Number of downlighters recommended

[shd1970]

Hi everyone,

We have just had an extension finished so its now ready for my sparky to rig up the lighting.
The celings are a little low so we have plumped for downlighters so i dont bang my head on any dangling light fittings.

The sparky deliberated long and hard and has suggested to have them in a random pattern which i am prepared to see how it pans out as we are not overly keen on the "airport runway" effect.

Q : I just wondered if there is there is a general rule of thumb measurement for "number of lights / per m2" ?

I understand that obviously you can have too few or very easily too many.

He is talking about using 8 x 50w on a 4.5 x 4.5 extension on a dimmer.....sound about right ??

Obviously i would prefer him not to start chopping holes in my nice newly plastered ceiling "willy nilly" to "try something out !"

thanks in advance,

Sean

 

[bernardgreen]

we have plumped for downlighters so i dont bang my head on any dangling light fittings.

But you might trip over things in the dark areas between the spot lights.

Seriously think twice about downlighters.

8 x 50 = 400, a lot of power to light up a room that would be well lit by less than 100 watts of non spot light lighting.

 

[Stoday]

You can't have a sensible rule of thumb based on the number or power of lights per square meter because the light level depends so much on the colour and darkness of the floor, wall and ceiling decorations.

The best rule of thumb I've come across is that recessed filament lighting should be five times the power of a bare filament lamp. So if you dangle a bare test lamp in the room and you need 100W to achieve an adequate lighting level, you'll need 500W total of recessed lights — i.e. ten 50W.

Does go to show how inefficient recessed lighting is.

 

[sparkwright]

A lot will depend on obstructions like joists and beams.

The electrician should make a note of where the spots should go and should refer to this when drilling the holes once the plastering has been done.

The lights shouldn't be too 'random', they should be fairly evenly spaced. Some sort of zig zag pattern or even in a full circle would possibly look good.

You should consider wiring them on two separate switches so you don't have to have them all on together.

Wall lights may help the low ceiling issue.

 

[canduit]

You can get recessed ceiling light units that accept lamps like these..

http://www.screwfix.com/p/sylvania-...w&cm_mmc=AffiliateWindow-_-DeepLink-_-Na-_-Na

They spread light better than spots so you'll need less of them. These in conjunction with wall lights with separate dimmers could be worth having a think about.

 

[flameport]

They also accept these lamps:
http://www.tlc-direct.co.uk/Products/LAH8075ES.html or the 50w version http://www.tlc-direct.co.uk/Products/LAH8050ES.html

These are the light fittings:
http://www.toolstation.com/shop/d220/sd3206/p74987

Compared to the 50mm downlights, you will need less than half the quantity.

 

[big-all]

£3 a week and £150 a year to light one room for around 8 hours a day

i light my whole house up like an xmas tree for £19 a year with led and low energy bulbs
needless to say no down lighters

 

[Taylortwocities]

Have you thought about The requirements of Building Regulations for the lighting. As this is anew space BR Part L1B mandates that 75% of the lights must comply with the stringent low energy requirements.

So, look at the requirements first. That will give you a strong direction as to your "choice" of light fittings. Building Control will make you rip it out if you (or your electrician) don't get it right.

 

[ban-all-sheds]

Q : I just wondered if there is there is a general rule of thumb measurement for "number of lights / per m2" ?

Yes.

Zero.




OOI - when you submitted your application for Building Regulations approval, what did you say would be the way you'd comply with Part L?

• 
  

 

[Stoday]

Q : I just wondered if there is there is a general rule of thumb measurement for "number of lights / per m2" ?

Yes.

Zero.

Now that's a pig-headed response.

Recessed lighting does have the merit of low glare. If you want to minimise glare you can do so with appropriate recessed fittings, albeit at the cost of the abysmal luminous efficiency of recessed fittings.

If lighting levels are high, 500 lux or more, glare becomes a limiting factor. In commercial applications, glare is reduced if the ceiling is high. If the ceiling's low, then low glare fittings which direct the light down and not to the side become essential.

 

[EFLImpudence]

We have just had an extension finished ...
...The celings are a little low

.................

 

[Alarm]

Did wonder TBH.
No one think how high they were going to be?

 

[Steve]

7ft? Like most new builds these days.

 

[Alarm]

Bless my 10 footers then

 

[bernardgreen]

Bless my 10 footers then

I like my 6 foot sixers and even lower doors in my cottage. People 400 years ago must have been much shorter or enjoyed head banging.

At least they did not have downlighters.