Water Heater Sizing
Recommend water heater tank capacity by bedrooms and bathrooms using DOE occupancy-based sizing.
Recommended Tank Capacity50gal
DOE first-hour rating method
BTU Input Required30,000BTU/hr
Estimated recovery at 70 deg F temperature rise
General Sizing Reference
1-2 people30-40 galStudio or 1 bedroom / 1 bath
2-3 people40-50 gal2 bedroom / 1-2 bath
3-4 people50-60 gal3 bedroom / 2 bath
4-5 people60-80 gal4 bedroom / 2-3 bath
5+ people80-100 gal5+ bedroom / 3+ bath
Reference: DOE/ASHRAE water heater sizing method • Recovery based on 70 deg F temperature rise (50 deg F inlet to 120 deg F delivery)