How many downlights in a room?

[MrGwythers]

Hello I'm an apprentice looking for tips and techniques. I asked this question before but got no response.
When it comes to installing downlights what is your method for how many downlights you require?
Do you do the lumen calculation or are there other quick ways to do it.
Thanks.

 

[pc1966]

There are some on-line light calculators such as this:

Lighting Calculator

This lighting calculator determines how many light bulbs you need to illuminate a particular space.

www.omnicalculator.com

But critical to the overall question is:

• What folk will do with the room
• To some extent if it is decorated light or dark colours
• How even the lighting has to be, and/or if any points in the room need special highlighting (e.g. kitchen work top)
• Folks personal preferences for light intensity (I like bright light so I can read or do detailed work, some friends find it too much and just want low light for not walking in to things / standing on the kids or pets, etc)

Having some control also helps, whether it is dimmable lights or (in large area) switching of banks to allow various levels to be achieved.

 

[MrGwythers]

There are some on-line light calculators such as this:

Lighting Calculator

This lighting calculator determines how many light bulbs you need to illuminate a particular space.

www.omnicalculator.com

But critical to the overall question is:

• What folk will do with the room
• To some extent if it is decorated light or dark colours
• How even the lighting has to be, and/or if any points in the room need special highlighting (e.g. kitchen work top)
• Folks personal preferences for light intensity (I like bright light so I can read or do detailed work, some friends find it too much and just want low light for not walking in to things / standing on the kids or pets, etc)

Having some control also helps, whether it is dimmable lights or (in large area) switching of banks to allow various levels to be achieved.

Cool, thanks for the reply all the jobs I'm on are big sites and have designs/drawings with them all layed out so want to learn for if I ever go at it alone.

 

[Dannyboybl00]

You need to consider celling height, wall colour, any other local lighting (feature lights, wall lights),
As a general rule on ceilings around 2400 ffl I'll go for between 1200 and 1400mm spacing between the downlights with around 400lm lamps.

Integral LED fittings tend to have a lower spread angle than GU10s so this needs to be taken into consideration when spacing or trying to achieve a certain lux level.

 

[DefyG]

the jobs I'm on are big sites and have designs/drawings with them all layed out

Have they been 'designed' or are they just the architects interpretation of a proposed layout?

 

[Dustydazzler]

In the old days of halogen downlights , general room lighting about every 1.5 mtr , and kitchens every 1 mtr

it Wasn’t an exact science but that was how I did it

 

[Mike Johnson]

Lux levels and colour range have a massive impact on the room, as has been said above it accords to what the room is used for, IMO daylight white in a kitchen, but lots of people go for mood lighting in all the rooms, so dimmers come into the equations, there are specialist companies that do this type of thing and earn lots doing it.

I was involved with a high profile celebrity (the one with the silly laugh) and mood lighting was a priority during the design and build, I met him a couple of years later and asked if he still used the very expensive dimmers, he said no they just found the level they liked and left it there.

 

[Zerax]

I know it's a personal opinion... but even 1 downlight is 1 downlight too many ! I always try to light the walls/ceilings if I can... although for me, lighting design is a difficult and complex thing.

 

[Mike Johnson]

The norm now days in high end properties is dropped ceiling around the perimeter of the room and strip lighting recessed behind the drop, with downlighter in the high part separately switched, all with colour changing controlled from a remote or an iPhone. ?

 

[FatAlan]

My designs tend to be based on where the ceiling joists are ?

 

[Strima]

I know it's a personal opinion... but even 1 downlight is 1 downlight too many ! I always try to light the walls/ceilings if I can... although for me, lighting design is a difficult and complex thing.

All well and good but not ideal when you can't see to chop the carrots up.

 

[Zerax]

All well and good but not ideal when you can't see to chop the carrots up.

Well... eating more carrots would help with that.

But seriously... to me that's 'task lighting'... so yeah directed light is needed, but from the ceiling ? I'm amazed at the number of brand new kitchen installs that I see without under cabinet lights !

 

[Strima]

I'm amazed at the number of brand new kitchen installs that I see without under cabinet lights !

Like the ones I put in for my wife but she's now covered all the worktops in 'stuff' so pointless having them... ???

 

[Mike Johnson]

Ceiling lights are fine if you live in a very old building where you can reach the ceiling just standing up, makes decorating easy. ?

 

[MrGwythers]

Have they been 'designed' or are they just the architects interpretation of a proposed layout?

All designed with spacing measurements all ready given the engineers use dialux software which can work it all out for you. It's good for the big jobs but just wanted to know a quicker way for small domestic jobs instead of time consuming software design.

 

[MrGwythers]

I'm still learning this lighting design process there is alot of stuff to think about, from most videos I've watched from credible lighting designers and from what's been mentioned in the thread, downlights are going out of fashion and strip lighting around the perimeter in the coving is the new preferred look.

 

[moose]

Its been a while but, here is my ten pence worth. Hope it helps.

Its not a new thing its just re designed fitting upgrade. I have worked on old Erm is it Coffers a form of cavity within the ceiling lit with don't laugh but a good old fluro 6ft all lined up to form the continues line of bright light.

LED all lined up look the same. New tech and needs sorting out.

The ceiling thing for your knowledge just look up and say will this look good with 4/ 6 or 8 lights you will always find you can make a fit and usually looks great to see when finished.

Measure the ceiling and Divide by 4 fittings +1wall (5) Then this will space out your fittings.

So 4000mm divide by 5 = 800mm between each fitting. and soo on.

Remember too many and it will look ridiculous. Once you do one you learn by your mistakes.
I myself feel that LED at the moment are far to bright and need to be reduced. So make sure you know what you are fitting. power wise. they all look different and are powered very different saying the same power outings. example 3.5w 4w 5w and all do the same light. Some are more intense than others.

