downlights

[Cassandra]

We are putting downlights into cupboards and ceiling of our new kitchen. Anyone out there have any advice as to which ones to install? Which ones last longer? Is it a question of the more you pay the better the light?
Thanks
Cass

[ozwinner]

Hi
I bought a pack of 4 low voltage downlights from Bunnies to put in a bedroom and installed them some time ago, 12 months tops.
Now I have to get up in the roof and replace all the tranfomers, I just bought 2, now the other 2 have gone.
I think they are designed to bugger up, so you spend more on replacements. :( :(
I dont think I will get low voltage again.
The price you pay for low voltage you can get some nice 240V stuff, and the globes are cheaper for 240V.
Plus they use the same amout of current to run, so you dont save anything.

Cheers, Allan

[journeyman Mick]

If mounting into the cupboards: there are lights available which are about 30mm thick, they can be mounted into the bottom of your overhead cabinets if you fit a false bottom and router out reccesses. Personally I prefer fluros for work areas like kitchens and laundries. You can fit a pelmet to the bottom of your overheads and mount the fluoros behind it. This will give you a very even spread of light on your benchtops. Even if you fit downlights with wide angle reflectors you will get a pretty uneven distribution of light. Just my .02 worth.

Mick

[wombat47]

Perhaps it boils down to you get what you pay for but my experience with down-lights was not good. We installed them in a timber ceiling - looked great but very prone to over heating - which would cause the glass part of the light bulb to detach itself from the metal holding bit and required a lot of patience and a pair of pliers to remove the metal bit from the holder.

We ended up buying nice round wooden cutting boards with routed edges, large enough to cover the downlight holes, and used them as "ceiling roses" for spotlights.

If you have to have downlights, make sure that

1. there is enough room around the bulb to actually take hold of it,

2. you don't have to buy your bulbs at a specialist lighting shop (or your specialist lighting shop is just around the corner and is open 24/7).

As much as I hate fluro lights, I think they would be much better under the cupboards. You could always fit a light diffuser (be easier to clean too).

[GeoffS]

Cassandra
Can't resist commenting on this one -

Downlights
- the most inefficient form of lighting currently obtainable. The lamps are inefficient (i.e light output for the electricity used) and the lighting patterns formed never seem to be where they are wanted.
- the thought of cheap and nasty transformers lying around in the ceiling makes any electrical worker's blood run cold. Note ozwinner's comments.
- the lamps are expensive.
- a further fire risk comes from the use of low voltage, therefore high currents. Any loose connections are far more dangerous.
- the lamps run very hot and in turn are close to the ceiling or in the ceiling, more fire risk.
- there are other disadvantages which I can't think of at the moment!

I'd go for candles for both efficiency and safety.

Cheers

[SteveI]

Cassandra

Like the others - also found experience with halogen downlights a bit problamatic - they are great for accent and give an intense light, but the bulbs don't last as long as you might like. (& at $5 a pop it adds up)

Some of the newer transformers give better life because they run at 11.5 volts, greatly increasing bulb life (that .5 volt does make a difference).

We found in hot weather the transformers would switch-off with the heat overload cutoff and take 15 minutes to cool down and come back on..... again the newer more expensive models are more stable.

The heat off the halogens also adds to discomfort in summer

I would go for the bigger 240 volt downlights that have a reflective tube and use the energy saving bulbs - cooler and last longer - the downside is they take a while to come to full brightness.

Pity because I do find the light of the halogens better - especially with the eyesight not as good as it used to be.

[bitingmidge]

Halogen has it's place! The newest incarnation of the Home of the Biting Midge has ONLY 12v downlights except for fluoro's in my workshop, and a couple of IR bathroom heaters. We have 80 of the suckers including exterior lighting..

I never thought I'd see the day......

I took advice from a couple of electrical engineers who specialise in residential work. A couple, because I didn't believe the first one so got a second opinion.....

Don't buy the cheapest fittings you can find. Good ones are designed to ventilate and dissipate heat. Use only one transformer per light fitting, and put dimmers on every circuit. If you drop back the power to the lights by about 15-20% you will find you have a much softer light, and apparently the darned things run 100% more efficiently.

I don't pretend to understand the theory, but a 12v system is also more efficient electrically, taking into account the transformer losses, apparently consuming about 20% of the power of the same output incandescent. (I would appreciate some learned help on this one!)

The "uneven" light referred to from downlights can easily be overcome by using more of them if necessary, but in a kitchen you really don't need to light any more than the bench tops and you'll easily have enough to see everywhere else. We have one over each side of the sink, another above a large counter space and four built in to the range hood. (Total seven, but the range hood ones are rarely all on at one time, and don't dim).

As per Mick's advice, there are a number of fittings designed specifically for bulkheads and which need as little as 35mm clearance. You will need somewhere to place the transformer, and make sure that you do install them in accordance with the manufacturers recommendations. Heat build-up will kill the globes!

We haven't experienced any problems with transformers, globes, overloading etc, but didnt' take any shortcuts in installing either.

Glad to add to your confusion!

Cheers,

P

[Theva]

Cassendra,

I am with bitingmidge on this one.

Advice on 12V globes. The best in MHO is OSRAM.

Top of the range globe alone costs app $17.00 trade price.

details- 50 or 35W, 60deg beam angle, IRC type 50mm dichroic, part no: 48870VWFL or 48865VWFL.

Lasts for years. Their matching electronic transformers (HTM range) works fine up to 50 deg.

Mounting under cupborad - 20w bi pin lamps with housings.

Hope this is of some use.


Regards,

Theva

[GCP310]

Get in contact with a cabinet supply company, they will certainly have a product to suit your needs. off the top of my head, try Hafele, they have a whole range that is designed to be routered into 16mm melamine board.

Goodluck

[MF3106]

Just my two bobs worth.

We had good quality low voltage lights fitted in the kitchen about 5 years ago - total of 15 in all. We had an electician supply and fit units of good quality - and have only had two globe losses and one transformer replacement.

Also they now apparently have electoronic transformers - very small, and low heat output.

