DOMESTIC WATER HEATER Russian patent published in 1999 - IPC

FIELD: domestic water heaters. SUBSTANCE: domestic water heater has hollow closed housing open from below for placing heater on domestic heat-transfer medium; it consists of two envelopes fitted one on other; outer surfaces of inner envelope has grooves whose walls are convex inward towards heat flow forming passages connected in succession in fitting outer envelope. Inner envelope may made from material possessing higher thermal capacity and heat conductivity as compared with material of outer envelope. Coil made from material possessing high heat conductivity and thermal capacity, for example from copper may be placed under upper wall of housing. EFFECT: simplified construction; enhanced economical efficiency; low cost. 3 cl, 5 dwg