[Greenbuilding] Understanding Heat Pumps

[Dan Antonioli]

Keith,

As I research heat pumps and read the discussion here, there are a  
few issues that you might be able to clarify.

First, in a mild climate where no air conditioning is necessary, can  
an air-source heat pump be employed that only functions to heat?  
Seems like most of the units I've seen are designed to also cool,  
which is redundant when you don't need cooling.

Second, what is their efficiency or "coefficient of performance?" In  
other words, how many amps or watts will they draw? Remember that  
this discussion started with the "all electric house" theme.

Third, can heat pumps be integrated into a forced air ducting system?

Finally, how cost effective is this approach to whole house heating?

Thanks in advance.

Dan