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:

 

[sean_ork]

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?

Post a link please, I'll find its flow rate - there's no point getting excited over it if its flow rate is 2 dribbles a fortnight.

 

[sean_ork]

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!

Maybe some folks want a meal that doesn't just consist of toast and beans

 

[davesparks]

Post a link please, I'll find its flow rate - there's no point getting excited over it if its flow rate is 2 dribbles a fortnight.

Quooker is the best known one, but there are other brands out there.

 

[davesparks]

Maybe some folks want a meal that doesn't just consist of toast and beans

??? That's just daft, you can cook a while roast dinner with just a few pots and pans if you know what you are doing.

 

[sean_ork]

Quooker is the best known one, but there are other brands out there.

I suspected you'd say that - you do know there's a small tank hidden away feeding it ? The only advantage of these £1200 taps over the £145 versions is boiling water and a very fancy tap.

3kW just isnt enough to heat water instantaneously for the flow rate required

http://www.quooker.co.uk/enuk

 

[sean_ork]

??? That's just daft, you can cook a while roast dinner with just a few pots and pans if you know what you are doing.

OK let's assume you can do what no one I've ever known has been able to do ........

So what about the 2,4 or 6 folks who sit down to scoff that roast - will they be using any plates, knives, forks, spoons, then there's pudding, that's maybe 6 more bowls and spoons, then there's a cuppa afterwards, then the cheeses and more drinkies ... that's a good few sinks of washing up, average domestic sink capacity of say 25 litres ?

rough calculation - 10 litres of water, say its incoming at 10 degrees, 90 degrees rise required - 3kW element - that's nearer to 20 minutes to raise that volume to near boiling

 

[Leesparkykent]

Why not just have a unvented cylinder with an immersion or even twin immersion? and you could run the shower off it. Small solar thermal setup on the roof to keep it topped up throughout the day with something like the solar iboost so when the pv is producing more than what's being used it also heats the hot water.

 

[davesparks]

OK let's assume you can do what no one I've ever known has been able to do ........

So what about the 2,4 or 6 folks who sit down to scoff that roast - will they be using any plates, knives, forks, spoons, then there's pudding, that's maybe 6 more bowls and spoons, then there's a cuppa afterwards, then the cheeses and more drinkies ... that's a good few sinks of washing up, average domestic sink capacity of say 25 litres ?

rough calculation - 10 litres of water, say its incoming at 10 degrees, 90 degrees rise required - 3kW element - that's nearer to 20 minutes to raise that volume to near boiling

You do your washing up in boiling water?

 

[sean_ork]

You do your washing up in boiling water?

No, but that's an argument against having a tap that produces boiling water

 

[sean_ork]

Why not just have a unvented cylinder with an immersion or even twin immersion? and you could run the shower off it. Small solar thermal setup on the roof to keep it topped up throughout the day with something like the solar iboost so when the pv is producing more than what's being used it also heats the hot water.

Great, until the sun doesn't shine - and then you've got heat loss from the cylinder and the dead legs - which most folks don't seem to mind wasting their money on living in their conventional energy inefficient home, but that's not what the OP wants to build.

 

[davesparks]

Great, until the sun doesn't shine - and then you've got heat loss from the cylinder and the dead legs - which most folks don't seem to mind wasting their money on living in their conventional energy inefficient home, but that's not what the OP wants to build.

Solar hot water setups are surprisingly good even with minimal available sunlight.
With some careful thought as to the layout you could get the dead legs to be fairly short. And a thermal store rather than a conventional cylinder would presumably help too? (they must have come up with something better than the gledhill heaps of junk by now)

I don't think it's so much a case of not minding about living in inefficient homes, but more a case of not knowing and not being able to do much about it if they did.

 

[Leesparkykent]

Great, until the sun doesn't shine - and then you've got heat loss from the cylinder and the dead legs - which most folks don't seem to mind wasting their money on living in their conventional energy inefficient home, but that's not what the OP wants to build.

A well insulated cylinder/thermal store in a well insulated house the the loss of heat is going to be minimal surely? Same applies to the dead legs...pre insulated pipe and legs as short as possible. Solar thermal works well even on the not very best of days, you would be surprised.

 

[janner43]

OK - someone said I had lost interest in the thread. Nope. I'm just not willing to debate the often ill informed comments that have been posted along with the insightful ones.

Only Sean and spinlondon apparently have any real experience of this type of build. Other than the eminently sensible electrical design advice that has been given which I have already said is making me seriously consider changing the rating of the water heaters, 80% of the posts are just argumentative and "you don't want to do it like that". I said I didn't want to debate the design scenario, but there appears to be a lot of interest (or maybe not).

I understand the reasons why folks don't know or haven't considered alternative build or design scenarios. I also understand the uselessness of many of the alternatives that are out there which are only really useful in two cases.
1) Where the environment is harsh and requires it
2) Where the technologies are being fitted as part of a refurb rather than a new build.

