1. SIZING A WATER HEATER Determine use Choose appropriate sizing chart
Residential, commercial, school, restaurant, etc.
Choose appropriate sizing chart
See chart on last slide.
Determine number of persons
Total number of persons who will use the building
Recommended capacity of the WH tank (in terms of gallons per person per day)
Use a maximum of 2 gallons per person per day for office buildings

2. SIZING A WATER HEATER Tank efficiency Determine usable capacity
Rating of a WH tank in terms of percentage of hot water available at or near the system design temperature.
Assume a tank efficiency of 70%.
Determine usable capacity
Recommended capacity in gppd * no. of persons
Determine actual capacity
Usable capacity/tank efficiency

3. SIZING A WATER HEATER Find required recovery rate per person
Recovery rate is the water heating capacity of a water heater in terms of gallons per person per hour.
Use relevant chart (will be provided, if not in the textbook) to find out recovery rate per person.
Calculate total recovery rate
Total recovery rate = recovery rate per person*no. of persons

4. Fig (p. 610, Stein)