Hop this helps

[glenn k]

My electrician told me not to put insulation between the rafters in a cathedral ceiling as it would cause the transformers to overheat. My comment was why insulate at all then. We decided to insulate and put 12v spot lights mounted on the transformer. He also told us not to put dimmers on 12v lights as the globs blow quicker. It didn’t make sense to me at the time and still doesn’t now, I may add dimmers one day if only to reduce power consumption.

[Cassandra]

GOLLY GOSH!
Thanks so much for all the advice. While I prefer those fluro lights that have the large difusers over them (such good lighting) I am going with the downlights because of style. It is a 50 sq.m. kitchen so I will use 15 downlights. Thanks all for your help on this. I'll let you know how it looks. If I can figure out how to post a photo, when all is done I will do so.
Cass

[ChrisH]

Cass

15 lights at 50 watts each is 750 watts. That is three quarters as much power, and heat, as a single bar radiator. that is a LOT of heat to dissipate. It is also a real lot of wasted energy.

I don't wish to be rude but that is really a silly choice.

If you imagine that twenty years ago before we had so many options, a 100 watt light globe was considered "bright" for any room in a house, you are now talking about seven times the power consumption. The reason is that these little halogen spots light up a very small area, as they have such a narrow beam. So you need lots of them to light up a room. They are good for lighting one small thing, like over a stove. Think about why they are called a SPOT light. They are trendy becaue they give a stark white light but it is not a smart choice. If you want to illuminate a long thin area like a kitchen work area, then use a long thin light. (eg a fluoro). Fluoros use about a fifth the power for the same light, and don't have the high waste heat generation. You could still have great looking lights, by recessing the light into the base of the cupboard, so all you see is a glass panel set into the base of the overhead cupboards, perhaps with a stainless steel surround. A fluoro doesn't have to look cheap and dorky. You can get fluoros in different shades of light, commonly "cool white" and "warm white" depending on if you prefer a stark white light or a mellower, more yellow light.

Spots in a ceiling are even worse in a ceiling than in the base of a cupboard, as every light fitting needs insulation removed from over and around it so it doesn't cook or cause a fire. So your heating/airconditioning system has to work harder to cope, as the spots are effectively a bunch of holes punched in your ceiling. So with downlights you lose two ways, by their own inefficiency and by the need to ruin the insulation in your ceiling.

You will hear the halogen lights called "high efficiency" which is true in a sense - a halo globe does produce a little more light for the same energy than an ordinary incandescent globe, though not much. Fluoros are the one that use 20% the power of a standard globe, not halogens. Fluoros use much less power than halogens for the same light, and spread it around more evenly if used in an appropriate fitting.

I live in a solar powered house so I have to watch my power consumption, all my lights are compact fluoros except one - the bedside light is a 15w standard globe, as the smallest compact fluoro (5w) is still too bright!

Best wishes
Chris.

[Theva]

Cassandra,

Well, it is your choice.


Few pointers on ceiling mounted downlights:

1) as per previous posts, always use a dimmer. Use electronic transformers compatible with the dimmer (leading edge / trailing edge). Run them on full power once in a while (say monthly) for longer globe life.

2) typical good quality fitting costs $10 to 15 without transformer/globe. Centre tilt type is better than fixed type for heat dissipation because of the small gap around the globes.

3) Keep the transformer away from the fitting (min 200mm), remove insulation around the fitting as per manufacturers instruction. Else, if there is a fire by any chance, there will be insurance issues.

4) For cupboards - undershelf mounted lights (eg: Crompton’s DL 888 range). They are 25mm deep, 80mm dia, can be recessed, some comes with a switch.


Hope this is of some use.

Regards,

Theva

[jackiew]

If you're set on the downlights have you thought about how the lights are going to be switched?

will you need all 15 of them on at the same time always, if you aren't working in the kitchen but just need to find your way to the fridge for a beer you might just want to be able to turn on a couple of lights.

And as someone who has lived in a couple of places where I've had to grope across the room in the dark to a light switch because it was located near the other entrance to the room think about two way switching ... well worth any extra expense.

[Cassandra]

Well, Thanks to all of you for the advice.
I went for fewer downlights, and less wattage than planned. Even the sparky said 15 was too many. I ended up with 12 in an "L" shaped kitchen but on 4 circuits. Only 5 of them are actually in the kitchen part. The rest are the hallway, desk or pantry areas. Hubby is up there painting as I type. Floor goes in tomorrow and then the fridge and d/w. After that we're ready to use.
Thanks again,
Cass

[MrFixIt]

Hi GeoffS
Originally posted by GeoffS
Cassandra
Can't resist commenting on this one -


I can't resist commenting on your comments javascript:smilie(':)')



Downlights
- the most inefficient form of lighting currently obtainable.
The lamps are inefficient (i.e light output for the electricity used)


No, they are actually more efficient than normal incandescent globes. They output more of a "whiter" light than a normal globe at the same wattage rating!



and the lighting patterns formed never seem to be where they are wanted.


Well that's not a problem with the light! That's a problem with the installer/designer.



- the thought of cheap and nasty transformers lying around in the ceiling makes any electrical worker's blood run cold.


Sure does, that's why good quality transformers should be used. The original "linear" transformers were prone to generating some heat and cheap ones would fail prematurely. However it is well worth paying the minimal extra cost for the "switch mode" transformers. These work in the same way as the power supply in a computer. These are _efficient_ and run cool. There is almost no loss via transformer heat etc.



- the lamps are expensive.


Yes, but the owners of downlights (those that like them) don't mind paying a little extra for the benefits _they_ perceive.



- a further fire risk comes from the use of low voltage, therefore high currents.


Yes, maybe but the risk is minimal, providing they have been "intelligently" installed.



Any loose connections are far more dangerous.


What LOOSE connections. There should be NO loose connections anyway!!!! Whether or not it is 12v or 240v!



- the lamps run very hot and in turn are close to the ceiling or in the ceiling, more fire risk.


Correct and thoughtful installation will reduce the fire risk to nothing more than ANY OTHER light.

I think many of your comments are misleading to others.

I have installed a variety of downlights in my home, including in a SOLID timber ceiling (which is the floor of the room above) I will post details and maybe some pics, in a subsequent message. Hopfully this will help potential other downlight users.

It only takes a little bit of thought beforehand to achieve a great lighting setup (BTW I am not a lighting designer, I am a very capable handyman).

