Hi,
I have recently emigrated to the Czech Republic, into a house that has a relatively old boiler with sealed CH and an 100 litre unvented cylinder for the DHW. The system is great as there is plenty of hot water at a good pressure.
As the system is old (1998), and my water comes from a well (and therefore quite hard) the system needs replacing as I imagine it is fairly clogged up and inefficient.
As I would like to add a wood burning stove and solar panels to the system, my research tells me that an vented thermal store would be a good idea, due to the added complication of adding these things to a sealed system, ie what happens in the event of power cuts, component failures etc, although I believe wood burners and unvented systems are more common in europe and there are solutions to all these issues.
My main reservation with a thermal store is, and please correct me if I am wrong, is that as the hot water is heated on demand, if someone is having a shower upstairs, and someone opens the hot tap in the kitchen, this will increase the flow though the plate heat exchanger and therefore the temperature of the hot water as it leaves the heat exchanger will be lower and the person in the shower will experience a temperature drop. Is this the case?
It seems to me that the advantage of the unvented cylinder is, as the hot water has already been heated, that the temperature of the hot water does not drop if you open two taps... as long as you dont empty the tank! The only disadvantage I can see of the unvented cylinder is the added complication of adding things like wood burning stoves and solar panels, and integrating all the systems so that they can be used to heat the CH and the DHW. This process seems much simpler with a thermal store.
Any advice would be greatly appreciated.
I have recently emigrated to the Czech Republic, into a house that has a relatively old boiler with sealed CH and an 100 litre unvented cylinder for the DHW. The system is great as there is plenty of hot water at a good pressure.
As the system is old (1998), and my water comes from a well (and therefore quite hard) the system needs replacing as I imagine it is fairly clogged up and inefficient.
As I would like to add a wood burning stove and solar panels to the system, my research tells me that an vented thermal store would be a good idea, due to the added complication of adding these things to a sealed system, ie what happens in the event of power cuts, component failures etc, although I believe wood burners and unvented systems are more common in europe and there are solutions to all these issues.
My main reservation with a thermal store is, and please correct me if I am wrong, is that as the hot water is heated on demand, if someone is having a shower upstairs, and someone opens the hot tap in the kitchen, this will increase the flow though the plate heat exchanger and therefore the temperature of the hot water as it leaves the heat exchanger will be lower and the person in the shower will experience a temperature drop. Is this the case?
It seems to me that the advantage of the unvented cylinder is, as the hot water has already been heated, that the temperature of the hot water does not drop if you open two taps... as long as you dont empty the tank! The only disadvantage I can see of the unvented cylinder is the added complication of adding things like wood burning stoves and solar panels, and integrating all the systems so that they can be used to heat the CH and the DHW. This process seems much simpler with a thermal store.
Any advice would be greatly appreciated.