Heat pumps will work down to 7c and give a cop of around 2-2.5 @7c any lower and you will be relying on the immersion heater back up and end up spending big bucks to stay cold.
Oil cost at the moment are around 6pkwh, natural gas 4pkwh, lpg 7pkwh and electric 13pkwh so electrical heating via ashp at 7c with a cop of 2.5 is going to cost more than ng but less than oil or lpg. At around 15c the cop will be in the high 3s for most ashp and so the savings are higher with running costs similar to ng with a condensing boiler.
Given that for most of the winter temperatures don't go below 7c ( in this part of the world) they should make sense if you combine them with the ability to switch between either oil or lpg but you're not allowed to do that and comply with mcs requirements
Oil cost at the moment are around 6pkwh, natural gas 4pkwh, lpg 7pkwh and electric 13pkwh so electrical heating via ashp at 7c with a cop of 2.5 is going to cost more than ng but less than oil or lpg. At around 15c the cop will be in the high 3s for most ashp and so the savings are higher with running costs similar to ng with a condensing boiler.
Given that for most of the winter temperatures don't go below 7c ( in this part of the world) they should make sense if you combine them with the ability to switch between either oil or lpg but you're not allowed to do that and comply with mcs requirements
