Air Handler Fan Electricity: With sealed ducts, there is a 20% reduction in run time, so electric consumption is reduced a similar amount. A typical distribution system fan draws about 600 W during operation, so 20% less run time means a reduction of 120 W per system. Assuming the standard 70% oversizing for a gas furnace (as a surrogate for diversity effects) then the reduction per house is 120 W/1.7 = 70W. The peak electrical savings are 70W per home x 8 Million Homes x 72%= 0.4 GW.

Residential energy end use estimates show 5.4% of total electricity consumption is for space heating (including both resistance and heat pumps). Therefore, a significant amount of electricity for electric heat can be saved from sealing and insulating ducts. It is very difficult to find information on peak direct heating load. However, if we assume half a million households with ducted electric heat, 15kW of heat per house, and a 1.7 oversizing factor, and that 60% of these electrically heated houses use ducts, then the total residential direct heating load through ducts is 500,000 x 15kW/1.7 x  60% = 2.6 GW. Saving 20% of this load, results in a saving of 0.5 GW.

The combined winter electricity peak savings are about 0.9 GW.