discuss your needs and concerns regarding cooling choices.
Call Jay at (813) 932-2665