Why no heatpump refrigerator combos?

[oz93666]

A big push for (air) heat pumps in the UK ... The outdoors unit has refigerant exiting the expansion valve at around -20C , it would be an easy afair to wrap a copper tube around this larger outlet copper tube from the expansion valve before it reaches the radiator , in effect creating a secondary heat exchanger with salt water pumped through it , this could enter the kitchen and enter the fridge freezer and another heat exchanger ... This may only be feasable where the outside HP is in close vecinity to the kitchen , but the saveings would be around 400KWHrs/year , and it would increase slightly the overall efficiency of the HP.