Energy Conservatory Articles
Minnesota's Experience With Enhanced Low-Income Weatherization.
(from TEC UPDATE - Fall 91)
In 1988, the State of Minnesota embarked on an aggressive project to improve the cost-effectiveness of the statewide low-income weatherization program. The M200 Demonstration Project redesigned traditional crew protocols by incorporating a number of enhanced weatherization procedures developed by various programs around the country. The results of the demonstration showed that overall program cost-effectiveness could be improved dramatically, while at the same time devoting more resources to health and safety testing and client education.
Key procedures incorporated in the M200 Demonstration included:
- Blower door guided air sealing procedures which enabled crews to concentrate their efforts on the most cost-effective air sealing opportunities.
- High density blown cellulose was used to increase the effectiveness of wall insulation retrofits as well as to seal hidden inaccessible bypasses found at key construction junctures.
- Sealing duct leaks and correcting household pressure imbalances in forced air distribution systems was a high priority.
- Combustion safety tests for proper draft, carbon monoxide and worst-case house depressurization were preformed on every house.
- A client education component was developed which included client training on lifestyle and behavioral impacts on household energy use.
Compared to a 1986 study of the Minnesota Weatherization Program, the M200 Demonstration increased average household energy savings by nearly a factor of two. A 120 house sample of M200 clients showed an average adjusted energy savings of 17.9 percent (255 ccf/year) compared to 10.9 percent savings (117 ccf/yr) found in the 1986 study. The total cost (retrofit plus administration) for the M200 houses averaged $1,571 with a simple payback of 12.3 years. The 1986 program showed average total costs of $1,450 per house and a 24.8 year payback.
Blower door measurements before and after work was completed showed an average reduction of 36 percent in air leakage for the M200 Demonstration. Average pre-retrofit leakage was measured at 2,433 CFM50 while average post-retrofit air tightness for the M200 houses was recorded at 1,563 CFM50. Blower door test results were not available for the 1986 Minnesota Weatherization Study.
An often overlooked but extremely important facet of a successful weatherization program is providing conditions for the workers to perform at their optimum level. An integral aspect of the M200 Demonstration was to provide auditors and crews with a decision making process which allowed them the flexibility to do what made the most sense for each house. The blower door gave them feedback which encouraged them to strive for better results. The problem solving nature of the crew and auditor protocol gave crews greater initiative and led to higher performance and job satisfaction.
Experience gained from the M200 Demonstration is now being used to redefine the entire approach to low-income weatherization in Minnesota. The new program protocol and procedures are scheduled to be implemented statewide by this fall. A two-volume training manual will be available from the State of Minnesota Department of Jobs and Training later this year.
