BTU Calculation for a fireplace-based heater

[JohnM24018]

An online seller claimed with an 80 Cubic Feet per Minute blower his output temperature was 350 degrees Fahrenheit from a fireplace heat scavenger. If you assumed his measurements were correct and the room temperature (input) was 70 degrees F. how would you calculate his gain in British Thermal Units? Thanks John

 

[russ_watters]

BTU/hr=1.082xCFMxΔT

 

[anorlunda]

• Specific heat capacity (Cv) air at 0°C and 1 bara: 0.7171 kJ/kgK = 0.17128 Btu(IT)/(lbm °F) or kcal/(kg K)