Regards

Peter

[MrFixIt]

Hi all

Please excuse the long message. It contains several quotes that take up space. I wanted to reply to several comments in various posts, so I combined them all into one message. (I hope I got all the quote highlighting correct)

Kind Regards

Peter


I think they are designed to bugger up, so you spend more on replacements.

Cheap halogens will not last as long as a quality unit - you get what you pay for!


If mounting into the cupboards: there are lights available which are about 30mm thick, they can be mounted into the bottom of your overhead cabinets if you fit a false bottom and router out reccesses.

They are available as small as 15mm x 55mm. Forstener bit or hole saw can easily create the opening required.


Perhaps it boils down to you get what you pay for but my experience with down-lights was not good. We installed them in a timber ceiling - looked great but very prone to over heating

I have installed eight 20watt halogens into my SOLID timeber ceiling - no problems.


Some of the newer transformers give better life because they run at 11.5 volts, greatly increasing bulb life (that .5 volt does make a difference).

Hmmm? This actually increases the current (amps) drawn through the wiring and throught the globe's filament. Given all things "electrically" speaking any addtional current though the globe would tend to decrease the life of the globe. If these halogen globes were to run at say 24v, then the current would be halved and the globe's lifespan _should_ increase. However there are many oher factors involved in the lifespan of a globe :-)


We found in hot weather the transformers would switch-off with the heat overload cutoff and take 15 minutes to cool down and come back on..... again the newer more expensive models are more stable.

Generally speaking the "more expensive models" are switch mode transformers. These are an "electronic" transformer they have circuitry inside them to control the output. They do run almost cold to the touch. There is a small disadvantage with this type of transformer in that it requires a "load", ie some wattage to actually run. Now however this is an ADVANTAGE in the use of downlights, if the globe fails then the transformer does not "switch on". It therefore does not waste electricity heating itself up as would the linear (older style) transformer :-)


The heat off the halogens also adds to discomfort in summer

This is a perception of heat. ANY 50watt globe puts out the same amount of heat. I mean 50 watts IS 50watts the difference is in the current used to create those watts!
You _may feel_ the heat more as the downlight concentrates the light and therefore the heat in more of a beam than normal incandescent lighting - however the heat is the same.


I would go for the bigger 240 volt downlights that have a reflective tube and use the energy saving bulbs - cooler and last longer - the downside is they take a while to come to full brightness.
Pity because I do find the light of the halogens better - especially with the eyesight not as good as it used to be.

They are cooler as they are usually of the flourescent type. This is also the reason why they last longer. A 20watt flouro uses the same amount of current as a 20watt halogen globe. The big difference is in the spread of light - oh, and the "whiteness" of the light (degrees Kelvin).


Hi BitingMidge
Don't buy the cheapest fittings you can find.

SOOOO true!


Use only one transformer per light fitting,

Not necessarily! You can obtain 105watt rated "switch mode" transformers and these can run 2 50watt halogen globes. Or you could, as I have, run 5x 20watt globes - WORKS GREAT for me!


and put dimmers on every circuit. If you drop back the power to the lights by about 15-20% you will find you have a much softer light, and apparently the darned things run 100% more efficiently.

100% more efficiently is bit out? Though they do use less current when dimmed therefore your electricity bill (efficiency?) is improved.


I don't pretend to understand the theory, but a 12v system is also more efficient electrically,

50watts of electricity is STILL 50 watts of electricity no matter how is is used. However the light output for a halogen globe at 50watts is brighter (whiter really) and more concentrated (directionally) than a normal 50watt incadescent globe. As this "whiter" light is reflected and concentrated into a "beam" the light is more efficient in _light output_.


As per Mick's advice, there are a number of fittings designed specifically for bulkheads and which need as little as 35mm clearance.
FYI There are some light fittings - specifically designed for cabinet displays - that are only 15mm high and need an opening of 55mm and allow a MAXIMUM of 20watt globes
[quote][b]
You will need somewhere to place the transformer, and make sure that you do install them in accordance with the manufacturers recommendations.

FYI Some of the newer switch mode power supplies allow up to 4 METRES between the globe and transformer - I assume that they are designed to provide a slightly higher output to make up for the voltage drop over that distance (at high current 4-5amps). If anyone decides to implement a distance such as this, please use larger cable, it helps prevent voltage drop and the drawing of more current.


Get in contact with a cabinet supply company, they will certainly have a product to suit your needs. off the top of my head, try Hafele, they have a whole range that is designed to be routered into 16mm melamine board.

Sometimes (most times?) the cabinet supply companies are a little overpriced for such items. Try some of the electrical wholesalers. I found Laurence & Hanson very helpful. I purchased via L&H 10 cabinet style halogen fittings (opening size 15mm deep x 55mmwide) for $10.00 each including a 20watt globe. Two 105watt electronic transformers will power all of these. Quality 105watt transformers are available for approx $25.00 each.

You may be amazed at what can be achieved with thoughtful use of these fittings - pics wil follow in another message.

again...

Regards

Peter

[zathras]

Originally posted by MrFixIt

FYI Some of the newer switch mode power supplies allow up to 4 METRES between the globe and transformer - I assume that they are designed to provide a slightly higher output to make up for the voltage drop over that distance (at high current 4-5amps). If anyone decides to implement a distance such as this, please use larger cable, it helps prevent voltage drop and the drawing of more current.



Ahh, assuming your transformer is constant voltage, introducing extra series resistance in excess wiring will reduce the current flowing not increase it. You WILL waste power in the wiring (volts dropped x current), the net effect being less voltage available at the bulb, which relates to less power and hence a dimmer light.

The voltage drop can only be minimised by larger cross section cable, but never ever prevented, (unless of course you have a superconductor and liquid nitrogen handy)

IMHO Halogen lighting is over-rated, watts is watts. Low voltage does not mean low power dissipation, it means high current.
Low voltage wiring can be a more serious fire risk simply due to the currents that are flowing. A poor connection at 12V will get much hotter than the same connection at 240V and the same wattage load (power = current * current * resistance).

The electricity companies use 220,000 volts in their distribution networks to help keep the current down, less current, equates to less power wasted in the high tension cables. The high voltages of course have their own problems.

