GSW Signature Series Electric manual Reference Guide for Water Heating

Appendices

Reference Guide for Water Heating

One US gallon of fresh water weighs 8.333 lb.

Water expands 4.34% heated from 40o to 212o F.

1 BTU = Amount of heat required to raise the temperature of 1 lb. of water 1o F.

Recovery GPH =	KW x 3412
(Electric)	8.33 x ΔT
Recovery GPH =	Input x Efficiency
(Gas)	8.33 x ΔT

Req. BTU Input = Water Heater Capacity x 8.33 x ΔT % Efficiency

First Hour Draw (FHD)

FHD = (Storage x % Efficiency) + Recovery

%of hot and cold water needed to be mixed to obtain a desired temperature

Hot water percentage = M-C

H-C

Cold water percentage = H-M

H-C

Water C = Cold Water Temperature

H = Hot Water Temperature

M = Mixed Water Temperature

%Efficiency = GPH x 8.33 x Temp. Rise BTU/Hr. Input

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