Storage heaters & Maximum demand

[gselectrical]

Evening all.

Pricing a job at the moment. Complete re wire. Property has a single 100A supply (prob 80A fuse)

There are 8 storage heaters on the drawings.

How many would you normally fit in a property with a single supply taking into account maximum demand? (2.55kw average)

Cheers

 

[gselectrical]

Evening all.

Pricing a job at the moment. Complete re wire. Property has a single 100A supply (prob 80A fuse)

There are 8 storage heaters on the drawings.

How many would you normally fit in a property with a single supply taking into account maximum demand? (2.55kw average)

Cheers

 

[ProDave]

Well simple maths says 8 3KW storage heaters is 24KW input or 100A (that's input power not storage KWH)

But I doubt they will all be 3Kw. Say two 3KW and 6 2KW gives 18KW or 75A

But whichever way you look at it, at night, as soon as the off peak kicks in, and all heaters are on, you have got just about all your available power in use. That's before you allow for a 3KW immersion heater (almost certain you will have that) and before someone boils a kettle, turns on the washing machine etc.

So I think you need to look at a larger supply, quite possibly 3 phase?

I was once asked to quote for two 18KVA electric boilers running in tandem. The cost of getting a 3 phase feed made the customer decide to get an oil fired boiler instead.

 

[Larnacaman]

If this is a re-wire, are you saying that they have these storage heaters now, or planning on having them installed after the rewire??

If they don't have a gas supply in the property, then they would be far better off going for an oil fired boiler system. Frankly i wouldn't give a thank you for any electrical central heating system, totally uncontrollable compared with a rad system installation....., and cost an absolute fortune to run, on or off cheap rate systems.

 

[steptoe]

Ive done council houses with 8 S H and imm htr and NO issues,

you will prob have a couple of 1.8s or similar, then 2,5s after that,

I know it sounds a lot, but a 60A 1361 takes a lot of hammering.

 

[cadspark]

A holiday cottage close to me with 7 storage heaters and immersion caught fire a few years back. It wasn't a big fire but the fault was put down to overloading. The install had been done by Manweb originally when they had a contracting business. I don't know all the ins and outs but the cutout was upgraded and some of the elements were removed from the storage heaters.

 

[gselectrical]

Well simple maths says 8 3KW storage heaters is 24KW input or 100A (that's input power not storage KWH)But I doubt they will all be 3Kw. Say two 3KW and 6 2KW gives 18KW or 75A

But whichever way you look at it, at night, as soon as the off peak kicks in, and all heaters are on, you have got just about all your available power in use. That's before you allow for a 3KW immersion heater (almost certain you will have that) and before someone boils a kettle, turns on the washing machine etc.

So I think you need to look at a larger supply, quite possibly 3 phase?

I was once asked to quote for two 18KVA electric boilers running in tandem. The cost of getting a 3 phase feed made the customer decide to get an oil fired boiler instead.

Appreciate the fact that it's simple maths. Was just interested in finding out if anybody else had similar experiences. If I where to arrange for another supply to be installed, would it not be best to install another 100A rather than 3 phase???

There where only 3 storage heaters in the property before.

Property consists of bathroom, 3 bedrooms, landing, kitchen, Lining rm and Dining rm. They are an elderly couple, so I don't see them having all the heaters on at once overnight.

They are concidering installing those electric rads. Rointe is it who make 'em?

I know they consume a lot less power but the problem is they would be on during the day then.....along with the kettle, toaster, dishwasher and Imm heater!

Thanks for the reply's

GS

 

[tobo]

I used to install storage heaters on the warm front scheme and have seen that many heaters a few times. if they only have 3 at the min you could suggest having panel heaters in the bedrooms and maybe a down flow heater in the bathroom. take into account the size of the room. a 1.8 or 2.55 for a bedroom. the higher the input the higher the running cost, so we used to advise having the main sitting rooms on 6 and all the others on 3-4. the heaters usually come on between 12 -7am so unless there staying up to do the washing and stuff on the cheap rate you should be OK.

 

[Couleddie]

I recently did a storage heater install at a shop with a flat above. Shop already had 3 x 4 element heaters (although not all elements were connected). Shop and flat were running off a 45A supply branched off the 3 phase supply next door. No gas supply in property.

YEDL visited and were surprised at the installation being connected the way it was and recommended a new 3 phase supply. Customer was happy to pay for this (

 

[Tooold]

I have 2 x 3kw, 1 x 1kw, 4 x 2.5kw, IH not on much tbh, do the washing and dishwashing overnight all on a 100A and have checked cutout etc never warm or anything, it is fairly new tho', did plan to do a clamp test but never got around to it. It isnt the warmest of houses and last year we had it on full blast and still cold spots. I would never choose N/S but would use electric heating with the modern heaters and probably over gas.