[MrFixIt]

Originally posted by zathras
Ahh, assuming your transformer is constant voltage, introducing extra series resistance in excess wiring will reduce the current flowing not increase it. You WILL waste power in the wiring (volts dropped x current), the net effect being less voltage available at the bulb, which relates to less power and hence a dimmer light.

Yes, I was assuming that the newer switch mode transformers can maintain a constant voltage - something like this must be implemented within its design, as the supplier makes a point of pointing out this 4 metre capability.


The voltage drop can only be minimised by larger cross section cable, but never ever prevented,


Of course, this is why I stated such in my previous message

"If anyone decides to implement a distance such as this, please use larger cable, it helps prevent voltage drop and the drawing of more current."

Kind regards

Peter

[MrFixIt]

Hi Again

After rereading my message and the ...
"If anyone decides to implement a distance such as this, please use larger cable, it helps prevent voltage drop and the drawing of more current."

...part I realised that I SHOULD have written helps MINIMISE voltage drop, not "prevents" voltage drop. Wrong wording :-)

Kind regards

Peter

[soundman]

12volt Dichroic lamps are a wonderfull thing and are an excelent choice in their application.
such as feature spots, lighting art & garden lighting.

they are reasonably efficient and have good colour temperature.



BUT as a general source of houshold illumination they are dreadfull.

they have a bright white(ish) light that is strongly converged and tightly confined.

they are mostly used because they are cheap and easy to fit, and provide a flat cieling finish.

You can put 10 of these suckers in a kitchen and have a poorly lit kitchen wher ONE (thats "1") 40 watt fluro would do a much better job.

for good confortable houshold lighting you need a portion of direct and a portion of reflected light, all of dhich should be difused.

Down lights of any form would have to be one of the most frequently and worst applied building product of all time.

have a look at a nice circular fluro oyster fitting.

Hate down lights die die die!!!:mad:

If you want irritating poorly difused, glare filled, expensive to run lighting, install dichroic down lights.

A 50 watt dichroic down light is equavalent to an 80 watt portaflood.
would you put 10 portafloods in your kitchen???

Dimming halogen lights.
Halogen lights do not like being dimmed, they are designed to runn hot (too complicate to explain "the halogen cycle"). If you dimm them below about 85% capacity they willl blacken & die early.

better to use a wider angle lamp and a lower watage.
there are 4 availeble beam widths and 20 and 50 watt versions.

did I say i hate down lights.

[bitingmidge]

So Soundman hates downlights!! ;)

While we are all entitled to our views on what does or does not constitute good lighting design, a couple of statements above cannot pass unchallenged!

1) Of halogen lights:- "They are reasonably energy efficient". I don't pretend to understand the maths, but most catalogues claim a reduction of up to 75% over an equivalent wattage incandescent without dimming. I guess consuming a quarter of the electricity is "reasonably efficient" so can't take you to task! Certainly they are not as energy efficient as fluorescent fittings, but there are certain ahem...aesthetic considerations here as well!

2) Dimming. The attached image is from the OSRAM/sylvania catalogue. A search of any manufacturers catalogue will show similar figures. Basically these indicate that significant savings and increases in lamp life can be made by reducing voltage slighthly. Beyond 80% the graphs flatten out, and below about 30% the lights don't seem to operate. Effective dimming visually is usually in the 80-90% range which is enought to soften the harshness of the light.

3) How many FLUOROS are equal to an 80w portaflood, and who cares?
As I have said in an earlier post, we have three (3) halogen fittings in our kitchen apart from the light over the range hood, and have no lighting challenges. I guess it's just a case of paying for the right advice rather than experimenting! The lighting is not even, but provides sufficient task lighting for all preparation and cleaning tasks. Two more fittings would have evened the lighting pattern, but we don't need five Portafloods in our kitchen!! ;) (sorry!!)
No glare, no diffusion, not expensive to run.

4) Fluorescent fittings:
I've never seen a "nice" fluorescent" fitting!!:D :D And I love the control one gets over lighting levels and the green tinge to the meat unless one uses daylight globes which make everyone look artificially suntanned.

Did I say I hate fluoro fittings??

5) "they are mostly used because they are cheap" AHA! The crux of the issue.....DON'T use cheap if you want a flexible lighting solution that you can enjoy. Cheap will pretty much achieve all the negatives you claim, and will save as little as $20 per fitting.

Yes they do provide a flat ceiling finish, which in itself is reason to consider them in some installations.

Finally.....if you fitting out a seriously retro house or are stuck in a 60's time warp, use fluoro's everywhere. (We used to do these wonderful pelmet fittings covering 40w tubes). If not, I suggest you do a heap of research and you'll find as I did recently, that times have changed and there are newer flexible solutions!

Cheers,

P

[Theva]

Well, Every beast to its own devices.

Few comments on low voltage halogen lamp life:

1) good quality electronic transformers increase lamp life by limiting initial current.

2) Running lamps on full power once in a while helps with the halogen cycle and reduces lamp blackening / redepositing tungsten on the filament thus increasing effective lamp life.

There are florescent lamps / fittings with all the features of low voltage halogens. But they are much larger (160mm dia, 200mm deep), much more expensive and require 10V dimmers and associated control gear to match LV halogen's features. More appropriate for commercial applications.

Regards,

Theva

[bitingmidge]

My apologies if I seemed grumpy in the above post! Seems I write grumpy early in the morning.......grumpy not intended.

Thanks for the advice re running at full power once in a while...can't say that I've ever experienced lamp blackening but will watch out with interest.

Cheers,

P

[soundman]

All light fittings have their place (some that place is the bottom of a skip) the most commom problem is the failure to design (at all).

Most lighting fitting selection is not basses on performance but on appearance or other factors.

There is a big backlog of bad feeling toward the fluro due to bad application in the past dating back to the 50's.

In years to come the same unjustified bad feeling will apply to down lights for the same reasons.

Big mistakes with down lights.
they are not suitable everywhere.
too many
too bright
too close
no difuser fitted
fitting selected on appearance turned off.

improvements in fluros
better selection and quality of colour output
longer life
better efficiency
no longer contain mercury ( well shouldn't)
more shapes & forms of lamp available
much better range & quality of fittings.
fluros are more efficient than most other forms of houshold light

any body who puts up a basic straight fluro in a nice house should be slaped arround the ears with a stale mullet.

remember the old fashoned light bulb still has a place and may still be the best choice in some situations.
they have a warm colour temperature
tolerate dimming realy well
burn in any position
are cheap as chips
come in a vast array of shapes, forms & wattages.

