How many lumens for a bathroom?

[Kitsune]

Hi
Looking for a bit of advice over number of down lights needed for a bathroom which is about 2.5m by 2.3m. I've found some IP65 LED down lights that I like which are 4.5w and 275Lm. I've looked at a couple of online calculators for how many lumens I'll need for the bathroom which range from about 3000 to 5000 which would mean over ten lights so I figured I must be working something out wrong.

I was thinking of buying either four or six, would four be enough? The bulbs can be changed to a higher wattage but they come with 4.5w ones, they would be cool white.

Thanks for your help

 

[ericmark]

I have bought some LED bulbs and been surprised at the results. Office 250 lumen, my living room 1240 lumen, mothers living room 806 lumen and kitchen extension 2400 lumen. The 2400 lumen in the kitchen extension replaces a 5100 lumen fluorescent tube yet it does not seem any dimmer, the 1240 lumen in living room 10 bulbs replaces 3800 lumen compact fluorescent lamps again looks no dimmer. The office bulb is dimmer than original but also use a 900 lumen folded fluorescent tube (G23) so ample.

What is important is the colour of any surface the light is reflected from. Living room 10 bulbs face up against a white ceiling. Aim a bulb at a dark floor and it will not reflect any light so aim spot lights to bounce light off a white wall and the result will be very different to aimed at grey or black floor.

In my bed room I have two x 2W LED spots on ceiling plus an 11W CFL and on the wall separate switched I have a 2W and a 5W reading lamp above the bed. The latter two normally aimed at bed and although good enough to see with the light is hardly good enough without the ceiling lamps. However as an experiment I pivoted the two bedside lamps to shine onto the ceiling. It seemed I had twice as much light in the room as to when shining on the bed.

The angle of spot lights can be confusing the 2W state 30° and the light is even spread, but the Osram 5W states 25-35° and it is centre weighted so more light in the 25° area than between 25° and 35° area. So on pods aimed at white walls then likely need about 750 lumen for a bathroom. But aimed at the floor with dark tiles and even 1500 lumen may look dark.

The LED G13 2300 lumen tube I have in kitchen extension spreads the light out 5 foot long and 1" wide where the B22d 806 lumen is concentrated into a 3" round dome so the spread is no where near as good.

If lighting a 8 x 6 foot room with light coloured walls and ceiling then I would say 500 to 1000 lumen according to how bright you want the room. To light a bathroom with 250 lumen with a second 250 lumen lamp above the shaving mirror would be ample for most people. Should be able to emulate Jasper Carrot and aim to hit bathroom mirror at 3 foot when inspecting the zitts! But if no light above mirror then may need extra over all lighting to inspect any spots!

Spot lights are a problem if not directed at a white surface. Mothers Wetroom is about 8 foot by 7 foot and three x 120 lumen GU10 (2W) spots is ample they replaced 3 x 50W halogen which were really far too bright. My mother clearly does not shave so there is no real need for super bright lighting.

 

[flameport]

275 lumen from a 4.5W LED lamp is dismal.

For 2.5m by 2.3m, 4 of these: http://www.toolstation.com/shop/sd2681/p59250

 

[ericmark]

275 lumen from a 4.5W LED lamp is dismal.

For 2.5m by 2.3m, 4 of these: http://www.toolstation.com/shop/sd2681/p59250

I did look at lumen per watt. My lamps range from 60 to 100 lumen per watt generally the larger the lamp the better lumen per watt. The two GU10 I have are 60 lumen per watt for 2W version and 70 lumen per watt 5W version. His are 61 lumen per watt which is poor but still around the expected level for that size of bulb.

Point is also the price my 2W bulbs were 3 for £10 one you link to is £6 also warm white are not as good as white lumen per watt. At 3000k I would not call it warm I think 2700k is warm.

 

[Kitsune]

Thanks that's a really comprehensive reply and really helps I'll stick to four spots as they will have a combined lumen of 1100 and although the wall tiles will be dark grey the painted parts of the wall will be light and so will the floor. We are also having an illuminated mirror so that helps too.

Just need to think of the positioning now, if set out in a rough square would you have them equal distance from the wall and each other or place them according to the layout but have them marry up along the same lines?

Thanks

 

[flameport]

For even coverage, measure the width of the room, divide by 4, that is how far from the wall each of the 2 lights is. The space between the lights will be double that distance.
Same for the other direction.

 

[Kitsune]

brilliant thank you