Patent ID: 7620302
Filing Date: 2009-11-17
Classification: F24H

Abstract:
1. A high efficiency peak-power reducing domestic hot water heater comprising a closed tank having a predetermined water holding capacity, a hot water outlet in a top end wall of said tank, a cold water inlet in a side wall of said tank adjacent a bottom wall thereof, three spaced apart resistive heating elements projecting substantially horizontally in said tank, said resistive heating elements being positioned to provide efficient water temperature stratification of water within said tank, a bottom one of said resistive heating elements extending in said tank spaced slightly above said bottom wall, a middle one of said resistive heating elements extending in said tank at a level which is calculated at approximately an average maximum water consumption volume drawn during a peak power demand time period, and a top one of said resistive heating element extending between said middle element and said top end wall of said tank, said top resistive element having a large power rating of between 3800 to 4500 watts, said middle resistive heating element producing a heat barrier in said water within said tank at the level of said middle resistive heating element in the range of about 140° F. to reduce the propagation of harmful bacteria to said hot water supply in said top portion of said tank, said middle resistive heating element being disposed above mid-level of said tank, said bottom resistive heating element having a low watt density rating in the range of from about 15 to 30 W/in 2 , said bottom heating element having a life rating which is higher than said middle and top heating elements.