Self Build Advice Please - consumer units, sockets & switches...

[Leesparkykent]

Agree, gonna have a look in abit as I'm nosy ,but do you remember where you found this info Reg Ect.

Its common sense really but 433 covers protection against overload current. 433.1, 433.1.1 and so on.

 

[davesparks]

Agree, gonna have a look in abit as I'm nosy ,but do you remember where you found this info Reg Ect.

Common sense and experience is where I got it from.
Common sense: don't design an installation which relies on a fuse running at more than it's rated current.
Experience: fuses which run at their rating/just over there rating get weak and blow for no apparent reasons.
Also from experience a 100A cutout being regularly loaded to 120A will get very very hot and smell rather nasty (overload revealed from a load study carried out after the cutout was replaced)

 

[plugsandsparks]

100A fuse ? I would get that in writing before making such a design assumption. 63A more likely me thinks

 

[sean_ork]

OK, thanks to everyone for your advice.

The thread can be closed now as far as I'm concerned.

Don't be disheartened, many trades in this Country don't like change, most builders still think block/brick build is the only way - ask them about air tightness testing and you'll get the same belligerent responses as you've seen here.

We've done very similar to what you are aiming at, but before PH became trendy - luckily we have an almost endless supply of energy blowing past so our energy source was easy to pick. Your calcs probably show you won't need any significant energy input for space heating, as did ours - but we specified all flooring to be highly insulated 8'' conc with both electric loose laid heating, and wet UFH - and a fairly large TS - with plenty of coils, stat probes and three immersions - lots of thermal mass.

Your instantaneous heater proposal is sound - heat at the point of use, and only heat what you need is a concept clearly lost so far in this thread.

But do ensure you pander to those who might live in the house after you by ensuring gas is at least piped to the likely areas of use, you don't need to have a supply, just a feed from your utility box.

We spent time in Norway and Sweden before signing off, they know how to build properly over there - hopefully trades in this Country might catch them up eventually.

You'll likely be aware already, the Green Building Forum will be much more receptive of your "wild" ideas - also talk to Viking House, they have some innovative MHVR solutions - also their general building and detailing drawings are a goldmine of ideas.

Good luck.

 

[joehat]

Its common sense really but 433 covers protection against overload current. 433.1, 433.1.1 and so on.

I would have looked in that section yes but would never design above 100a do didn't know it has that in the regs book as its not ours to touch,, soso!!

 

[Lagentium]

I don't think this thread is all it appears to be to be honest!!! Why start a thread then say it can be locked? Once you've started the ball rolling it will roll and roll!

 

[Dave OCD]

I know the OP has lost interest in this thread now but using 12kW water heaters to provide hot water to a kitchen sink and shower room wash basin respectively seems insane to me, a couple of small unvented water heaters which hold a small amount of water with thermostatic control and consuming under 3kW each such as the Ariston type would surely be far more sensible ?

 

[Midwest]

Don't be disheartened, many trades in this Country don't like change, most builders still think block/brick build is the only way - ask them about air tightness testing and you'll get the same belligerent responses as you've seen here.


Your instantaneous heater proposal is sound - heat at the point of use, and only heat what you need is a concept clearly lost so far in this thread.

But do ensure you pander to those who might live in the house after you by ensuring gas is at least piped to the likely areas of use, you don't need to have a supply, just a feed from your utility box.

I could not agree more on a soundly built house full of insulation, and save on my bills, don't care what it's made of, straw & mud wouldn't bother me. Not sure whay the OP wants a 12kw water to wash up the dishes for? The Redring one I looked at by the way, said unsuitable for kitchen sinks? Good advice re the gas supply though, future proofing. Although, if you believe the headlines, no use after 2030!

 

[sean_ork]

a couple of small unvented water heaters which hold a small amount of water with thermostatic control and consuming under 3kW each such as the Ariston type would surely be far more sensible ?

Do you keep a kettle of boiling water ready at all times for those few times during the day when you want a brew ?

 

[Dave OCD]

Do you keep a kettle of boiling water ready at all times for those few times during the day when you want a brew ?

No but I don't start up a small nuclear reactor to boil a couple of pints of water either.
And unlike a kettle the type of heater I described is very well insulated so once the thermostat temp is reached the water will stay hot for a long time without further current being drawn.

 

[davesparks]

Do you keep a kettle of boiling water ready at all times for those few times during the day when you want a brew ?

No, but a 12kW water heater to fill the kitchen sink is also a little ridiculous when far lower powered instantaneous water heaters exist which will serve the same purpose.

You can now get a tap with a built in 3kW instantaneous heater to provide boiling water on tap, so why would you need a 12kW heater to get water at a around 60degrees?

 

[sean_ork]

No but I don't start up a small nuclear reactor to boil a couple of pints of water either.
And unlike a kettle the type of heater I described is very well insulated so once the thermostat temp is reached the water will stay hot for a long time without further current being drawn.

10l maximum ? then its 10? minutes wait till for more hot water - that's the reason folks want high current instantaneous heating

 

[Dave OCD]

10l maximum ? then its 10? minutes wait till for more hot water - that's the reason folks want high current instantaneous heating

Isn't 10 litres enough to wash your hands, have a shave or wash a few dishes then ?

 

[sean_ork]

You can now get a tap with a built in 3kW instantaneous heater to provide boiling water on tap, so why would you need a 12kW heater to get water at a around 60degrees?

What's the flow rate ?

How many litres does the average kitchen sink hold ?

 

[sean_ork]

Isn't 10 litres enough to wash your hands, have a shave or wash a few dishes then ?

Probably, but doing a few sinks worth of dishes could get tedious

 

[Dave OCD]

Probably, but doing a few sinks worth of dishes could get tedious

Well you shouldn't be lazy and let them build up like that.

 

[davesparks]

What's the flow rate ?

How many litres does the average kitchen sink hold ?

How on earth should I know? You'd need the flow rate at the point of connection to find out what it will be out of the tap!
From experience the boiling water is not noticeably slower than the regular hot from a tap.

Again how the hell should I know the average volume of a kitchen sink?

I'm only asking why such a large amount of power is necessary to achieve the same result as can be achieve with much less power?

 

[davesparks]

Probably, but doing a few sinks worth of dishes could get tedious

I thought the whole point of this was energy efficiency?
Using a few sinks worth of dishes to cook a meal is not very energy efficient when meals can be cooked with far fewer dishes!

 

[Deleted member 26818]

I prefer instantaneous heating over tanks.
RedRing do one that is suitable for 2/3 sinks, or one sink and shower, cost me £145 when I purchased it.

 

[Midwest]

Probably, but doing a few sinks worth of dishes could get tedious

Get a dishwasher :smiley2: