#525 HVAC Afternoon NCEES 2008 Sample Exam

[JoeysVee]

This is really an easy problem but the thing I don't understand is why include the friction hp in as the condenser Qout? Seems like the condenser Qout would be 23.2*12000 +33.5hp*2545(conv factor) = 363,657 btu/hr The friction hp in the compressor is not taken out as Qout in the condenser is it? Why did the solution include the 5.75 friction hp? I don't understand this. :brickwall:

 

[POPAC]

This is really an easy problem but the thing I don't understand is why include the friction hp in as the condenser Qout? Seems like the condenser Qout would be 23.2*12000 +33.5hp*2545(conv factor) = 363,657 btu/hr The friction hp in the compressor is not taken out as Qout in the condenser is it? Why did the solution include the 5.75 friction hp? I don't understand this. :brickwall:

Check on the equation they say Qcond - condenser and Qevap- evaporator and work done by the compressor plus some friction .

 

[JoeysVee]

Check on the equation they say Qcond - condenser and Qevap- evaporator and work done by the compressor plus some friction .

Yeah NCEES doesn't have very good solutions! They do not eplain with they include friction...seems to me like they should not include friction.