I waiting for some of the new foprms of light to mature.
high intensity led looks very promising.
electro-luminessent panels & wires could be very funky.

I'm not a real fluro lover either but they still produce the all round most usefull light for domestic applications.

cheers

[glenn k]

[QUOTE]Originally posted by MrFixIt

Hmmm? This actually increases the current (amps) drawn through the wiring and throught the globe's filament. Given all things "electrically" speaking any addtional current though the globe would tend to decrease the life of the globe. If these halogen globes were to run at say 24v, then the current would be halved and the globe's lifespan _should_ increase. However there are many oher factors involved in the lifespan of a globe :-)


This was in response to 11.5v increasing globe live. This is right more voltage more current though globe shoter life. 24v thought same resistance twice current glob dead.

[ChrisH]

biting midge

Which catalogues claim that halogens use 25% power for the same light output?
This is just plain wrong.
Halogens use fractionally less power for the same light output as a standard incandescent, but it is very marginal and does not include transformer losses (which are also quite small in the switchmode transformers.)
So overall the halo and the incandescent are about the same for energy efficiency. Except that downlights require ventilation artound them to stop them cooking, which means holes in your ceiling insulation, so your heating and cooling costs are higher.

The technology of a halogen is basically the same as incandescent, except that the halogen gas allows the filament to run hotter, so it produces a whiter light. A standard incandescent could be designed to burn that hot and it would produce just as much light, but it would soon burn out.

Chris.

[MrFixIt]

Hi

Just a quick post to let you know I have updated my home page. A rare event <g>. The update shows images of some of my "shelf" or cabinet lights in use as down lights. The images do not convey the lighting effect very clearly, in that the images are not as bright as I would have liked. Please bear in mind that in real life the lighting is very good. (Some of the links do not work correctly, however you should be able to see all of the images via clicking on the thumbnails).

Please feel free to ask any questions and I will help in any way I can.

Go here

http://www.multiline.com.au/~psanders/Woodwork/woodfram.htm

and click on downlights

or Mobile base if that interests you.

Kind regards

Peter

[Iain]

We ahve just installed 240v halogen 'spot' lights in our kitchen to illuminate the areas that the fluoro misses.
They are like 4 little super troupers on a stainless track and rated at 50w each.
Given they are directional I found I was able to direct two to cover a wide area without creating a shadow when standing in front of the light.
Admittedly the setup cost in excess of $200 but the little lights work well and with their own little UV shields do not create a sunburnt neck problem.
I can feel the heat on the back of my neck but it is not 'that' hot, and at my age, almost therapeutic:D
I wired them in to the normal circuit and they are switched with the centre switch on a two outlet power point, this is probably safer than the lighting circuit as there is a circuit breaker, earth leakage detector on these circuits.
The lamps are about $5 each and come with their own reflector and lense.
We only use the lights when ligyt is low and we are working at the kitchen benches.
Just my 2.2 cents woth incl GST.

[bookers]

I agree with Theva.
As a lighting engineer and working in the industry for 15yrs I hope I know what I'm talking about. If your heart is set on the aesthetics of the downlights we can't change that! So we find the best solution.
1. Electronic transformers consume less power themselves. Create a soft start on the lamps and and regulate the power better than the old BLACK ironcore ones. Also no heat problems in ceiling!
2. Steer clear of cheap import T/Formers. Stick to Osram, Atco, Philips or Vossloh versions. If there is a problem you can easily get backup service.
3. Lamps. Osram do their IRC lamp, Philips do their Masterline ES lamp. Both lamps use a special coating on the reflector to dissipate heat and create MORE light. Therfore a 35watt lamp produces the same amount of light as a normal 50watt. SAVE POWER. Also these have longer lamp lives approx 5000hrs. Although are more expensive.
4. The fittings themselves are a dim a dozen. They are only a diecast housing. It makes no difference at all.
5. Never buy fittings or lamps RETAIL. Stick to where the electricians buy them. Electrical wholesalers! Being based in Sydney try John R Turks, Lawrence & Hanson, TLE, etc. There's plenty in the yellow pages. All the retailers generally import their own product so if something goes wrong in SOME cases you're stuck!

Hope this helps

[GeoffVIC]

We found in hot weather the transformers would switch-off with the heat overload cutoff and take 15 minutes to cool down and come back on..... again the newer more expensive models are more stable.



AAahh!! *figurative light bulb goes on....* pun intended :D

I have one downlight (out of 8) that is doing that... turning itself off at intervals, and then turning itself on again a little while later. I wondered why - heat protection may be the answer...

Would simple aging of the transformer also show this behaviour? The lights pre-date my ownership of the house - my guess is they were installed about 5 years with a kitchen renovation.

We just re-wired the whole house a couple of months ago, so I'm comfortable with the general electrical state of health.

(It's nice now to have earth wires on all powerpoints and non-flamable cotton-wrapped wiring...hehehe! :D :D
The safety switch earth leakage device makes me feel all warm n fuzzy inside now too. Makes it a little easier looking at the dent in the bank balance as a result.)

Cheers,
Geoff

[bookers]

Geoff,

The older ironcore(wire wound) transformers have a built in thermal cutoff. Obviously once the temperature reaches a certain level they shut off. This will be definately more common during warmer weather. Also insulation surrounding the T/F will increase the heat and the placement of T/F directly in line with your downlight will effect also as the radiant heat from the lamp is sent backwards through the ceiling. The easiest fix is to replace with the Electronic option which will dramatically reduce your problems. The 'cycling' effect of these T/F is purely due to heat. Australia's largest T/F manufacturers are slowly weaning themselves off these types purely for that very reason. These things were built to a price!;)

[MrFixIt]

Hi

FWIW, I now use only the electronic (switch mode) transformers. At least now they are moderately priced.

