Cool Energy House Status, January 2012

Work at the house is progressing as planned, and, as with any show demonstration home, the team is working quickly to prepare it for our events in February. Here’s a quick update of what has been happening at the CEH.

Insulation

At this point, all exterior walls are reinsulated with Johns Manville Spider insulation, a chopped fiberglass insulation. Under high pressure, the insulation was blown into wall cavities. Because of the innovative nature of the work, a few unforeseen obstacles were discovered and resolved. Unique challenges included the following:

  • Fireblocking in the 10-foot-high walls on the first floor blocked insulation from flowing from floor to ceiling, necessitating removal of horizontal bands of drywall and cutting 4-inch holes in the walls to provide access above and below the fire blocking.
  • The windows also provided a challenge. Holes needed to be cut under and above them for the insulation. 
  • Similarly, the second-floor rim joist required extra cuts for insulation. A slot was cut in the ceiling and spray foam was shot against the rim joist.

Exterior wall bands and holes needed to be cut to allow for the insulation to completely fill the wall cavity.

Slots were cut in the ceiling to allow for insulating against the second floor rim joist.

Structural Insulated Panels

The new three-car garage addition with a live-over “mother-in-law” unit was constructed out of structural insulated panels (SIPs) and is connected via a breezeway to the master bedroom suite addition.  

A 2x4 bolted and sealed to the brick provides a secure connection for the first SIP panel.

SIPs were used for both the new garage as well as the master bedroom addition.

The SIP building envelope was easy to install. Panels joined together quickly with inserted splines, glue and screws. BASF’s Neopor foam core gave the panels 20 percent more insulating value in the same space. The environmentally friendly Neopor material does not contain CFCs, HCFCs, HFCs or other halogenated cell gases.

Carpenters fit another panel to the gable-end of the garage unit. Panels plug into each other and are secured with a spline, glue, and nail system.

Black Neopor foam offers 20% better insulation performance over traditional, white expanded polystyrene (EPS) and 50% less material is used to make the product.

Panels fit over bolted sill plates and are nailed along the entire bottom of the panel, providing a continuous holddown path from sill to top of wall.

HUD Disaster Mitigation Sub-project

CEH is also participating in a program called “Opportunities for Enhancing Disaster Resistance—25 Retrofit Techniques in Existing Construction.” The program is financed by HUD and managed by the NAHB Research Center. With walls open and attics exposed, there was a golden opportunity to inspect for and enhance the building’s durability, as well as its resistance to disaster.

The HUD program provides a list of potential disaster retrofits for all parts of the country. In wind-prone areas, such as Windermere, Fla., many of the “fixes” aim to keep the building from being blown apart or away in extreme wind. Metal hold-down hardware from foundation anchors in the footings to continuous metal strapping and clips all the way to the roof create a “continuous load path” that resists uplift during extreme wind events. 

In the case of the CEH, built in the mid-90s, the builder took wind uplift very seriously. Inspection of bottom and top plates revealed a multitude of metal clips creating a serious attempt to construct a continuous hold-down path from foundation to roof.

An abundance of metal strapping and clips provide wall to floor attachment to create a contiguous load-path from the roof to the foundation

Metal clips at every stud provides shear strength against uplift

Wall to foundation attachment to create a contiguous load-path from the roof to the foundation

Metal clips even at cripples between floors maintain continuous load paths from roof to foundation

Other wind-mitigating solutions include reinforced garage doors, enhanced sealing around doors and windows with expanding urethane foam, elevating and anchoring HVAC equipment, and more. In the CEH, the addition of urethane insulation in the attic will provide further resistance to roof uplift.

Greening Orlando One Retrofit at a Time

You can make a good case that CEH is “green” simply by virtue of all its energy-saving measures. But with the guidance from the NAHB Research Center and Drew Smith, owner of Sarasota, Fla.-based Two Trails Inc., a consulting firm, CEH will meet the Bronze criteria of the ICC 700-2008 National Green Building Standard.

Interestingly, many building-material choices, including water-saving bath and kitchen fixtures, heat-pump water heaters and other Energy Star appliances, LED lighting and recycled-content countertops, seemed like obvious choices regardless of their “green” features. Excellent indoor air quality was guaranteed by specifying low VOC paints; no-formaldehyde products; and a Honeywell TrueDRY Dehumidifier, which actively removes up to 90 pints of water a day while filtering a constant supply of outside air. On the exterior, the new pervious pavers, cementitious siding and cool metal roofing also contributed to the certification. In addition, a soon-to-be introduced photovoltaic system by GE will deliver alternating current directly from modular, plug-and-play panels to the main panel and is installed by roofers, keeping electricians off the roof and installation costs down.

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