Recessed Downlights/Spotlights Spacing Advice

[MandipS]

Hi All,

I am a newbie to all of this so pleae bear with me. I need some advice on spacing of spotlights in all of the rooms in my renovated house.

I am going for 12v MR16 downlights in every room of the house, Osram 2200 Lumens, 36 degree angle bulbs in a variety of normal/fire rated/ip rated Aurora downlights depending upon the room of course.

With respect, please do not reply stating that I ought to go for different lights, energy efficient lights, etc, I have already set my mind on these. Thank you!

My question is this. After researching countless online forums/posts/website there seems to be conflicting information as to the spacing of downlights.

Some websites state leave at least 90-105cm away from the both walls square for the first light to avoid showing imperfections on the wall and then position lights every 1.5 mtr - 2mtrs apart in both directions.

On others it states keep lights closer to the walls between 60-80cm away and then space lights every 1.2mtrs apart.

I even rang Aurora technical helpdesk who said keep them 50cm from walls and then every 1M apart! Sounds like a sales pitch for more light sales to me!

I would really appreciate some common sense advice here guys pls. Not all rooms are square in shape and even widths/lengths!

This lighting will be my primary source of lighting for all the rooms in the house so it is critical I get this right.

Below are the room dimensions of my house;

Master Bedroom 5.57 x 4.02m
Dressing Room 2.27 x 4.02m
Ensuite bathroom 4 x 3.75m
Family bathroom 2 x 3.97m
Rear bedroom 3.15 x 2.68m
Front bedroom 2.68 x 3.89m
Bedroom/Study 2.89 x 2.08m
Upstairs hallway 2.08 x 4.91m
Dining room 3.69 x 4.55m
Porch 1.35 x 2.56m
Downstairs hallway 2.09 x 6.52m
Downstairs WC 1.13 x 1.93m
Kitchen 4 x 5.35m
Living room 4.69 x 7.32m
Garage 5.84 x 2.93m
Loft 4.2 x 5m

Many thanks in advance.[/b]

 

[Aragorn84]

The reason these things are useless, is if you take your bedroom as an example, your 5m x 4m room is going to need anywhere from 4 to 15 downlighters depending on which spacing you use, and the power requirements just get silly.

Our kitchen is perhaps 2m x 3.5m and has 6 of them on the ceiling rated at 50w each, thats 300w of light to illuminate a room just about as well as a single 100w GLS incandescent bulb.

Scale that up to your bedroom at 5.5 x 4 and your talking 12 bulbs and 600w of light, when a single 18w CFL would have done the job.

 

[MandipS]

Hi Aragorn,

Many thanks for your reply. I forgot to mention that my bulbs are 35W equivalent to 50W Halogens.

I guess what I'm after is here is a general rule of thumb to use for everyroom, irrespective of type of room, layout of furniture and requirement of alternative types of more efficient bulbs.

Fact is I am wanting to stick with these downlights/bulbs as opposed to an alternative type of bulb.

Hence, any thoughts?

 

[Chri5]

That's about 80 units (not inc the garage or the loft) x 50 = 4kw for lights

Say 3 hours a day on = 12kw hours x 10p per unit = £450 ish a year.


Thing is they will be banned by the eco police sooner rather than later, could you not stretch to a LED or alternative low energy solution ?

As for location, you will also need to include zones of switching for the big rooms.

So areas that need light like desks, dinner tables can be switched separately to alcoves, features, Tv seating areas etc...

Areas such as bathrooms will want more illumination near mirrors and always above wc's and baths (reading lights).

Go with the manufactures suggestions unless you intend to having a plug lighting system at socket level to add more functional lighting for reading, table areas etc.

Plug lighting via round pin sockets and wall switched masters for each room is very popular and saves a ceiling looking like a swiss cheese. A look that I fear in 2020's will look like the naff 60's decor we all see today.

 

[bernardgreen]

so it is critical I get this right.

Then visit people who have only downlighters. Go in the evening when it is dark outside and then see how the light from downlighters looks in a domestic situation. The owners may not admit they made a mistake so look carefully and thoughtfully.

"" When I sit back and relax there is no where on the ceiling where I can rest my gaze without a bright light burning into my retina ""

 

[MandipS]

Thanks all for the responses so far.

I have discounted CFLs, LED and any other alternative so far because I wish to stick with Halogens. Im not being arrogant here but I am going to use a GET Smart Lighting Intelligent Dimming System for the whole house which only works with Halogens and I obviously do not want to detract from the original request of this post - Spacing of downlights from walls and from eachother.

I note the point on zones of switching in big rooms which is very valid and I will make the appropriate circuit runs for each of the rooms for this.

More suggestions welcome - thanks

 

[Aragorn84]

So what happens to your "intelligent dimming system" when the halogen GU10's get banned?

