What are you thinking of doing?
Providing a hot water system to large domestic house
Mains pressure hot water?
Yes, off boosted supply tank and pump set
Is this a small hotel?
No
What is the usage?
10 people max (5 beds)
Will all showers be on at the same time?
Could be.
Bathroom - 1 large bath, 2 showers
Bathroom - 1 large bath
En-suite 1 - shower
En-suite 2 - shower
En-suite 3 - shower
You have high pressure water, so heat bank/thermal storage is the best way. One large cylinder unit can do and have
three DHW plate heat exchangers on the cylinder (dividing and ruling). One doing the baths only, highly unlikely two baths will be running simultaneously, and the showers split between the other two. Take the kitchen, etc of the bath plate heat exchanger. Shower is king, so dedicated plates for these.
The heat bank can do the CH directly using TRVs all around using a Smart pump. Or two CH loops off the cylinder to zone the CH to upstairs and downstairs.
The heat bank can be heated via electric immersions for backup, or full usage if gas prices go through the roof.
Heat the heat bank cylinder "directly" by boilers to give rapid recovery and use two small cheaper boilers in such a large house. This gives backup too. Control boilers with boiler sequencing for economical running. Look around there are many about.
http://www.warmworld.co.uk/026.html £190 + VAT
http://www.warmworld.co.uk/itemlist.php/clashist/-1,1,2/findclas/2/findchil/1
A heat bank can have a solar coil fitted in readiness for solar panels.
For further info see:
http://www.heatweb.com for info and sizing tools for cylinder.
Look at these. They do custom made thermal stores:
http://www.advanceappliances.co.uk/
Fit a magnaclean filter on the return on each CH loop back to the cylinder - essential.
Avoid unvented cylinders as you need an annual service on these. Heat banks give so much more in your situation.
