Help please with designing incoming mains size.

[Sharp Point]

Evening peeps,
Ive been asked to carry out the work on a 7/8 bed new build, now usually when i do new builds the incoming main is never to far from the road, so the builder/s usually deal with that. This job is for a private customer, who has literally built the house himself and i must say its fantastic. Every bedroom has a en-suite ( loo, basin and mains thermo shower) there is a master bathroom ( bidet, wc, basin and bath)
The house has block n beam on ground and first floor, 2 bedrooms in the attic, UFH throughout every floor, Unvented hot water, secondary hot water and ground source ( slinky's already installed in his fields)

Right, the new dwelling is 165 metres from the road, right next to the old farmhouse they're living in at the moment. The farmhouse currently has a piddly 20mm old style mdpe supplying water and the pressure is pants, and yes i've done the obvious checks. He has applied for a new connection with anglian water, who have sent out a pdf form via email to fill in, the custard has filled out the majority, but has asked me to help answer some questions, as i've never completed a form before, i'm a little bit stumped........

Is there a possibility you good folk could help? right here goes....

custard has tick yes to a supply larger than 32mm, then they want to know

1) maximum daily demand in m3 a day- total
2) maximum instantaneous demand litres per second - total
3)on site storage- litres
4)Percentage of daily demand supplied via storage- total / domestic

Is there a rule of thumb for number 1, guesstimated number of wc flushes, cooking, bathing?
There is no instantaneous, its stored hot water for number 2
Is this for hot water or cold water in general? number 3
number 4.......not a clue.

Me and the custard have agreed on a 300 litre unvented hot water cyl ( enough to accomodate his self and wife, children when they come home from uni)

Thanks

 

[joni os]

Anglian Water recommend 50mm pipe for runs 100 - 800 metres. I suspect the other information is to confirm all new equipment complies with water efficiency regs.
Google Water efficiency in New Builds.
They may also wish to flush, pressure test and possibly chlorinate new main.

 

[Chalked]

Looks like a nice job!

I'm dong a similar property, but I'm way bigger than what your proposing. 300 litres would do three bathroom property, but it's mo good for the other 5!

Why put a system in that will not perform when all bedrooms are occupied?
If you work on a low figure of 20litres a min per bathroom excluding other hot outlets, the hot water will run cold after less than 3 minutes!
I also would be fitting a pump set as you can't guarantee the flow rate needed from the water main.

 

[kozak1968]

Booster set and header tank would be best. As Chalked says you want the system to perform to expectations. A 32mm main may not deliver enough for the amount of water you may require.

 

[Sharp Point]

300 litres was his suggestion as the house will only really ever be home for two people. We both agree that working on the basis of 50/60 litres of hot water per person for two people that 300 would be ample. To have a bigger cylinder sat there losing heat seemed pointless, bearing in mind it's going to be heated by a electrickery gobbling ground source heat pump.

 

[Sharp Point]

Booster set and header tank would be best. As Chalked says you want the system to perform to expectations. A 32mm main may not deliver enough for the amount of water you may require.

It was mentioned by myself, but there is nowhere to house any tanks and the purchase / maintenance costs, soon put him off. It's a nice pad, but he does seem to be doing it to a budget.

 

[Sharp Point]

Anglian Water recommend 50mm pipe for runs 100 - 800 metres. I suspect the other information is to confirm all new equipment complies with water efficiency regs.
Google Water efficiency in New Builds.
They may also wish to flush, pressure test and possibly chlorinate new main.

Yes, your quite correct on that, but initial talks between custard and anglian water have resulted in a ' we don't/ won't fit a 63mm connection'

 

[quality]

How old is the ground source heatpump ?

 

[Sharp Point]

How old is the ground source heatpump ?

Its being designed as we speak by 'Plumb centre's renewable dept' i've no idea on what they're going to pull outta the bag? I've sent all plans via email to them, as i want no comeback if things aren't right.