 

[Mike Johnson]

All LED's normally have a lumen output denoted on them, the important thing is if you need Daylight or Warm white output, lumen's go down with the Daylight White that looks like an old tungsten light, better for lounge, but Daylight White for work area's i.e. Kitchens.

 

[nicebutdim]

All LED's normally have a lumen output denoted on them, the important thing is if you need Daylight or Warm white output, lumen's go down with the Daylight White that looks like an old tungsten light, better for lounge, but Daylight White for work area's i.e. Kitchens.

I don't like anything other than warm white (3000K) for general lighting in kitchens, especially if they incorporate a dining area, but prefer 4000K for under cabinet lights.

 

[Mike Johnson]

I did say working area's.

 

[LastManOnline]

My designs tend to be based on where the ceiling joists are ?

Spot on. First and most important question to be asked when planning to install downlighters in my book. There are lots of variables that provide flexibility when installing downlighters but the joists really are bottom line. Then design the layout so you totally eradicate the need for any repairs to ceiling (with the exception of the existing ceiling rose which might require a MF JB and a touch up. Though many are happy to let the rose minus the pendent)

 

[telectrix]

1 yard or thereabouts between each light. no light closer than 2 ft. from a wall. some sort of attempt to get them in straight line/s. works for me.

 

[FatAlan]

If planning a kitchen make sure you take into account units that go right up to the ceiling or there abouts ?

 

[brianmoooore]

My designs tend to be based on where the ceiling joists are ?

If planning a kitchen make sure you take into account units that go right up to the ceiling or there abouts ?

Both very important points. I've seen downlights carved into the side of joists, and downlights illuminating the dust on top of tall cupboards.

 

[R-fur]

Last time I did a rewire it was still a pendant in the middle of the ceiling. However a friend asked me to wire a new build house he was building for his retirement so I had some lessons to learn.
I agree with the comments above about wall colour height of ceiling etc but for general lighting with all white walls and modern ceiling height, I worked on each fitting lighting a 2x2 meter area of floor and found that this worked well, but as above, position of the joists was important. Also I avoided putting fittings above the head of where a bed was going. You don't want to be lying in bed with a light in you face. There were other lights such as wall lights in the living room and cabinet lights in the kitchen, but I treated them as extras. I also used good quality fire and acoustic fittings with separate lamps. I have had cases where one fitting fails and you cant get an exact replacement so all the fitting in the room have to be changed. Another reason for wanting replaceable lamps was in case my 'design' wasn't bright enough, I could just fit higher powered lamps.
Two years on my friend is still happy with the lighting.

 

[Mike Johnson]

Both very important points. I've seen downlights carved into the side of joists, and downlights illuminating the dust on top of tall cupboards.

Reminds me of a song "I'v seen sunshine I'v seen rain"

But the above only happens when the installation is not designed its just put up where someone thinks it ought to go, no excuse except maybe for the first hole that may hit a solid strut that was used instead of herringbone, there are not many ceilings that with a high powered narrow beam torch you can't identify the line of the board or spotting of the nails, there are some, but not many.

 

[nicebutdim]

Reminds me of a song "I'v seen sunshine I'v seen rain"

But the above only happens when the installation is not designed its just put up where someone thinks it ought to go, no excuse except maybe for the first hole that may hit a solid strut that was used instead of herringbone, there are not many ceilings that with a high powered narrow beam torch you can't identify the line of the board or spotting of the nails, there are some, but not many.

Neodymium magnets will find just about every joist.

 

[Mike Johnson]

I did not know that wooden joist where magnetic. ?

 

[DefyG]

spotting of the nails

You've been outta the game too long, screws are used by boarders today.

I use a metal/stud detector, doesn't take too long to identify a line of screws and hence a joist/noggin!

 

[Mike Johnson]

You've been outta the game too long, screws are used by boarders today.

Your right there, but I still have a bag of clout nails in the barn. ?

 

[DefyG]

Your right there, but I still have a bag of clout nails in the barn. ?

Worth holding onto, you never know!!!!.........

 

[Mike Johnson]

Do you think it's worth holding onto the cwt of cut nails as well. ?

 

[DefyG]

Do you think it's worth holding onto the cwt of cut nails as well. ?

cwt? probably not but might be worth a few £'s or Euro's at a scrap yard!

 

[Zerax]

cwt?

short for 'hundred weight'... which is about 50kg.

 

[DefyG]

short for 'hundred weight'... which is about 50kg.

Hi Zerax, I know what it stands for, just querying the quantity Mike has in his shed.

 

[DPG]

As above, use neodymiium magnets. They will find the screws, and hence where your joists are. You can even leave them stuck to the screw heads while you're working stuff out.

Have a google of the studbuddy tool. Careful how you search though

 

[loz2754]

As above, use neodymiium magnets. They will find the screws, and hence where your joists are. You can even leave them stuck to the screw heads while you're working stuff out.

Have a google of the studbuddy tool. Careful how you search though

+1 for the studbuddy

 

[telectrix]

short for 'hundred weight'... which is about 50kg.

50.8023 to be exact. ?

 

[Mike Johnson]

50.8023 to be exact. ?

My Gast is Flabbered, Tel used metric. ? The sky is falling, RUN.

 

[telectrix]

told you i was bilingual. but i don'tever use metric. just learnt to live with it to keep up with the young sprogs.

 

[Mike Johnson]

What you do in the privacy of your home is your business. ?

 

[pc1966]

Have a google of the studbuddy tool. Careful how you search though

Yes, I remember a fellow student who eventually did his PhD in degradation of rubber insulation as work funded by Railtrack who has issues with signalling cables failing (in addition to scrots stealing them).

You would not believe what he got from his naive search!