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ASHP + two cylinders - possible?
I'm not a heatgeek professional (although I am a geek 😉 )
The heatgeek "pink cylinder" is a thermal store with a coil inside. The water from the heating circuit is on the tank side, the potable water from your water supply is inside the coil. The coil is very long and has a large surface area so it will heat the water as it flows through the pipe. If your central heating system has a suitably sized accumulator you won't need an extra one for the "pink cylinder".
The design is similar to what I've seen installed on solid fuel systems, although it's colour is a little brighter!
The hot water inside the cylinder would need to be a relatively high temperature, probably the same as your actual hot water tank. So you'd need a control scheme that could divert the central heating flow into the cylinder and increase the heat pump flow temperature.
I might suggest if you're concerned about hot water flow then you might want to make sure you have back up immersion heaters in your main water tank. I have a doubts that a heat pump is really to way to provide lots of hot water and heat a building at the same time. You could install two heat pumps, one for space heating and one for water heating. That would make the controls much easier since the two cylinders would be zones off one heat pump.
This might be an interesting read for you:
Regards
Bob
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