Hello,
So I want to add a solar thermal system to my existing Worcester bosch greenstar but don't want to lose the functional benefits of the combi boiler.
I'm proposing to install the solar collector on the side of the house in a position that will enable gravity flow to a 200litre tank just above on the inside. Then a vent tank and overheat radiator in the roof to prevent boiling the system. Control valve would open the radiator in power failure.
Then the bit that I'm not sure about. I have a bosch greenstar boiler. I want to pass the incoming cold feed through a heat exchanger with water from the tank to pre heat the cold before entering the boiler.. The cold is very cold here even in summer. The greenstar is apperently modulating so could it accept the water being lifted up to say 35-40c or would this be a problem? If it is I could put the heat exchanger after the boiler and lift the hot water temp up higher and use TRV on all my taps.
I could also do a similar heat exchanger tapped into the radiator circuit return with pipe sensors to detect if the cylinder temp is above my rad temp and if so it would activate and heat the boiler return.
Reason why I'm looking at doing it all this way is I feel if causes the least disruption to the existing pipework and seems pretty low cost. Diagram to follow
So I want to add a solar thermal system to my existing Worcester bosch greenstar but don't want to lose the functional benefits of the combi boiler.
I'm proposing to install the solar collector on the side of the house in a position that will enable gravity flow to a 200litre tank just above on the inside. Then a vent tank and overheat radiator in the roof to prevent boiling the system. Control valve would open the radiator in power failure.
Then the bit that I'm not sure about. I have a bosch greenstar boiler. I want to pass the incoming cold feed through a heat exchanger with water from the tank to pre heat the cold before entering the boiler.. The cold is very cold here even in summer. The greenstar is apperently modulating so could it accept the water being lifted up to say 35-40c or would this be a problem? If it is I could put the heat exchanger after the boiler and lift the hot water temp up higher and use TRV on all my taps.
I could also do a similar heat exchanger tapped into the radiator circuit return with pipe sensors to detect if the cylinder temp is above my rad temp and if so it would activate and heat the boiler return.
Reason why I'm looking at doing it all this way is I feel if causes the least disruption to the existing pipework and seems pretty low cost. Diagram to follow