When I was using the linear (iron core) transformer I ALWAYS mounted them vertically ie on a rafter or similar, this way the transformer body was on the side of the rafter (the longer direction pointing upward). I also added a "spacer" between the transformer and the mounting surface. The spacer was usually just a small 2x2x1cm block of wood. This allowed full air circulation around the complete transformer.

One othe point to consider with linear (iron core) transformers is that they are always using *some* electricity. This can be proved by feeling the temperature of the transformer body even when thelight is switched off - it is usually warm. This is a fact of life.

Electronic transformers do not use anything significant until they are under load

[Theva]

Hi,

John R Turk can get you most of the stuff but they normally deal in regular sparkey type of goods.

If you are after trade type lighting / globes etc, possible sources include Sydney Lighting ( 98318000, Blacktown ). They do counter sales.

Regards,

Theva

[Danster]

Just a quick question...This thread has made interesting reading.
I just replaced a dangly 100w light fixture with a $12 halogen kit from Harvey Norman Lighting.
Looks great and pretty easy to install.
Question. The old fixture used the earth cable. The new transformer only has a place for the +ve and -ve. What do I do with the earth (green/yellow)?

Secondly, the actual light sits under a pad of insulation. I guess I should cut a (say 10cm) hole in the fibreglass wad for ventilation? The transformer is just sitting on a nearby rafter about 12-15cm away so its not under or on top of the fibreglass insulation.

I don't want to start any fires by dodgy electricals, but on my extreme budget, can't afford a sparky to do it and I'm a fairly capable handyman anyway.

cheers

[MrFixIt]

Hi
Question. The old fixture used the earth cable. The new transformer only has a place for the +ve and -ve. What do I do with the earth (green/yellow)?You do not (usually) use the earth wire on a low voltage downlight transformer as the transformer is (usually) double insulated. Double insulated electrical items do NOT have an earth wire. In your case I would fold the earth wire away from the light/transformer and use some insulation tape to bind it to the outside of the electrical cable. This will leave it available for any potential (though unlikely) change to a light fitting that does require an earth connection.

BTW +ve and -ve normally refer to DC voltage, ie the OUTPUT side of the transformer, NOT the AC input side. You could refer to the AC input side as "~", you will see a similar symbol on many ac inputs. Ususally a "double" version like a "wavy" equals sign.


Secondly, the actual light sits under a pad of insulation. I guess I should cut a (say 10cm) hole in the fibreglass wad for ventilation?Yes, that is a good idea. 12v halogen globes run VERY hot and insulation coverage like this would increase the temperature of the light/fitting and shorten the globe life (which can be short enough already :D)
The transformer is just sitting on a nearby rafter about 12-15cm away so its not under or on top of the fibreglass insulation. That's ok. If you have the "older" style (linear) transformer they do tend to get warm but this is not normally a problem. If you gave the newer style (switch mode or elcetronic) transformer then these only get warm when the light is in use.

[Dan]

Hi

One othe point to consider with linear (iron core) transformers is that they are always using *some* electricity. This can be proved by feeling the temperature of the transformer body even when thelight is switched off - it is usually warm. This is a fact of life.

Electronic transformers do not use anything significant until they are under load

Sorry, but I don't agree. The switch for the light circuit is on the input side of the transformer (240vac), therefore the transformer can't use any power if it has no input ie, when the lights are turned off.

[Wildman]

This is one of the most polarised posts I have seen so far on this board so I will throw in my 2c worth. The missus and I love the downlights and are very happy with them. The 12v lights really brings out the timber floors and makes the place fell nicer compared to the old lights. We did make the mistake of the iron core transformers which cut out sometimes and also have had times when the dimmer caused the filaments to hum but since getting good bulbs we havent had any problems. The most common bulb to come in a package is the Luxman and they are the ultimate in useless. We were having one blow every 2 weeks (19 in the house in total). We tried a number of brands and settled on NEC bulbs which are cheap (compared to osram, I paid $3.80 each for 20) and we have only had one blow in the last 18 months. We use the 60 degree lights to give quite even lighting and we thought about the light placement so dont have any issues with them. I replaced the hottest transformers with electronic and have had no problems since. Our new renovation (starting in 6 weeks) will definitely have 12v downlights again.

Cheers
Wildman

[Theva]

Danster,

Earth wire
As per regulations (AS 3000), earth should be brought up to the transformer, you can fold it as MrFixIt advised or cut it off just outside the transformer.

Insulation
Make the hole in the insulation at least as large as the ceiling cutout hole required to install the fittings.

Regards,

Theva

[Tip hunter]

My two cents

I love my dimmers set near the bed in each room with an off switch on the same plate. Get in to bed and dim to read then off without getting up.

A single light source in a kitchen is terrible. Everywhere you work you are in your own shadow. Hot lamps under a cupboard are not my go however. Set a channel in the overheads for a flouro keeping the line underneath neat.

In a roof keep insulation and bugs away from halogens with a cheap terracotta pot. Cut a cross shaped slit in the insulation and put a pot over the light. Silicone some fly screen over the hole on the pots bottom to avoid even the smell of roasting bugs. Little cheap pots at bunning are only 75cents last time i got some and are not at all heavy. Easy way to avoid smouldering smells.

[Gumby]

To bring this topic up again, Ive just had 4 12v downlights put in my son's bedroom. We are in the process of painting and have the lights 'popped' down away from the ceiling. There's a buzzing noise coming from the transformer/s which is annoying. If i put all the lights back into their sockets it's harder to hear the buzz but it's still there. Is this normal (we've never had them before and have ordered 12 more for the rumpus room but if i have to put up with the low buz, I'm going to cancel the order)

[soundman]

different transformers may solve your problem some are noisier than others.

are the transformers sitting straight on the cieling panel. screwing or hanging them from the joists may shut them up a little.

[macca2]

I am starting into the kitchen renovation bit and have had 6 12v downlights in the plan. 3 over the work bench area and 3 over the cooktop/oven area.
My question is if I use 60 degree lights over a 900mm bench with a 2.4 ceiling height, how far apart should I place the lights for an even spread of light on the work area.
My retailer said, " they all come out of China and none are better than others"
Is this true.
He quoted me $13.95 for complete light,bulb,transformer kit. Lights are non swivel white powder coated. How's that???
Lastly are dimmers the go??

