CALCULATION TIPS FOR BOILERS
Sizing a Boiler
BTU’s per hour output ÷ 33,500 = Horse Power
BTU’s input per hour ÷ 42,000 = Horse Power
MBTU’s (millions) per hour output ÷ 33.5 = Horse Power
MBTU’s (millions) input per hour ÷ 42.0 = Horse Power
Pounds of steam per hour ÷ 34.5 = Horse Power
Square feet of heating surface ÷ by 5 = Horse Power of a Fire Tube Boiler
Square feet of heating surface ÷ by 3 = Horse Power of a Water Tube Boiler
Finding the Percentage of Condensate Return (use conductivity readings)
Make-up water conductivity – conductivity of feed water ÷ by conductivity of Make-up water x 100 = % of Condensate Return
Finding water capacity for Hot Water Recirculation Boiler
Horse Power x 25 = water capacity for Hot Water Loop
