Interesting project, what are you making?
Well...
I've been doing a selfbuild project over the last few years, house is a mix of 1, 2 and 3 storey.
I have an open-vented heat bank (or thermal store, seems people use the terms interchangeably) on the ground floor.
I have UFH (8 zones) on the ground floor fed from the store, which is working fine.
Plan is to have rads on middle & top floors, fed from the store, but haven't plumbed these in yet.
However, the open-vented store means the F&E tank has to be very high up in the house, to be above the highest radiator.
I've not felt too comfortable with the tank being so high in the house, in case it ever leaks - the amount of damage water could cause running down 3 storeys doesn't bear thinking about, and no doubt if it did ever happen it'd be while on holiday etc.
So I thought that I could split the rad circuit by means of a plate heat exchanger, and run them as a pressurised system, while the store remains vented.
I can then move the F&E tank downstairs and have it just above the store.
Makes life much easier too if ever draining/filling the store, rather than running up & down 3 floors....
Also means a seperate system in terms of inhibitor, future flushing etc etc.
So there you go, the plate heat exchanger will sit near the store, and the primary will just feed from & return to the store.
Inspired by the efficient time & temp control I get from the UFH zones, I'm doing the same with the rads. So for example, if me or the Mrs is working from home during the day, we can just turn on a rad in the office without the rest of the rads running. I also hope to link in with the home automation system - using information from occupancy sensors around the house, so for example if there hasn't been any movement on the top floor in the previous X hours, don't run the top floor towel rails etc etc.
I'll have Heatmiser PRT programmable stats in each room, and individual valves controlling each rad. Also means the pump(s) will only run when a room is calling for heat. No central stat or bypass needed either.
Not decided whether to run them all off a manifold yet, UFH stylee, or a more conventional pipework run with 2-port valves to each rad - manifolds are much neater and have flow valves to allow easy balancing etc, but the central location means more pipework needs running. The more conventional system might be easier in terms of pipework, but the 2-port valves will probably be dearer than the manifold-style valves. Need to add up all the costs. Ultimately I don't think there's a great deal in it.
There, glad you asked eh
Keeps my mind active & gives me an excuse to buy a few new toys and learn a few new skills on the way !
