Air to water HP - another crazy DIY project

rolion

Hi All,

Just got a quote with a hard to ignore price on a Panasonic a2w 6kw heat pump.

The question is how I'm I going to retrofit within my current setup and if creates any practical gain or advantage.

My "today" plan is:
- I have very good insulation,inside outside,acceptable level of tightness.
-installed and working gas boiler,solar panels,underfloor heating,radiators,300l cylinder.
- work in progress on 2.5kw PV panels
-complete heating automatic controls.

If I buy the A2W pump,with a new 170l dedicated cylinder for heating and UFH only,installed to run at a set parameters with powered by PVs day time and/or fallback or top-up by boiler trough three way valve and controller.

Installation is DIY,with location of HP on the back of the house,on top of the kitchen,above the gas boiler and all pipes.New 170l cylinder replacing washing machine place.

I'm I going out of common sense and practicality here !?

Thanks

murphaph

I wouldn't want that sort of complexity in my heating system to be honest. You'll be getting less value from the boiler you've already paid for too. Unless the boiler is near end of life or is particularly inefficient, I wouldn't introduce an alternative heat source.

Is your UFH and rads system even capable of running off a low flow temp heat source like a heat pump? If you have to jack up the glow temps it won't be efficient at all.

gctest50

murphaph wrote: »

.........
Is your UFH and rads system even capable of running off a low flow temp heat source like a heat pump?............

They do one for HT jobs, if you've old rads

http://www.aircon.panasonic.eu/GB_en/ranges/aquarea/ht/


For a house with high temperature radiators (for example, cast iron radiators), the Aquarea High Temperature Solution is most suited as it provides output water temperatures of 65 °C even at -20 °C.

Works down to -20°C

murphaph

Yeah but at what sort of efficiency?! I'd probably pull out my heat pump and install a high efficiency gas boiler before running the heat pump at 65 degrees glow temp.

gctest50

murphaph wrote: »

Yeah but at what sort of efficiency?!..........

Gruesome ! 2.2 something

kinda worth it though if there wasn't many years left in you, no mains gas and you didn't want tanks of oil that could be stolen

http://www.cdlweb.info/pdfs/Aquarea-G-Mono-High-Temp.pdf

rolion

Well,did some maths here.

Today's prices:
electricity: 15c
gas: 5c

Heat Pump: 6Kw
Gas Boiler: 30Kw

Of course,both have variable pump,demand controlled and very smart electronics.

So,if for the Heat Pump it's COP is at 3,it means there are no visible advantages to change from boiler to pump.