Downlight Clearence

[freeman]

Hi Guys,

Just a quick question before i call an electrician in...

i have layed a few sheets of 16mm mdf in my roof ontop of the cross beams\rafters (no idea what u call them), to help clear out some of the mrs stuff out of site (out of mind :D) into the roof ontop of the mdf.

Now im looking at getting downlights put in which would be installed directly under the MDF i have layed down. i understand that the downlights get hot and u have to leave at least 50mm gap between the light\transformer and the insulation etc etc...

Question is, is there rule of thumb\regulation as to the minimum height anything can be placed above a downlight?

at the moment there is approx 150mm gap between plaster and the mdf due to the height of the beams.

Any thoughts\guidence?

[K_S]

Hi Guys,

Just a quick question before i call an electrician in...

i have layed a few sheets of 16mm mdf in my roof ontop of the cross beamsrafters (no idea what u call them), to help clear out some of the mrs stuff out of site (out of mind :D) into the roof ontop of the mdf.

Now im looking at getting downlights put in which would be installed directly under the MDF i have layed down. i understand that the downlights get hot and u have to leave at least 50mm gap between the lighttransformer and the insulation etc etc...

Question is, is there rule of thumbregulation as to the minimum height anything can be placed above a downlight?

at the moment there is approx 150mm gap between plaster and the mdf due to the height of the beams.

Any thoughtsguidence?

I'm not a sparkie but I recently installed a fluoro (or however you spell it) downlight.
$16.00 from Bunnings - get a staff member to open the box and read the install instructions

[seriph1]

hi and welcome to the forum! Personally, I'd run a mile before putting a downlight under MDF. The heat produced is substantial and as it would basically be captive air, could get to flashpoint, in my opinion. LED lighting gives off negligible heat and will still give adequate light. As mentioned, they're available in a lot of places now.

As they say - better safe than dead

:D

[freeman]

thanks for the info guys, ill have a look at bunnings tonight at the LED lights. ill keep you posted.

[Bloss]

thanks for the info guys, ill have a look at bunnings tonight at the LED lights. ill keep you posted.

The Compton compact fluorescent low energy (not low voltage) downlights are $50 for 4 from Bunnings or around $16 separately. They use screw fitting 15W reflector globes (equivalent to a 75W incandescent bulb) and put out almost no heat (15W compared to 50W for a regular halogen downlight plus heat from the transformer. LEDs are available, but much more expensive at present.

Air circulation is the key here - clears space around the fitting is a good idea anyway and there are standard sized shrouds that keep insulation clear by the correct distance.

If I were doing what you propose I would also have a cut-out in your MDF directly above each fitting of about the same size as the cut-out for its fitment in the ceiling (so 80-110 mm or so) so any rising hot air gets away(even off 15W can get pretty warm if there is nowhere for the heated air to escape to).

Note that compact fluoros cannot be used with dimmers - I got around this by using a separate switch wire to each (or in pairs) downlight to control lighting. Easy to do if you have access to the roof space.

Even though the work is not complex, doing it yourself (as K_S says he did) is illegal in all states so you need a sparky to fit the downlights & switches, but there is nothing to prevent you running cabling (if you know what you are doing) and doing the cut-outs etc, but you probably won't save much as the sparky will charge per light point anyway.

The Compton low energy downlights have clear instructions and in my case I had a friend who is a licenced electrical engineer (not an electrician) fit 1m of 3-core 1mm cable to the downlights with a 3-pin plug at the other end. This wiring is simple enough, but unless done by an authorised person is also strictly illegal, but no more difficult than wiring any lamp (such as might be fitted to a turned wood lamp stand).

I was replacing halogen existing downlights the transformers for which are plugged into 3-pin sockets in the ceiling space so this allowed me to do the slightly larger cutouts, install the downlights and then connect by simply unplugging the transformers and plugging in the new light.

This is an easy safe and cost effective way to get low energy downlights replacing halogens, when the switching stays the same. If there were dimmers then legally you have to get a licenced electrician to remove them and leave just switches and also to add any new cabling and switches.

[Bloss]

Just re-read the Compton low energy downlight instruction & data sheet and it says that when the low energy compact fluorescent (CF) lamps are used the only clearance required is 50mm above the fitting otherwise insulation and timber etc can abutt the fitting.

These are standard downlight fittings though - only the lamp itself is low energy and low heat.

If incandescent bulbs are used in the fitting then the spec is for 50mm all around - from any timber, insulation or other building material. These can be as high as 100W so would emit significant heat.

So if fitted with clearance based on using CF lamps then care would need to be taken to ensure that only those lamps were ever used - perhaps by putting a label inside the fitting that is clearly visible to anyone changing the bulb (including any future owners or renters of the house).

[me3_neuralfibre]

Go the CF downlights. I have about 25 of them in my place and love them. Much better than the 3 halogens that I'll replace when i get time.

Paul