 

[quality]

If its designed correct it will nock spots off oil, lpg and natural gas. 300 litre does seem a little small. What is the road supply pressure

 

[Chalked]

I can understand doing a house like that on a budget and saying they will only be using the house mostly for two people.
I beggars the question, why have 8 bedrooms with en- suites??

 

[Sharp Point]

If its designed correct it will nock spots off oil, lpg and natural gas. 300 litre does seem a little small. What is the road supply pressure

I/ He hopes so, we've heard so many horror stories. Standing pressure is 2.2, dynamic is 1.3 and has a flow rate from existing outside tap straight off old farmhouse incoming mains of 11 l/m

 

[Sharp Point]

I can understand doing a house like that on a budget and saying they will only be using the house mostly for two people.
I beggars the question, why have 8 bedrooms with en- suites??

I know, i know..... we've discussed things at length and this is the compromise, it was hard enough to convince him to get a new cold mains connection, he wanted to just use the piddly old mdpe supply.

 

[Sharp Point]

Right been doing some research on tinternet, seems an average person uses about 150 litres a day......does that sound about right?

quick back of a beermat calcs,

8 x 150 = 1200 litres = 1.2 m3 water a day, when full occupancy.

 

[quality]

What electric supply has the building got?

 

[Sharp Point]

What electric supply has the building got?

Until 'Plumb centre' pull they're finger out and come back with the heat loss calcs/ heating load, then we can decide whether it'll need a 3 phase supply.....if thats what your meaning my friend.

 

[quality]

Until 'Plumb centre' pull they're finger out and come back with the heat loss calcs/ heating load, then we can decide whether it'll need a 3 phase supply.....if thats what your meaning my friend.

Yes mate that is exactly what I mean. It will need 3 phase without a doubt . if there is concern over cost for a water main, tell him to get ready for the electricity supply

 

[Sharp Point]

Yes mate that is exactly what I mean. It will need 3 phase without a doubt . if there is concern over cost for a water main, tell him to get ready for the electricity supply

I think he's sort of prepared for that........i think.

 

[Cardiff Plumber]

If you have a pump room, 2no 50 gallon tanks break tanks, 1" ball valve, Grundfos booster pump, here: CM, CME BOOSTER | Grundfos and ususal additional products, check valves, associated valves, etc, pipe sized accordingly.

Done this on many hotels and bespoke projects! Works every time when there is low pressure and bad flow rate.

 

[Sharp Point]

,

If you have a pump room, 2no 50 gallon tanks break tanks, 1" ball valve, Grundfos booster pump, here: CM, CME BOOSTER | Grundfos and ususal additional products, check valves, associated valves, etc, pipe sized accordingly.

Done this on many hotels and bespoke projects! Works every time when there is low pressure and bad flow rate.

Thanks for that 'Cardiff plumber' from your experience, what height do the cwsc have to be above the pumps?

 

[Cardiff Plumber]

,

Thanks for that 'Cardiff plumber' from your experience, what height do the cwsc have to be above the pumps?

They dont, they can be on the same level, just use double check valve.

 

[josh]

You would never satisfy 8 bathrooms at the same time with just the main, will always need a booster arrangement and remember the main may only be 32mm but aslong as the flow rate is enough to satisfy the break tank your ok. Also remember your not meant to be pulling more than 12l min direct from the main from the water boards point of view so sometimes when you fill out the water connection form you have to play with the figures a little.

 

[Sharp Point]

You would never satisfy 8 bathrooms at the same time with just the main, will always need a booster arrangement and remember the main may only be 32mm but aslong as the flow rate is enough to satisfy the break tank your ok. Also remember your not meant to be pulling more than 12l min direct from the main from the water boards point of view so sometimes when you fill out the water connection form you have to play with the figures a little.

Thanks for that, i think the custard is going to have to bite the bullet and purchase a booster pump set then....on top of a new incoming main too. Ive just been looking at your pictures link. Thats some nice pipe work there my friend....well done!!!:hurray:
Is it okay if i message you for more advice if i need it? its the first time ive done a dwelling this size. The heating/ hot water i'm okay with, its the cold side i'm not so familiar with.

cheers