Wetroom requirements and 12v extractor costs

[masamune]

I have a small WC with a wetroom, sort of a rectangular tray and sliding screen really, on the outside wall. This was formed by partitioning the old kitchen.

The configuration has allowed for the old extractor fan hole to be used and now the builder is using for the WC extraction. But he allowed only for standard fan.

The fan is most likely within zone1(will have to measure), just above the shower. I am not sure what the latest regs require but the electrician mentioned a 12v fan needs to be used. The house has a double rcd CU fitted in 2014. I have looked up some information as I am confused over SELV and IP rated with RCD requirements. The electrician came back with a figure of over £100 for the fan which was not discussed or agreed in advance.

I looked up several units for 12v at half or less than half the above figure. I am trying to understand if any special requirements justify the above figure??

 

[EFLImpudence]

240V fans are allowed in zone 1 (and 2) if suitable for the location - IPX4 and stated as suitable by the manufacturer.

New circuits in a shower room must have an RCD.

The price has nothing to do with it; some are really cheap.

 

[mikeyd]

So, Builder allowed how much for a standard fan?
How much over £100 have you been quoted?

It's most likely not in zone 1. Did you think that, or were you told by the builder or the electrician?

SELV is (very) low Voltage, IP rated usually applies to outside your house. RCD requirements you already have.

 

[Taylortwocities]

...

 

[Taylortwocities]

IP rated usually applies to outside your house

No it doesn’t. It applies to many things. The size of holes in enclosures, for example. as well as the rating of Electrical equipment in bathrooms and showers etc

 

[Iggifer]

National Ventilation/Monsoon make Zone 1 suitable 230v fans. We use them occasionally when there's no other choice because a 12v fan is a right PITA.

They're cheap enough too, last one I had was half the price of the Manrose equivelant.

Quick google says you'd pay £40 for MON-S100T which is the standard 4" timer model

 

[EFLImpudence]

National Ventilation/Monsoon make Zone 1 suitable 230v fans.

Everyone does.

I'm not recommending it, although it might be fine for what it is, just pointing it out. £6.29

http://www.discount-electrical.co.u...-fan-for-remote-switching-100mm---4-inch-240v

 

[Iggifer]

Think in a roundabout way that says not to install in zone 1, but we’re still not entirely sure the fan hole is even in Z1

 

[EFLImpudence]

It's IP24.

Do you mean it saying "must not be accessible to persons using either shower or bath"?

 

[Iggifer]

It's IP24.

Do you mean it saying "must not be accessible to persons using either shower or bath"?

Yea. I would wager that I could reach the majority of zone 1 from inside a bath/shower

 

[EFLImpudence]

Exactly.

Can you reach electric showers?

 

[Iggifer]

Showers are IP44 no?

 

[EFLImpudence]

No, same IPX4.

 

[EFLImpudence]

or IPX5 if subject to jets - same as anything else.

 

[masamune]

So to provide more clarity on the shower, I have attached two photos with guides. The enclosure is located under the stairs, fan hole at the top and the fixed shower arm is to extend 200~300mm off the small right side hole, further below. The bottom line of the fan hole is at 2.25m from the tray give or take.

I presume this falls within zone 1?





The 12v requirement came from the electrician. My understanding now is that if Z1 an IP rated fan could be used as the CU is modern and has an RCD?

Both IP rated and SELV 12V fans come at a fraction of the figure the electrician is asking for his fan...