Planning Bill of Materials for Loft conversion - Help

[brettjmcc]

Hello All,
First post, so apologies if its been covered tried the search and couldn't find an answer.

I am planning a loft conversion (Planning already approved as part of some bigger plans a few years ago). As part of it I realise I need to change the boiler and current set-up as it will interfere. Basically the boiler has had it (a Suprima 60), or to be correct I've had it with the boiler, as it always trips ut despite going through the usual checks on PCBs etc. So that will be a new item. So its a remit for a new system.

The house will have a 11 rads and now because of this 2nd expansion will make a 5 bed with a bathroom with shower and 2 ensuites.

I have looked into unvented option so I could use mains pressure, but I won't be able to get a 22mm feed to the tank that I have been advised is needed.

So I think I will have to go to a gravity system with a negative head pump. Using my Dad's experience with his loft conversion I will use a Stuart Taylor Monsoon pump.

However, how do I go about speccing the rest of the system to make sure any plumber quotes are not trying to rip me off. How do I work out coffin tank sizes and new hot water tanks and also recommendations on a boiler.

Thanks in advance
Brett

 

[ChrisR]

Stuart Taylor Monsoon

I wouldn't. NOISY!
I have one, but there's only 2 of us. Look at something like a Lowara Multi-stage inverter driven pump. Variable speed. Will cost more (perhps £800 with pressure vessel and hose kit) but almost silent on low flows, and much less din than a Monsoon flat out. You set the pressure, so you get a "flat" pressure curve. Say 2.5 bar (more than enough) at 0.5 litres a minute or 50 litres a minute. Monsoons just go on/off, and pressure drops with increased flow.
Tank = probably 400 litres. Float switch to turn pump off if it runs too low.
Fit two float valves ( ball cocks) so it fills as fast as possible.
Google for suppliers, you can get all sorts of shapes. Even if they don't say so, most suppliers will do you a BLACK one which you need to deter algae.
Unvented - add your needs up. Probably 250 litres or so. Look at Oso if you need a short fat one. "megaflo" are overpriced.
An alternative to a pump + UV is an accumulator, as long as you have good mains pressure and a reasonable flow inthe loft - have you measured it??
I'd use a pump though.

 

[brettjmcc]

Thanks, I've measured the mains pressure off a simple gauge from Monument, its 3bar and even with the kitchen tap going and also toilet being filled didn't drop below about 2.3bar.

Thanks for the advice on the pump will look into that.

 

[brettjmcc]

Chris, any tips on which model to look at? Thanks

Brett