Big house, big job: mains off booster pump or gravity fed?

[mylocalplumber]

Okay so you may have seen my previous post regards to this but I'll just enlighten again.


Now I've never installed anything this big and just got my commercial ticket so bare with me. If I sound a bit amateur rest assured I will not start job till I'm 100% confident.


Got a 8 bedroom house big but not massive.


35 rads
2 bathrooms (standard fixtures)
1 en suite (standard fixtures)
5 additional basins (standard)
2 double sinks + standard utilities


Usage: 3-4 adults and 3 kids. 2 baths to run at same time interrupted was mentioned.


Currently there's a Keston c90 sealed heating with 2 cylinders open vented.


Boiler,tanks, pump to go in basement
20m static head
2.5 bar incoming
22+lpm flow rate


I want to put in;


2 GB-162 50kw cascaded
2 x 210l ACV invented cylinders
Softline 450l water softener


Now they've said that previously the mains pressure was not good enough so they had tanks installed and pumps put in for bathrooms.


As they suggested to me that they want he best system possible is it wrong for me to suggest sealing hot water, not installing PEV and running mains off a big pump?


I mean with the current static head and loads I reckon I need about 4.5 bar.


Anyone got any experience with this? I reckon it's the way forward but would like some pros and cons really. I could play safe and maintain the open vented side but is that really best?


Any responses appreciated.


Mo

 

[ShaunCorbs]

have a look at accumulators

 

[Chalked]

You don't need more pressure, just flow.
If they want the best. Fit a suitably sized break tank and twin inverter pump set.
Most manufacturers will size it up for you.

Fit the softner onto incoming main, but run a hard to a sink, outside taps and if you can, the boiler filling loop ( with 35 rads I would be fitting a auto top up)