Pool and House ASHP (should I get both?)

[sw25481]

Oh wow, thank you for the great replies. Some answers to your questions

I have covered all my South East and South West facing roof in Solar Thermal and the remaining spots I have used for PV. I have 25 m2 of Solar Thermal (160x 58mm Evacuated tubes) and 28 m2 of PV, but some of that PV is less than ideal positioning. I have been chasing the manufacturers of the combined PV/Thermal units without any success but that would just increase my PV area, not my thermal. Solar Thermal is not enough to keep the pool at 29 Deg C that my kids tolerate so the boiler, (soon to be heat pump), takes up the slack.

Pool is 45,000 liters

House is just inside the M25 in Surrey. Heated envelope in the house is 128 m2 per story (252m2 in total). Average room heated temperature is about 19 deg c downstairs 17 upstairs. All underfloor

Yesterday I used 56 KWh of heat from the boiler (that is heat flow measured not gas consumed),and got nothing worth measuring from Solar Thermal. Best day this week was 4 kWh heat from the Solar Thermal and 29 kWh heat from the boiler. Obviously the pool is not operating at the moment.

This graph last January 2022 where I peeked at 120 kWh heat from the boiler and nothing from Solar



This is the Summer where on a good day I get 60 kWh from Solar and consume 6 kWh heat from the boiler but you can see on the cheek months (June for example) I can consume as much as 140 kWh in a day from the boiler much of which goes into the pool



I don't think 60 kWh from 25m2 Solar Thermal is that impressive. On the 29th September I generated 8.7 kWh of electricity from 12.92 m2 (0.67 kWh/m) of Solar PV and only 12 kWh heat from 25 m2 of Solar Thermal (0.48 kWh/m). PV is new so this is the only decent day I had both running. I will be measuring through the year because if the efficiency of thermal does not increase I would be arguably better off ripping it out and powering a heat pump with PV.

[Ken]

I used to have a 30kw oil boiler for the swimming pool and i switched to ASHP so i use 3kw for the 24kw? ASHP and 1kw for the pump. This matches the ouput of my PV quite well in summer.

My wife (skinny) also likes/needs it at 29-30C

I had the idea of using one HP both for domestic and pool but realised they are 2 different beasts.

I also looked at solar thermal as i already have that not used but concluded that this was putting in a boy to do a mans job and that the area of solar thermal would equal the area of the swimming pool and then what happens if the sun is less than optimum. I worked on PV being 20% efficient and thermal 80% (kw/m*2 )

And then the thermal does not power the pump either.

The ASHP i refuse to switch on if ambient temp is not 20+ and run 10.00 to 17/18.00 hrs. Whilst running (at high flow rate) there is only one maybe two deg C different between input and output temps and lifts the pool temp by c2C/day with cover on. The COP is operating in the 6 to 10 range according to the spec. so if you feed that into the above I kw sun energy into the thermal route is giving 0.8kw to the pool whereas 1kw to the PV is giving the order of 1.6kw to the pool leaving one to conclude that the solar thermal requires twice the area of the PV approx.

PV + HP + EV + HW diverter -brilliant.