First fixing house with 3 bath rooms

[CAESAR32]

Hey if first fixing a house with 3 bathrooms, do you usually use 22mm to supply most of the hot and cold water. The hot waters from an unvented system.

 

[newbuildinstaller]

id go for 28mm for three bathrooms

28mm to first 22mm to second and third

or if they are all different directions 22mm to each

Depends on your flow rate though guna have to have a 28mm cold main to cyl cupboard.

of course all thats pointless if you have a 15mm cold main in to your house

 

[CAESAR32]

Is 25 mm mdpe to the house, the unvented cylinder only requires a 22mm cold feed.

 

[Richardthe3rd]

It depends on the dynamic mains water pressure & flow rate. Also, the number of occupants & simultaneous use of the bathrooms.
HTH

 

[CAESAR32]

Thanks you wouldn't do all 3 of 15mm though what ever?

 

[srhawksy]

Secondary recirc??? nice idea if you can?

 

[newbuildinstaller]

Thanks you wouldn't do all 3 of 15mm though what ever?

hahaha brach of in 10mm to your basins and wc!!

Its about pipe resistances too.

The 28mm cold main is because when it reaches the cyl cupboard it should split into a 22mm hot and 22mm balanced cold

22mm minimum!!!!!!!!!!!!!!!! to last bath/shower then 15mm

 

[Richardthe3rd]

id go for 28mm for three bathrooms

28mm to first 22mm to second and third

or if they are all different directions 22mm to each

Depends on your flow rate though guna have to have a 28mm cold main to cyl cupboard.

of course all thats pointless if you have a 15mm cold main in to your house

As a general rule of thumb, I'd do this. But your incoming pressure & flow would need to be established, as I stated.

 

[newbuildinstaller]

id go for 28mm for three bathrooms

28mm to first 22mm to second and third

or if they are all different directions 22mm to each

Depends on your flow rate though guna have to have a 28mm cold main to cyl cupboard.

of course all thats pointless if you have a 15mm cold main in to your house

As a general rule of thumb, I'd do this. But your incoming pressure & flow would need to be established, as I stated.

I was hoping/assuming that this had been checked and would support three bathrooms.

 

[CAESAR32]

is balanced cold often? used seen most people just cap it

 

[newbuildinstaller]

is balanced cold often? used seen most people just cap it

most people are wrong then.

The idea is to allow mixer taps/showers equal pressures either side. ITS THERE FOR A REASON!!

kitchen sink cold taken straight off stop tap then cold main straight to cyl cupboard then split hot and balanced cold

 

[Richardthe3rd]

id go for 28mm for three bathrooms

28mm to first 22mm to second and third

or if they are all different directions 22mm to each

Depends on your flow rate though guna have to have a 28mm cold main to cyl cupboard.

of course all thats pointless if you have a 15mm cold main in to your house

As a general rule of thumb, I'd do this. But your incoming pressure & flow would need to be established, as I stated.

Ask the local Water Inspector or Authority, they'll tell you & you may get a shock.....

I was hoping/assuming that this had been checked and would support three bathrooms.

 

[polesapart]

It really does depend on a number of factors -layout and distances involved as well as incoming pressure and flow. Likely simultaneous use and number and type of drawoffs.

15mm per bathroom might just do if low occupancy, 22 probably better, 28mm with secondary return luxurious/overkill depending on expectations.

If your not fazed by doing the maths

http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Pipe-sizing-basic-principles.pdf

and

http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Pipe-sizing-tabulation-method.pdf

 

[Norcon]

28mm is overkill for three bathrooms.
A secondary return is a good idea also.

 

[CAESAR32]

Do most people use balanced cold then even reps for unvented cylinders say most people don't use it.