Thanks

Macca

[Gumby]

different transformers may solve your problem some are noisier than others.

are the transformers sitting straight on the cieling panel. screwing or hanging them from the joists may shut them up a little.

Thanks for the tip Soundman,

I can't put them on the joists because I can't get in to the roof. We have a flat roof with only about 30 cm roof cavity between the plaster and the colourbond. That's why they have them sitting on the plaster. I can put my hand in the hole and unplug each light and also get the transformer out if I want to.
I've just cut up some rubber underlay we had when we pulled up the carpet. I've got each transformer sitting on a piece of that cut to the right size so it's sitting on a soft rubber cushion. Turned them on again and no buzzing sound at all. Problem solved - but I'm going to insist on better quality for the rest of the house.

[soundman]

would prefer to see a more flame retardant material than rubber underlay for such a purpose.
electrical components should not fail in a ball of flames but I'm a sceptical type & hey stuff happens.

[Gumby]

Yeah, I agree. I think I'll cut them up very small so that there's just a tiny bit under each of the 4 feet. Same result, less risk. Thanks

[TassieKiwi]

Downlights IMHO are only any good for work areas when you are looking down - bathroom bench, kitchen. I had a couple of the thin ones under a cupbpard unit, over a bench. Awesome here. Otherwise I hate the Ba5tard5. They shine on your eyes in any room, and if you have spectacles this is worse. Expensive. The dimmer makes the TV buzz. When you replace them, dead bugs fall on you.

The wires pull out of the transformers.

Trendy though. If you're watching the pennies, you can buy one that takes standard globes max 75W, mounted horizontally. We had about 12 of these in the house, and they worked fine. About $11 each+globe. No transformers or any of that flash gear.http://www.woodworkforums.ubeaut.com.au/images/icons/icon10.gif

[MarkV]

Well what an epic post !!! I might as well add my two bob's worth eh what :D

Mr Fixit covered it all pretty well I thought and I thought I would let you know my experience. The 240V downlights I installed sucked kept blowing bulbs and the bulbs were dear as poison about $13.50 from memory. Went back to the low voltage ones like we had down south no probs to date and it's been about 2 years. I have just installed 4 low voltage ones in the lounge room (Pierlite brand) $18.60 each with a 50 watt 60 degree bulb. The dimmers are on order as the lights have electronic trannys and require trailing edge dimmers and they only had the iron core leading edge ones in stock . The dimmers are a bit exxy about $35 as opposed to $32 for the old style. SWMBO is very happy with the lighting as they are situated in pairs over each of the lounges and with the dimmers installed next week should be even nicer. I intend to install them throughout the house as I renovate it all as I find that they give me light were I want it and look cool dimmed for moodlighting.

[Markw]

Two cents is no longer legal tender - here's my 5 cents

When I purchased my house about 6 years ago, it already had Martek brand 240v 60w down lights in the master bedroom with dimmer and in the hallway. The bulbs were standard BC reflectors and still easy to obtain. The bedroom lights are still there and they provide a softer lght than the current down lights which is good. These lights may have to be replaced with halogen downlights if I can't get any more of them as this room is due to be increased in size.

The hallway was recently painted along with new doors and frames and I decided to remove the existing Marteks and replace with 240v halogen down lights. These are Neilsen branded fitted with internal glass covers. 2 have already blown and the heat output is high. Stand under for too long and you will get hot. Unfortunately I have also put them in the reno'd office - again too hot and summer is coming.

When the kitchen was reno'd I put 12v glass covered down lights in and the heat output has changed dramatically. From 1/2 metre away you can barely feel any heat output. Again I have consumed a few globes but maybe these are the cheap original bulbs which were replaced with philips bulbs. I am now considering replacing the office downlights with 12v versions and as the hallway is so seldom used, its probably not worth changing.

One thing I did note, always use covered globes in the kitchen as the globe doesn't last long with steam and smoke from the "smokeless grill" affecting the quartz glass.

[wonnie]

just becuase this thread isnt long enough, here is another angle.

has anyone replaced their halogens with LEDs. I noticed Jaycar has 20LED units but im am not sure on how well they would replace a 35 or 50 watt halagen?

[John99]

Well what a thread !


I`m new to these forums and amazed at the topic, down lights, and the passion it brings out

my 5 cents worth,invent LED down lights that work and save the greenhouse effect !


cheers !
John99

[Captain Caveman]

Cassandra (Hope I am not too late!)

I read a magazine called 'Renew' which is always promoting new eco products for the home and garden. In the December edition they had a Compact Fluorescent replacement for Halogen downlights which I bought a couple of.

They truely are remarkable and fit into existing Halogen holes. They use 1/8 of the energy (9 Watts) and give off very little heat compared to the halogen units. They are also meant to last 15000 hours (will have to confirm this in about 8 years!) and run with no transformer because they run off direct 240V.

The supplier has a calculator on their website so you can see how much money you are saving if you use them to replace halogens in your home.... it's pretty scarey stuff! I have sixty of the buggers in our house which aparently use $800 a year in energy. So I am planning on changing all of them when I can afford it.

I too tried LED's and found them to be more of a hobbyists toy and were unpractical with a disappointing light - I reckon the technology will be there in a few years tho.

The supplier of the Fluro downlights is Neco www.neco.com.au (http://www.neco.com.au) phone 1300 88 26 40.

[sparkynsw]

TRANSFORMER HUM

As an electrician of ten+ years i have found that conventional iron core transformers hum and intermittently overhead in some cases due to the use of cheap globes.

i have had problems with sylvania globes (around $3.00ea) before causing overheating and humming and as a result now steer clear.

As callbacks are costly and time consuming i only use quality atco transformers matched with a colour corrected GEC globe (around $15.00ea) since using this combination (5yrs) i have not had a single callback.

It may also interest you to know that the light output of these globes is significantly brighter and a 35W globe is usually as bright as a generic 50W halogen globe.

before replacing your transformers try using a better quality globe......

[Gumby]

Thanks Sparky. Mine have been in for a while now and I haven't had any probs. I'll upgrade the globes as they go.

[Iain]

Not disputing your comments sparky but how does a non mechanical device cause problems with a tranny?

[wonnie]

Cassandra (Hope I am not too late!)

