Lighting

[Daz2410]

Hi,
Is there a way to work out how many down lights will be required to light a room?

Also we have exposed timber beams, I’m guessing the only way to wire down lights is to take the floor up upstairs?

Cheers,
Darren

[Scotty001]

If you Google room lighting calculator you will find lots of free calculators to help you with this. (including spacing between lights) but you will need to know the beam angle of the lights and type of lights you want to use.

It would certainly be easier to lift the floor boards in the room above, it can be done without doing so but much more complicated and making good of the ceiling required.

[Daz2410]

Thank you, I did try one of the free calculators but it wasn’t very detailed- it certainly didn’t ask for light angles so I’ll have another look

Thanks for your advice

[ericmark]

I have got it wrong in the past, lighting not easy, I replaced fluorescent tubes for low bay lights with ceiling height at around 5 meters and worked very well, so did same with another building ceiling height at around 2.2 meter and really a failure.

The 2 inch (or 16 x 1/8 inch as it is called) lamp does not have a good spread, I fitted two as bed side lamps to read with, aimed down at bed room very dim, turn them and aim at while ceiling did not do bad job of lighting room, the light being reflected off ceiling, so in a kitchen with loads of white surfaces to reflect the light from, they can work far better than a living room with dark carpet.

So if we use 16 x 2W the light is far better than 8 and 5W even when the wattage and lumen is increased. So this room

98361719_10158572386853420_1054327038518755328_o.jpg (95.13 KiB) Viewed 2514 times

with a high ceiling worked well with down lights MR16 GU10 (MR16 is size and GU10 is electrical connection) I think he used around 16 it did have a 65 watt fluorescent which was changed to a 22 watt LED tube and I know seems as bright now but wattage is more like 58 watt which is same as modern fluorescent tube 5 foot so may look better but actually uses more power.

I would say rule of thumb work on using no larger than 3.5 watt, so 300 lumen per lamp, over that it needs to reflect off something to use the light, so if your calculator says you need 3000 lumen, then you need 10 lamps. The 50 mm down light is more decoration than lighting, use the 2 foot square down lights for efficient lighting, but efficient lighting = office type lighting, firms are not daft, they use the most efficient so if you use most efficient it will look like an office.

[Daz2410]

Thank you very much for your help, we have low ceilings (approximately 7’) and exposed beams.

[Someone-Else]

Most people just "guess" how many lights, or make nice pattern, no not joking, seen it done often.
As said it can be calculated, but you have to know how bright you want it and at how high you want it that bright, and reflective surfaces have to be considered, as do cupboard tops. (Say you have a room 3 x 4 and you figure it will have 12 lights, but you forgot, you have cupboards down one side, so you loose 0.5 off of the ceiling area, so your 12 lights now have to fit in a smaller area)

One thing I would suggest.

Example only:

You have 3 rows of 3 lights

These lights are either all on or all off, so it's bright or dark.

If you wired the two outer rows to one switch, and the middle row to another switch, you now have 3 light levels from 2 switches.

Switch one. 3 centre lights
Switch two. 6 outer lights

So you can have 3 lights on, or 6 lights on or if you switch both you can have 9 lights on, and since you won't be staring at the ceiling, it gives a simple way of giving different light levels with no dimmers.

[Daz2410]

Thank you for your advice, I like the idea of having them on 2 switches

[Chippo1]

The rule of thumb works for me !

[Nos]

When I wanted new lights for our house here I used a Uk company to supply them, I wanted a LED Hybrid which they did, they also sent me a plan for each room with a Lux scale for each light, been in a year, apart from the flicker all good.

[Daz2410]

Thanks NOS, what’s the company name please?

[Nos]

If Iam allowed to its "Downlighters.co. Uk." Nos

[ericmark]

I lived in an old listed building with black beams, and it was rather hard to light due to low ceilings, you need a reasonable area for the light, spot lights are really not suitable. There are down lighters like this one Screwfix (240HT) that use a larger area and are not as deep, or this surface lamp Screwfix (2128T) which because it is not flush with ceiling will likely give a better spread of light.

It is a compromise looks to functionally, the further the light is from the ceiling the better the spread, so I would say surface mount would be better.

[Daz2410]

Thanks ericmark, I have cut the holes and purchased the lights now

I’m looking for advice on how to cut inspection holes in the plasterboard between the beams, I want to see what’s above the plasterboard. Ideally I want to cut a panel out have a look then put the piece I cut out back and make good