"Alan" wrote in message
...

Thanks, I often wondered about the efficiency of running A/C heat pump
systems all year to heat and cool a building as required.
I guess by the same token, the cooling process is reasonably energy
efficient also.

Heat pumps are very expensive to install. Running cost is the same as
natural gas. No need to cool domestic houses in the UK, if proper
insulation, shading, ventilation is done.