Where we live the average winter temperature doesn't fall below 3.7° - Plymouth, England Climate Plymouth, England Temperatures Plymouth, England Weather Averages
As a result, high levels of insulation and air tightness coupled with an efficient MVHR should mean no heating is required over that generated naturally within the home.

These things are calculated properly and scientifically and do not require opinion. If top up heating does prove a requirement, I think you'd agree that adding a 1.5kw panel heater somewhere shouldn't prove too challenging!!!

As it is my home, my opinion on the quantity and frequency of hot water that will be required is such that showering and hand washing are all that should take place. We wash our clothes in a washing machine. We wash our dishes in a dishwasher. What you might do is a matter for you.

We are trying to build a 21st century home - not an 19th century one. We are using state of the art knowledge and techniques. Only one other home has been built in the UK to date using the build method we are using. That was the proof of concept in Scotland. Ours will be the first commercially built home after that.

I have also effectively been called a liar - the first time it was reasonable and put in a polite way and I understood and answered it. After that it is just offensive.

In short, while you guys unquestionably know more about electrical science than I. I am not going to take lessons in the overall design concept or in day to day living paradigms from you, thanks very much.

Finally, again my genuine appreciation to the posters who have helped with their constructive suggestions and observations.

 

[Octopus]

OK - someone said I had lost interest in the thread. Nope. I'm just not willing to debate the often ill informed comments that have been posted along with the insightful ones.

Only Sean and spinlondon apparently have any real experience of this type of build. Other than the eminently sensible electrical design advice that has been given which I have already said is making me seriously consider changing the rating of the water heaters, 80% of the posts are just argumentative and "you don't want to do it like that". I said I didn't want to debate the design scenario, but there appears to be a lot of interest (or maybe not).

I understand the reasons why folks don't know or haven't considered alternative build or design scenarios. I also understand the uselessness of many of the alternatives that are out there which are only really useful in two cases.
1) Where the environment is harsh and requires it
2) Where the technologies are being fitted as part of a refurb rather than a new build.

Where we live the average winter temperature doesn't fall below 3.7° - Plymouth, England Climate Plymouth, England Temperatures Plymouth, England Weather Averages
As a result, high levels of insulation and air tightness coupled with an efficient MVHR should mean no heating is required over that generated naturally within the home.

These things are calculated properly and scientifically and do not require opinion. If top up heating does prove a requirement, I think you'd agree that adding a 1.5kw panel heater somewhere shouldn't prove too challenging!!!

As it is my home, my opinion on the quantity and frequency of hot water that will be required is such that showering and hand washing are all that should take place. We wash our clothes in a washing machine. We wash our dishes in a dishwasher. What you might do is a matter for you.

We are trying to build a 21st century home - not an 19th century one. We are using state of the art knowledge and techniques. Only one other home has been built in the UK to date using the build method we are using. That was the proof of concept in Scotland. Ours will be the first commercially built home after that.

I have also effectively been called a liar - the first time it was reasonable and put in a polite way and I understood and answered it. After that it is just offensive.

In short, while you guys unquestionably know more about electrical science than I. I am not going to take lessons in the overall design concept or in day to day living paradigms from you, thanks very much.

Finally, again my genuine appreciation to the posters who have helped with their constructive suggestions and observations.

Probably because you did little of nothing to persuade the masses that you actually have a sparky involved.......

 

[janner43]

Probably because you did little of nothing to persuade the masses that you actually have a sparky involved.......

Look, I do understand why you and others may be dubious - but then again I have stated that there is an electrician and given you all sufficient background to perhaps trust my word on the matter. I don't have the time or inclination to attempt to convince people who are not going to be convinced in any case.

Neither do I have the time or inclination to, as someone put it "argue with an idiot as they will drag you down to their level and beat you with experience".

Neither am I going to debate further than this reply my personal integrity. The facts I have posted in the OP are true, the whole truth and nothing but the truth.

 

[Octopus]

Back to a sensible question - you made a statement about the property being "sealed" or similar - how do you get rid of unwanted moisture?

 

[telectrix]

Back to a sensible question - you made a statement about the property being "sealed" or similar - how do you get rid of unwanted moisture?

and what happens when all the air has been used up, and he's breathing in CO2?

 

[sean_ork]

and what happens when all the air has been used up, and he's breathing in CO2?

Clearly you don't know what MHRV is, or how it works.

 

[sean_ork]

Back to a sensible question - you made a statement about the property being "sealed" or similar - how do you get rid of unwanted moisture?

It's mechanically recovered by the whole house ventilation system.

 

[DPG]

I think people need to look towards these new ideas rather than ridiculing them and sticking to how things have always been done. If we didn't progress like this then we'd still be living in houses with no cavities and no loft insulation. And we'd still have houses full of 60W and 10W lamps. Daz