Minimum pump HP required to meet a seven minute peak demand based on the number of bathrooms in the house when pumping from 15 feet suction lift. Values are averages and do not include higher or lower extremes. Includes flow rates for shower or bathtub, lavatory, toilet, kitchen sink, automatic washer and dishwasher 1, 1.5 Bathrooms: 1/2 HP for pressures between 20-40 PSI, 1/2 HP for pressures between 30-50 PSI, 1 HP for pressures between 40-60 PSI 2, 2.5 Bathrooms: 3/4 HP for pressures between 30-50 PSI, 1 HP for pressures between 40-60 PSI 3, 4 Bathrooms: 1 HP for pressures between 30-50 PSI |