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ASHRAE 62.2 Mechanical Ventilation Specs. ASHRAE Standard 62.2 (2010) Full Disclosure. Excerpt from page 56:
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ASHRAE 62.2 Mechanical Ventilation Specs
ASHRAE Standard 62.2 (2010) Full Disclosure Excerpt from page 56: • For any type of weatherization measure installed in accordance with this specifications manual, the contractor shall provide the homeowner with written documentation describing ASHRAE Standard 62.2 (2010) and recommendations for mechanical ventilation in compliance with this standard. • The document shall accurately list the benefits to indoor air quality of complying with this standard and the main steps that need to be taken to be in full compliance. * • The document shall include space for the homeowners’ signatures along with check boxes indicating whether they wish their contractor to fully comply with ASHRAE 62.2 (2010), or if they waive compliance. Problem: There is nothing to suggest informing the homeowner of the problems to be encountered in sealed homes with inadequate, or misused mechanical ventilation will result in improved outcome.
ASHRAE Standard 62.2 (2010) Full Disclosure Continued… Excerpt from page 57: • Homeowners who choose to implement mechanical ventilation measures that only partially comply with ASHRAE 62.2, or comply with previous versions of ASHRAE residential ventilation standards, will have to check the box indicating they are waiving compliance with ASHRAE 62.2 (2010) and sign the document. • A copy of this signed document must be left with the homeowner and another copy kept by the contractor. Problem: The focus is on liability – not on fully educating the homeowner to the problems
This is not a new issue • Research studies have consistently demonstrated that the culture, attitudes and behavior of homeowners/residents is the single most important factor in determining how well sealed houses function.
1999 WSU Report Washington State Ventilation and Indoor Air Quality Code Whole House Ventilation Systems Research Report John Devine Rick Kunkle Michael Lubliner Washington State University Extension Energy Program
Findings In Owners of New Homes: 58% of respondents had changed the settings on their timer
Findings In Owners of New Homes: The average period of mechanical ventilation was changed to 3.4 hours The VAIQ required the timer be set at 8 hours per day to maintain minimal air quality
Conclusion - in 1999 Even owners of new homes who are educated about the importance of mechanical ventilation, do not adhere to the prescribed ventilation regimen.
What’s Happening in 2011? Home owner manuals describing the need for whole house ventilation systems and operation have been provided to residents in new homes for over 10 years now. Home owners are no more educated about issues then they were prior to the home owner manual. And still we believe that educating the owner in a brief conversation is going to do the job?
The Trenches • What’s happening in the real world? • What about renters, second owners, and Public Housing?
Mark V. Hillman Telephone: 206.595.8569 Construction Project Manager Seattle Housing Authority
Seattle Public Housing Excerpt from Case Example House Report – Mark Hillman, Architect and Building Scientist • We observed the following: • This townhouse was built ca. 1999 (estimated since permit information not available from DPD), utilizing typical ‘speculative home’ materials and details for the times. The wall & roof assemblies include, from interior to exterior: • Painted gypsum board, insulation (blown-in fiber glass in ceiling (R-38) and fiberglass batts in the walls (R-19). Vapor retarder is assumed in the multiple interior paint coatings. • 2x6 stud wall framing, wall sheathing and WRB unknown, under cement fiber siding. • Roofing is composition shingles on plywood sheathing over pre-engineered trusses. • This is face-sealed type wall construction relying on excluding moisture at the exterior face of the siding. • Windows are flanged vinyl frames with insulating glass units.
Sample Site – February 8, 2011 Heavy condensation exists on the inside face of most windows. Organic growth and staining exists on window frames, sills, glass and other adjacent materials. Organic growth exists in the north wall of the northeast bedroom near the ceiling.
Sample Site, cont. The 24/7 operation bathroom fan, re-programmed by SHA yesterday, is not functioning so Jim reprograms it for proper operation. There is organic growth on the ceiling of the bathroom.
Sample Site, cont. No insulation exists over the gypsum board ceiling in the bathroom, and interior light is visible around the fan housing. Exhaust ducts are insulated, and appear to be connected to their roof terminations. A roof leak exists where the roof safety tie-off connection is fastened through the roof and sheathing. There is staining and organic growth on many areas of the roof sheathing and the truss members are damp to the touch.
Conclusions: • Conclusions and Recommendations: • Educate residents on use of exhaust fans to minimize moisture problems, organic growth and indoor air quality. • Equip the installed 24/7 fan with controls, secured to prevent resident disconnect or adjustment. • Replace gypsum board ceiling and treat surrounding areas to eliminate staining, prime/seal and paint. Use gypsum board products similar to Georgia Pacific’s DensArmor Plus® Interior Panels. Seal fan housing to the ceiling board, seal, prime and paint. Make sure an air barrier is established at the light fixtures to keep the bathroom moisture from entering the attic. • Clean, prime/seal and paint the stained areas in the northeast bedroom and all window sills and other stained areas. • Replace ceiling insulation over the bathroom ceiling, after cleaning and sealing the stained framing material. Verify if proper clearance exists between cardboard insulation baffles and the roof sheathing. • Evaluate the roof to determine if replacement, or simply cleaning and patching are required. Consider cleaning all roofs in this community if appropriate to extend their effective useful life. Make sure the ridge vents are functioning and the gypsum sheathing blocking the gable end vent is completely removed. • Condensation on the window frames inside the building, and inside the walls, drains to the base of the window rough opening and into the walls below, windows should be removed where siding is replaced. Reinstall windows with the typical SHA window installation details including metal foil clad self-adhering membrane tape.
Next Steps? Are we really interested in solving the problem, or is our primary concern for our own liability?
Other studies underway • We at Tacoma Power, with BPA funding, have undertaken a small study to examine both fan function 5 to 10 years post-installation. Results are expected in May. • DOE is currently testing 200 sites, monitoring for the impact of weatherization on indoor air quality.
Best Approach Oak Ridge National Laboratory Bruce Tonn and Scott Pigg ORNL Winter Case Study Underway
ORNL Weatherization Impact Study • Randomly sampled 80 Super-Public Use Micro Data Areas, with an oversample in high radon areas • Include approximately 550 single family homes in the treatment/control group study (~5/8 treatment) • Compare pre- and post- weatherization sampling periods