Boiler Sizing Calculator

Size heating boilers based on building heat loss, domestic hot water load, pickup factor, efficiency, and altitude derating.

Building Heat Loss

BTU/hr

Domestic Hot Water Load

BTU/hr

Pickup Factor

Combustion Efficiency

Altitude

Tab to move between fields

Gross Input Required

175,882 BTU/hr

Required Boiler Rating

175,882 BTU/hr

Net Output Required130,000 BTU/hr

Fuel Consumption1.76 therms/hr

Est. Annual Fuel Cost$4,221

How to Use This Calculator

Enter Building Heat Loss, Domestic Hot Water Load, and Pickup Factor.
Set Combustion Efficiency and Altitude.
Review Gross Input Required (BTU/hr) and Required Boiler Rating (BTU/hr).
Use Net Output Required (BTU/hr) and Fuel Consumption (therms/hr) to inform your decision.

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