Spray Foam in Hot Climates | Unvented Attic


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Using spray foam insulation in hot climates

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Illustration  Icynene spray foam insulation in unvented attics

Hot or warm climates like the southern states of the USA can benefit equally as well as their northern counterparts from spray foam insulation. In fact, one area of the typical family home that can benefit from spray foam insulation is the unvented attic.

A report titled Energy Efficient Homes: The Duct System from The University of Florida - IFAS Extension suggests that typical duct systems lose up to 40% of heating or cooling energy leading HVAC equipment to work harder.  According to the report, ducts leaking just 20% of the conditioned air passing through them cause your system to work 50% harder. In turn, duct leakage not only translates to higher utility bills but also can contribute to mold problems as well as potential health and safety issues.  To combat these potential issues, installation of spray foam insulation like Icynene Classic Max in an unvented attic in hot climates like Florida and Texas can allow:

  • duct leakage to remain in the conditioned space, eliminating the loss of conditioned air
  • increases the efficiency of the HAVC equipment
  • maintains a temperature in the attic space roughly 5o to 10oF within the living environment below
  • Plus, spray foam insulation products like Icynene Classic Max allows builders to build homes with an attic configuration available on the market

The graphic below demonstrates how an unvented attic with Icynene open cell spray foam insulation in a hot climate or southern US climate can help regulate HVAC efficiency and maintain improved indoor temperatures.















Ninety-nine percent of moisture travels through the air. An integrated open-cell spray foam insulation and air barrier system minimizes air leakage and, therefore, accompanying moisture. Diffusion represents only 1% of the total moisture flow. Diffused moisture travels through the sheathing and the insulation to the interior space where it is easily removed from the air by the A/C system. The moisture load and latent heat load is thereby dramatically reduced with the use of air-impermeable, soft foam insulation.

4 comments on "Using spray foam insulation in hot climates"

  • a

    I tried finding a local contractor by submitting my zip code (71322) at the top of the page, but "not found" showed up in the search results. I live in a 12' by 30' all metal house. Walls and floors sweat when it gets cold in the winter. Fiberglass was used in the walls before I moved in and causes a lot of condensation. What would you propose or recommend. Do you guys sell something a home owner can use himself. Any feedback is helpful. Thanks.

  • a

    Hi Trail6 - If you expand your search to 100 miles of your zip code (the search function defaults to 50 miles),there are two licensed Icynene within 56 miles. Both are able to provide you with an expert assessment of how best to insulate your home with spray foam insulation and address the condensation issue you're having with the fibreglass material. The two nearest contractors are: Rader's Insulation out of Lafayette (phone: 337-268-9353) and Butcher Air Conditioning (phone: 337-837-2000 web: www.butcherac.com). Hope this helps!

  • a

    We live in an historic house in Florida. We will be putting insulation in the house shortly. I have heard that there is a mold problem in the warmer climates like Florida if using spray insulation. Please advise. Thank you.

  • a

    Hi Sandy - Spray foam insulation has been used in Florida homes successfully for decades. Mold issues in any house, insulated with any product, are possible if a material (within a wall, floor or roof assembly) is consistently wet, warm and mold spores are present. A key strategy to prevent mold growth is to prevent moisture accumulation. Spray foam insulation can help in this regard since it acts as an air barrier and therefore prevents moist air from moving through it & into the assembly the foam is located in. Making sure that rainwater cannot get into a wall, floor or roof assembly is also a key strategy for preventing mold growth. If you have any additional questions, we're happy to talk with you. Call us on 1-800-758-7325.


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