Nate Adams – The House Whisperer The Evolving World of Home Performance – Part 3: Building Science, IAQ & Insulation

Nate’s company Energy Smart started out as an insulation contractor for existing homes and has evolved into doing Comprehensive Home Performance retrofits. Their projects are somewhere between a simple attic insulation job and a deep energy retrofit. Nate the House Whisperer is also an author, blogger and maintains an excellent website with case studies about his projects.

Cellulose blown insulation after air seal is a favorite for DYI’s. Air sealing must be done first or air leaks will be hidden and unlikely to be found. Cellulose insulation has the tendency to settle leaving an 8″-12″ at the top of the wall cavity. To counteract settling insulation, insulation is pumped into cavities with a 2″ diameter hose manipulated up and down by the installer resulting in a densely packed application akin to putting “3 pounds of crap into a 2 pound box”. As the application is installer dependent; Nate provides financial incentives for insulation installers to hit blower door benchmarks. One hole is generally required per cavity. While the insulating process is messy; workers find insulation dust easy to wash off skin and clothing. Fire stops in wall cavities make insulating more difficult.

Fiberglass loose or blown. While less messy than cellulose, the residue is itchy. Fiberglass insulation is more prone to convection looping. Convection looping occurs indoors when warm air cooled by exterior walls falls downward. Using a blower door to create slight positive pressure in the house minimizes soiling.

Blown insulation is preferred over batts. He avoids batts during retrofits unless serious air sealing is done prior to installation. Houses without sheathing have 1″x10″ gaps.

Foamboard insulation options: XPS, EPS, Polyiso.

Prefers XPS because it doesn’t accumulate and hold moisture, is easy to cut and widely available. It can be used below grade and under slabs. XPS insulation available for wrapping the exterior of buildings reduces thermal bridging.

EPS the type of styrofoam used in cups. EPS holds more moisture and isn’t recommended for use below grade.

Polyiso is closed cell foam sandwiched in foil. It absorbs water and isn’t recommended for use below grade. The R-Value is known to degrade over time. Zip System R sheathing is Polyiso sandwiched in OSB.

Rock wool insulation batts, a commercial product, is fire resistant and suitable for use in firewalls and adjacent to chimneys.

Boutique insulation such as denim, wool, straw bale, etc. is hard to source. Traditional materials provide better results.

Closed cell spray foam while more costly controls air, heat and moisture simultaneously. It’s impervious to water and the best air sealer having an R-Value of R-6/R-7 per inch. Houses must be unoccupied when closed cell spray foam is applied and for an additional 48 hours after. He prefers to have the product applied in warm weather. He uses Foobot’s to monitor the IAQ in the houses he works on and finds it may take 2 weeks to return home to preexisting VOC levels.

Aircrete insulation is cementitious concrete. It is Nate’s preferred injection foam product.

Urea formaldehyde foam shrinks considerably over time. He opines there is no place for it.

Nate has issued a before and five year after blower door performance challenge and hasn’t had any takers.

What about air quality? When you tighten a home, you lose natural ventilation. Naturally ventilated houses can be unhealthy due to contaminates found in cavities. Tight houses need the addition of fresh air that has been filtered and dried. Tight houses should add a dehumidifier. It’s important to continually monitor what’s happening.

Tipping Points:

   Dew points are higher.

   Heavy rains are increasing.

   HVAC dehumidification is down.

   Increased use of engineered building materials.

   Increased shading.

Creating High Success Projects requires balancing: goals, house needs and budget.

The International Sanitary Supply Association show is truly and international event with attendees and exhibitors from around the globe.

Cleaning and maintain buildings is a key component of IEQ. When operating budgets get tight cleaning and maintenance are often reduced.

Richard Shaughnessy, PhD presentation “Do fresh air and clean classrooms have anything to do with our children’s health?”

The fireside chat with George W. Bush, exceeded expectations. President Bush is

sincere, humble, humorous, and self-effacing. Powerful people need to be held accountable. Power can be addictive. The pain his children endured seeing their father publicly criticized. He loves painting.

Thanks to Jeff Cross, Cleanfax magazine and Chris Mundshenk, BSCAI for their invitation.