pipe sizes for complete heating/DHW system

[pappasmurf]

Can someone pls help...... just bought a new house. After major works and extensions (Rear and Loft), (next year), will be an 8 bedroom, 4 shower room (no baths), 2 kitchens with full underfloor heating on all floors in the house.

The system will have 2 Worcester Bosch 24Ri (heat only boilers); 1 for the DHW, 1 for the Underfloor heating. No header tank.
I have already updated my mains supply from the street to 32mm poly pipe. The pressure is approx.3 bar and approx.20 lt/min.
There will be an indirect 300lt unvented megaflow cylinder feeding all the DHW (4 shower rooms,2 kitchens).

What i need to know is what size of pipework should i be feeding this circuit?.... i have always assumed that in plumbing, the bigger the better!... is this so?

I was thinking of supplying the cylinder with this 32mm MDPE pipe and then on the outlet from the cylinder feeding the house with 28mm MDPE and eventually reducing to all shower rooms/kitchens back down to 22mm and then further to 15mm. is this correct? as i am hoping to ensure good/reasonable flow rates to all services as possible espcially if more then 1 or 2 services are used at the same time.
will i also need an accumulator up in the loft conversion?.... if so what size pipework will i need for this aswell?

The underfloor heating in the entire property will be piped hot from heating manifolds using the "Wavin" brand.

 

[vern]

To be honest cant really say if reasonable or high as don't know what spec you talked about
Don't know size of house
Don't know spec of bathrooms
Make up of house ect

Difficult to say for reasons above....did £10.5K Inc VAT? Stage payments? Deposit?

 

[vern]

Gray0689 this is why i am also confused i need to get a comparison from other plumbers. the house "will" be a 7 bedroom (2 in the loft), 2 reception rooms, 2 kitchens and 4 shower rooms.
believe me i know this sounds like a mansion, but believe me its nothing of the sort! its actually quite small. when i mention 7 bedrooms to people immediately they think its massive!
the spec of each shower room is 1 shower head with 1 thermostatic valve, 1 basin, 1 toilet. and the plumber does not have to fit any of these facilities!... he just has to give the supply outlets for the builder to hook up.View attachment 8617

Bloody hell Papa you have saved all our fingers with that picture in the 1st post.....24i junior combi it is...job done!

 

[Gray0689]

Builder to hook up?
When did a builder become a plumber
Is your builder putting in soils wastes ect
Pay me cash and me and vern will come do it cheaper than your quote lol

 

[vern]

Builder to hook up?
When did a builder become a plumber
Is your builder putting in soils wastes ect
Pay me cash and me and vern will come do it cheaper than your quote lol

LMAO......I reckon Papa owes us £1k a piece already for consultancy work :wink5:

 

[pappasmurf]

vern yes inclusive of VAT.... didn't discuss payment options as yet....as we are only at the final payment quotation stage. no deposit though. this also includes the whole house underfloor heating; but all materials (to the last washer!) supplied by myself.

 

[Gray0689]

So he charging you £8750 before vat for labour only
Of fitting boiler cylinder all copper work all underfloor heating no sanitary ware no secondary return
Is soils and wastes included
Anything else??

 

[pappasmurf]

Gray0689 nope!...the builders been contracted to do that. thats inc. VAT so its £10500 all in!

 

[Gray0689]

Then I could come over and you could have me and vern do it for a little less
cash no problem lol that is if vern be up for it

 

[pappasmurf]

Gray0689 but you're in Ireland and Verns in Leeds!... unless your joking!... which i'm i'm sure you are!

 

[Gray0689]

No mate I live in Northern Ireland not Ireland
I'd be up for it if vern was I'd rough it at your house for a couple of weeks
But your builder would have to be on the ball as I'd be wanting it ready as I don't hang around insulation down quick for underfloor stand made for cylinder as I'd want to be doing everything before floor gets poured saves on visits

 

[Gray0689]

But that's only if you can't get anyone around you
And I like good materials witch is not cheap

 

[Gray0689]

Ps ask vern if he up for it first lol

 

[pappasmurf]

Gray0689 well i can't vouch for any builder as you must also know!...the cylinder will be going on the ground floor ontop of the concreted soild floor which will be the whole of the ground floor and then liquid screeded.
the materials that your refering to i would have to get anyway with this plumber of mine
see what vern says and give me a quote then

 

[vern]

Jeez Papa edit post 97 before someone quotes it!
lmao at Gray....when's it starting? seriously booked up to new year already just a few odd days here and there....2 nd baby due December, retaking all my ACS JAN......Feb any good?

 

[Gray0689]

February would suit me just fine mate