People don't tend to like change. In particular when it isn't a seamless transition with preferably an improvement for no cost...
Back in the real world and being generic.
Did he have a heat calc
Has he addressed insulation
Both my and Fintrays heat curves were set at 0.6. Fintrays is a 10kW, mine is a 7kW. The heat loss calc defined these specs. We both found 0.6 to be too high. Fintray is running at 0.4 now as am I.
The fella could use 0.6 to.0.4 setting as a ballpark to play in. Pick one, pick.an internal temp and see how often the heat pump kicks in and out. Is it too hot, too cold, raise or lower as req'd and test again. Tell the fella about low & slow. He want the heat pump running at as low a flow temp.as he and his family are comfortable to live in. It's not a race and it's not for misers, or at least shouldn't be.
The idea is to heat the whole house to a decent living temp and let the whole home be a storage battery. First part takes 5 days to a week, to truly bring every.surface and material up to temp takes a few weeks. I mean it ALL...
This leads onto question.of costs which leads me back to point 1 & 2. That should help. Tell.him.to get out of stop/start mentality. He'll feel better.
Our thermometer on smart thermo for hp is set to 19, we back it off to 18.5 when solar gain kicks in thru the day. The wbs goes on in evening and runs low & slow. It still knocks the big lounge heating up to 22 and bleeds heat throughout the house so the HP.doesnt run. We are 75% down on log use. We have setback at 19.5 degs in the rest of the house for low rate thru the night and back down to 19degs from 05.30 onwards.
Seems to be working well for us.
If the fellas got any questions he's more than welcome.
I told him that the idea was to set the temperature they wanted and then let the hp run to maintain the temp and not to turn it on and off as they would if it was lpg gch. I will get the name of the hp and see if anyone here can give us some pointers regards set back for night time and some of the clever stuff Fintray and JB and others are discussing regards curves and run modes to try and help the guy fathom it out.