 

[MandipS]

My bulbs are 35W MR16 12V not GU10s and the Intelligent Lighting Control system can be completely removed via the spotlight cutout holes if ever I need to in the future. My risk I take I know but kinda too late now as already purchased.

By the way here is a copy of my floor plans for your info to give you an idea of my rooms and proprtions - Scale is 1:100. Thank you so far. It's appreciated.

Untitled

• MandipS
• 3 Nov 2009
• 1

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[flameport]

For the most even coverage, the spacing between lights should be twice as much as the space between the light and the wall.
e.g if the room was 2m wide, and you wanted 3 lights in a row between the walls, they would be spaced 50cm apart and 25cm from the walls.

The spacing you actually want will depend on the angle most of the light is emitted from the lamp and whatever you consider to be 'working height' in that room, such as the worktop in a kitchen, desks, tables, or whatever else for other rooms.

Once you have decided on the working height, to get reasonably even coverage from the lights at that height you can calculate the spacing distance using a right angled triangle:
The vertical side is the distance from the ceiling to the worksurface, the horizontal is 50% of the spacing distance between lights (which is what you will calculate). The top angle is 50% of the lamp angle (e.g. 18 degrees), the other is 90 degrees, so from that you can calculate the third angle and therefore the length of the other 2 sides.

To reduce the appearance of darker areas on the floor/surfaces where the light from 2 lamps will meet/overlap, you may want to allow for some overlap of the areas covered by the lamp, as they will be roughly circular, alternatively each row of lights can be offset by 50% compared to the previous row.
If this isn't done, then you will either end up with dark patches where the areas of light don't meet, or over bright areas which are lit from 2 or more lamps. Some of these 'bad' areas are inevitable anyway, as rooms are not usually square or even rectangular.

After all that, you can then calculate the light level at the worksurface for various different wattages of lamp to find the appropriate wattage to provide you with the required light level.

 

[Chri5]

Kitchen an L shaped run along the counter area 800mm off wall, maybe 8-10 lights (subject to under counter and hood lighting arrangements),

Island 4-6 with a bais toward the RHS wall- the counter lights will project on the LHS of the isle.


WC 2 lights, 1 towards the basin, 1 over wc.

Dinning room 8 as :::: with the inner :: and the outer : : being seperate.

Lounge 3 x 4, banks as :: :: ::

Hall 2 main centre, 3 in corridor, 2 infront of porch. Porch 2.


Family bathroom 2 over bath, 2 in wc cube, 2 over sinks, 2 mid room.

Dress room 3 in centre, 1 at each door / access area

Bedrooms- furniture dectates- wheres the beds, beauty table, TV's etc

All beds to have door adj switches and bedside control.

Mid Hall 5, 1 each at stairs base (loft) and stars top (from grd) 3 split across walk area.

Loft and many as you wish, but they will cause issues with celotex insulation, the vapour mebriane and also size issues depending on joist size.


Press the "thanks button"

NB smoke detectors and lights need to be 300mm+ seperation.

 

[MandipS]

CHRIS,

Thank you very much for your reply and I have pressed the thanks button. I have noted your suggestions and thank you once again.

Ive updated the house plan drawing again to give you an idea of furniture layout for the living room, dining room and all 3 bedrooms. Ive also updated the family bathroom layout as I have changed the layout of the bathroom in this room.

I would appreciate your updated suggestions for these rooms also. For the loft I take your point but Ive been told by Building Regs to keep a square foot clear gap between any downlight in the loft and any celotex. I have 9" joists in my loft flat roof ceiling.

The height of all rooms is approx 8 feet/235cm.

Many thanks once again.

Untitled

• MandipS
• 3 Nov 2009
• 1

 

[aptsys]

I would recommend that you choose lamps with a wider beam angle than the ones you've selected. Something like these Osram Decostars:

http://www.lampspecs.co.uk/Light-Bulbs-Tubes/Osram-MR16-IRC_2/M224IR-48865VWFL

Fitted these (or similar ones from Osram) as replacements in my sibling's kitchen 4 lamp fitting several years ago and they're still going strong.

 

[MandipS]

Hi,

thanks for the response. Thing with the 60deg bulbs versus the 36deg bulbs is that they are only 1100 lumens where as the 36deg ones are 2200 lumens.
Standard 50W mains halogens are only 950 max so whilst your suggestion does give a wider light angle and hence less spotlights to fit, the brightness is still the same. I would get over twice the brightness with the 36deg bulbs albeit it shorter angle and more spotlights!

 

[Aragorn84]

Your getting the same amount of light, its just spread over a wider area...

 

[bernardgreen]

Take into account the fact that spot sources directed to the working surface will have shadows caused by people working. Light sources that are diffused or are spot sources shone on walls to produce diffused lighting will create far less pronounced shadow areas.

Reading a book under spot lights is not too bad. Reading a glossy magazine under spot lights can be difficult as the bright image of the lamp is seen in the "mirror" of the page.

But don't take my word without looking at domestic use of spotlights.