In Example 16.10, we found that for typical temperatures of the hot and cold reservoirs,...

In Example 16.10, we found that for typical temperatures of the hot and cold reservoirs, the theoretical efficiency of a home heat pump can be quite large. Investigate the efficiency obtained with real heat pumps (i.e., do some research on the Internet). How does the efficiency of a real heat pump compare with the theoretical limit in Equation 16.28? What factors make the efficiency of a real heat pump smaller than this theoretical limit?

(reference equation 16.10 and 16.28)