I read a magazine called 'Renew' which is always promoting new eco products for the home and garden. In the December edition they had a Compact Fluorescent replacement for Halogen downlights which I bought a couple of.

......


The supplier of the Fluro downlights is Neco www.neco.com.au (http://www.neco.com.au) phone 1300 88 26 40.

Thanks for that captain, i going to order 5 now to replace my current kitchen stock, the heat savings alone should be worth it

[jimc]

I too can vouch for these 9w flouro replacements from Neco. I ordered two warm white versions and am very happy with the result. The light is not instant but starts faster that BNC compact flouros.

One bulb was broken in transit, however Neco sent a replacement immeadiately.
The result....one very happy customer

[SOLOCHICK]

Since this is such a huge post and so many of you know about Downlighting, SOLOCHICK needs your advice.

I just had downlights installed throughout my home. Love the look but but are waaaay too bright. Got the sparky to put a dimmer in the kitchen but in the toilets, hall and bathroom I didn't do.

I'm find the light too white? if that makes sense?
got the globe packets out of the bin and they are 50W cool beam.

Is there other types of globes I can get? something with a bit of a warmer light? It just seems all a bit too football field lighting for me now and so disappointed with my investment.

Any suggestions?

[soundman]

Firts option is 20 watt lamps.
Allmost alll dichroic fittings will take a 20 watt lamp. Are they the low voltage type? if yess no problem.
As far a colour, unless you want COLOUR they only come one way.
cheers

[Ashore]

Put a new kitchen in 8 yrs ago 6 downlights in ceeling and 3 under benchtops
benchtop ones are 19mm thick with transformers on top of cupboard Have only blown 3 of ceiling lamps in 8 yrs
Only traps I found by asking around were
Good venterlation around transformers (two story homes appear to suffer with down lights on lower floor) and mount them verticle from the bottom
Always use sealed lamps ie with cover over lens the open ones are cheeper but dont last
Dont fit them too high "Cathederal celings as in the better fittings you need to un screw them with screwdriver if you can't get at them from above can be un-nerving 20 foot up on top of a ladder"
Buy good quality




He who dies with the most toys is nonetheless dead.

[doug1]

Cassandra you can get very small compact flouresant lammpsto suit down light fittings standard lamps (ES, BC ,SBC, candle etc) these dont have the heat load of halogen but give the light output,these lamps I have only seen at specialist lighting shops to date. They are very small. Also the small flouro lamps (8W, 13W) may also be better for cupboard use than a spot light.

[kiwigeo]

We found in hot weather the transformers would switch-off with the heat overload cutoff and take 15 minutes to cool down and come back on..... again the newer more expensive models are more stable.



If a halogen is flicking off during hot weather it pays to check that there isnt ceiling insulation lying over the transformer...had two halogens in my dining room doing just this. Moved insulation clear of the transformers and the problem was solved.

Agree with you on the stability of the more expensive models...

[Metung]

Another quirk of 12v downlights - I had some 240v halogens that were hopless and replaced them with 12v, electronic transformer ones, 2 globes off each transformer. The rest of the house has 12v, ironcore transformer, downlights. Anyway SWMBO turned the telly on and complained about snowy reception. Turned the new lights off and the problem diapeared. "##!!" I thought to myself, I'm going to have to replace them again. The channel was changed from 2 to one of the commercial channels later on and there was no problem. Checked all the other channels and they were OK too. SWMBO said that she could put up with the interference on 2 so I'm off the hook and I wouldn't trade her in for quids.

[Iain]

Metung, before you give up here are three options so you can receive ABC 2.
#1. Get a digital set top box.
#2. Replace what is probably crap coax with RG6 Quad shield including flylead from wall to TV.
#3. Get a flylead with a ferrite sleeve either end.
Work from #3 to #1 as this is the cheapest order.
ABC digital is Channel 6 and employs a completely different technology to analogue TV, you cannot get interference.
50Hz radiation is a common problem with low end TV reception, we had the same problem with 3 phase radiation and went digital to overcome the problem.
Feel sorry for the poor buggers in Mt Gambier who still have channel 0.

[soundman]

If you are getting interfeerance on channel 2 it is likely to be comming from a swithmode (electronic) transformer. Particularly if it looks more like rain than snow ( big dots regular pattern).
Change to old style iron core transformers should solve the problem.
Saw this sort of thing a couple of times when I was in the antenna business. Actual 50Hz wont touch ch2 or any other TV reception there has to be some other nastyness involved, like a switchmode supply, arcing contact or similar.
Yess ch2 is more prone to 50Hz "related" nasties. Chase the nasties.

cheers

[hogradys]

Hi everyone,
Love your forum. I have 8 downlights installed in a combined lounge/dining/ kitchen with 12ft ceilings. I built the place 10 years ago and my first downlight has failed. I thought it would be simple to change but no. The lights are flush with the ceiling (ie no raised areas to twist). The 3 kitchen lights have had their protective glass broken but the lounge lights remain covered. All have separate transformers and no dimmers. I recently installed insulation in the roof and have left room around the transformers and lights for ventilation.
I cannot work out how to change the lamp. The housing containing the bulb appears to be bigger than the circular rim. I can push the bulb housing up (appears to be spring loaded). The existing bulb is a 12V/50W/36deg. I can't twist anything as there are no "grip" areas. Sorry for not knowing the terminology. Please help as I'm thinking of clling a sparky and geting them all ripped out after reading some of the posts on this thread.
Regards,
Ho
:)

[Master Splinter]

Trivia time for downlight people...

That buzzing sound you hear from transformers is magnetostriction - the slight change in length of the iron laminations as they become magnetised. It's a 100Hz hum.

At least wood doesn't change size that quickly.

[baltic]

Hi all,
what a big thread, got lots of ideas and took on board lots of advise. I would like to share with you my lights that I installed with the help of a qualified sparky,
I decided to use down lights on a trapeze line, three runs, a total of 24 lights, that lights a 55 square meter area. I think they work well, all fitted with dimmers. Each trapeze is juiced up with a 400 watt transformer.

I also installed quality "stainless steel up lights", and yes they have expensive $25/LED glob lights in them, so as not to burn your toes!!
I hope that it will not be a full time job changing bulbs!!

Cheers,
Gary.