A Mower-door-directed infiltration reduction pro cedure was field-tested on 18 homes in south central Wisconsin. The procedure, developed by the Wisconsin Energy Conservation Corporation, includes recommended retrofit techniques as well as criteria for estimating the amount of cost-effective work to be performed on a given house.

The procedure produced an average 16% reduction in air leakage rate. For houses recommended for retrofit by the procedure, 89% of the targeted leakage reductions were accomplished with 76% of the recommended expenditures. The retrofit costs represent a significant savings over costs of previous yet similar programs.

No statistically significant average energy savings were measured, as determined from pre- and post-retrofit furnace consumptions normalized to a common weather base. Measured savings for individual houses varied widely indicating that factors not considered either masked or reduced the expected savings. Possible causes are discussed. Whether results of controlled experiments could reveal causes for the lack of demonstrated savings in this and similar field tests is a point raised, but left unanswered.