(adsbygoogle = window.adsbygoogle || []).push({}); 1. Heating element in an electric furnace draws 65amps on a 240v single phase circuit witha .98 ele.to thermal eff. The volume flow rate of air across the element is 1200CFM. the incoming air temp to the element is 65degree and the element temp is 75degree.

Whats the thermal power output in Btu/hr.?

2. Q=1.08xCFMxdeltaT and eff=Power(out)/Power(in)

3. Q=1.08(1200CFM)(72-65), Q= 9072 Btu/hr

Power(out)=(eff)(Power(in) P(out)= (.98)(9072) = 8890btu/hr

The problem is delta T , I am assuming 72degree the temp in but it says incoming temp is 65degree?? Im missing somthing here either the real delta T or Power In--somthinks not right??

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# Thermal power out

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