How to do Air Sealing: The Expert Energy Show - buildaroo.com

Terry shares with us that air sealing is often overlooked in floors and attic, and if there are air leaks with insulation, the insulation value just plummets. On his mini advanced framing model, he shows an example of spraying foam around piping that is protruding through the wooden frame, the ceiling plate and wall cavities. Having holes in the wall cavities allows free air movement between them, and in energy audits, one often finds air leakage in these areas. With hundreds of thousands of holes like these, the home is prone to lose heat and energy. In the crawl space, the same principle applies; if a hole is drilled through the flooring for plumbing, spray foam should be applied in the space between the piping and circumference of the hole drilled.

If there is air leakage between the sill plate and foundation, chemicals used to treat plants or shrubbery near ground level outside may potentially be blown and spread around the house. If one notices carpet stains on the inside of walls, this means that the carpet has been acting as a filter for air entering the house. Foam or caulking can be used to fill in these spaces. Terry shows off the spray foam gun he uses to fill in the gaps, and he likes his gun because the foam canister can be refilled whereas the canisters are tossed after use with the more traditional guns.

Category:

Science & Technology

Tags:

• Air Seal
• air sealing
• building
• green building
• insulation

[rsmithCWA]

@d1incharge Good point, you shouldn't do air sealing without a blower door to test ventilation rates and to make sure the HVAC is providing enough air.

[rsmithCWA]

@d1incharge Natural ventilation means getting random amounts depending on how windy it is outside. You also get air supplied from the weakest, leakiest part of the house like your basement and garage. Not exactly fresh air! For this reason ASHRAE doesn't recognize air leakage as a ventilation strategy any more.

[d1incharge]

And when a customer lets a filter go too long like they always do? You can maintain a controlled ventilation, 99.9% of homeowners won't know what the hell we are talking about. It is a dumb risk to trust any moving part when it comes to your family/occupant health, all moving parts fail. Circuit boards that run controllers fail. Energywise if you don't use an hrv/erv, it costs more to mechanically ventilate, tiny amt more, but still, for what? Filter outdoor air, the standard for good air?

[Bigrignohio]

@d1incharge The goal is not no air exchange, it is CONTROLLED air exchange by the HVAC system. Remember the the "V" in HVAC is "ventilation". Controlled ventilation will take care of moisture, CO2 and any chemical offgassing (and any modern home should be build with low-voc materials anyway).

[Bigrignohio]

@erazman Actually any GOOD builder will air-seal all openings. Stack effect can cause large quantities of warm moisture-laden air to move through it. Heat loss PLUS possible condensation in walls and on sheathing. Can you say MOLD?

[erazman]

god damn old timers. they are still stuck in the days when everybody was ejaculating all over their air tight homes. who the hell puts foam in the holes. u guyz are old goofs

[d1incharge]

what about when your kids play in the roses you just sprayed? The whole air quality safety thing is just bogus, your carpets and pads create more dangerous air than outside air. It is the same as saying dont open your windows on a nice day! Dont forget to mention, there is a such thing as a house the is TOO TIGHT. If you air seal, it is a good idea to have your home tested for air change rates to make sure your not hoding in dangerous VOC's from carpet/paints/tiles/pads/furni­ture/electronics.