Halogen downlight advice needed

[Aloysius]

Can I ask for some advice on the recessed halogen downlights we are fitting for our lounge (around 12 x 12 feet)?

We were initially advised that we needed to 9 or 11 lights so I have bought 11 low voltage fittings with an MR16 50W bulb in each. I now think this is far too much - both in terms of the sheer amount of light required and in terms of cost (bills, bulbs, and cost of special dimmer required for this total wattage).

Would I be better with fewer lights - perhaps just 5 or 6? Is there anything particular to bear in mind?

I'm also confused whether I need to double the total wattage for these lights in choosing a dimmer capacity or whether this only applies to mains voltage halogen.

Lastly, should I also be getting fire hoods for these fittings?

 

[Steve]

Is it too late to take them back? Halogen downlights do one thing very badly: Lighting up a room.

The things they do well:

*Setting fire to insulation, joists, ceilings and floors above.
*underfloor heating for the rooms above.
*giving you very high energy bills.
*boiling your forehead when stood under them.

Think about what you've done. You started out with a light fitting with, say, 3x40w lamps. 120w. You have had to replace this with 550 watts of halogen lighting to get a decent light level. Thats nearly FIVE TIMES the wattage! Even if you dim them to 50%, they will still use probably 70% of their power (dimmers dont work proportionally)! Halogens dont like being dimmed, they dont work very well and wont last as long (wont bore you with details).

If you want to use these fittings you have bought, I suggest you try LED lamps. Go for the expensive ones (£20+) with three high power LEDs. The ones with 20+ LEDs are cack and cheap. Remember when you buy them that you may never have to replace them.

LEDs run cooler and use 1/10 of the energy. BUT you cant dim them.

 

[ericmark]

Quartz Halogen lamps should not be dimmed as it will shorten their life.
MR16 are not normally low voltage these are normally extra low voltage.
The MR16 has a problem as wrong lamps can be fitted. There are many different wattages, angles, and reflectors some which reflect heat and some don't.

Low voltage lamps normally use GZ10 or GU10 these are designed so GZ10 lamps which don't reflect heat with not fit in GU10 holders but GU10 lamps will fit in GZ10 holders so they are safer as to fire caused by heat. Also you have options of using both Cold cathode (Florescent) and LED lamps with low voltage but only LED can be used with extra low voltage.

Because the inverter used with extra low voltage give a more controlled voltage to the lamps they give sightly more light per watt and last longer however fitting any dimmer would completely mess that up.

The norm is to install the lamps as 1/3 and 2/3 of units on each switch giving three levels of lighting but really 50mm is to small and 300mm diameter is really required to get the spread of light required.

The 50mm spots are designed to light pictures and other items of that type and are not for general lighting. To fit these type of lamps when tungsten lamps are being withdrawn seems a little short sighted and I would advise if you like the general shape then go for low voltage so energy saving cold cathode lamps can be used in same fitting.

Note:- up to 50vac is extra low voltage.
From 50vac to 1000vac is low voltage.
So 230vac is Low voltage.

 

[electronicsuk]

Can I ask for some advice on the recessed halogen downlights we are fitting for our lounge (around 12 x 12 feet)?

We were initially advised that we needed to 9 or 11 lights so I have bought 11 low voltage fittings with an MR16 50W bulb in each. I now think this is far too much - both in terms of the sheer amount of light required and in terms of cost (bills, bulbs, and cost of special dimmer required for this total wattage).

Would I be better with fewer lights - perhaps just 5 or 6? Is there anything particular to bear in mind?

The problem with downlights is that they usually have quite a tight beam angle, so with as few as five or six fittings, you'll probably find the room is not lit evenly.

If you replace the stock lamps included with the fittings, it may be perfectly possible to effectively light the room with as few as six fittings. I would suggest these as a suitable alternative:

50w 12v MR16 60deg coolfit lamps

These lamps have a fairly wide beam angle, and an aluminised reflector, which will reflect the heat from the lamps back down into the room, and help negate any issues with heat rising into the space above the ceiling.

For some unknown reason, dichroic lamps are usually supplied with these lights, which kick most of the heat back up into the ceiling. That would be fine if you were lighting something like a picture, but the manufacturer's must realise that this is generally NOT how the products they're selling are being used. This coupled with shoddy installation work can lead to a fire risk, but I think it's very unfair for Steve to imply that all MR16 recessed lighting suffers from this problem.

You may find that a couple of the forum regulars will try and dissuade you from installing this type of lighting. However, they often do not appreciate that, for some people, aesthetics are consideration of equal importance to energy efficiency. You should feel free to make your own, informed decision on what is best for you.

I'm also confused whether I need to double the total wattage for these lights in choosing a dimmer capacity or whether this only applies to mains voltage halogen.

You'd need to consult the instructions for both the dimmer and the transformers. I'd advise against putting everything on one dimmer, assuming that the transformers are capable of being connected to a dimmer at all.

Lastly, should I also be getting fire hoods for these fittings?

Is the ceiling a fire barrier?

 

[riveralt]

Can I ask for some advice on the recessed halogen downlights we are fitting for our lounge (around 12 x 12 feet)?

We were initially advised that we needed to 9 or 11 lights so I have bought 11 low voltage fittings with an MR16 50W bulb in each. I now think this is far too much - both in terms of the sheer amount of light required and in terms of cost (bills, bulbs, and cost of special dimmer required for this total wattage).

Would I be better with fewer lights - perhaps just 5 or 6? Is there anything particular to bear in mind?

You may find that a couple of the forum regulars will try and dissuade you from installing this type of lighting. However, they often do not appreciate that, for some people, aesthetics are consideration of equal importance to energy efficiency. You should feel free to make your own, informed decision on what is best for you.?

Not quite a forum regular, but to help you make that informed decision, perhaps you should read the following report on the Electrical Safety Council

http://www.esc.org.uk/business-and-community/research/luminaires.htmlwebsite - its not all about energy efficiency...

 

[ericmark]

Somehow the word website has been attached to link http://www.esc.org.uk/business-and-community/research/luminaires.html is correct link address.

The way the tungsten quartz lamps work is the quartz is that hot the tungsten can be deposited on the quartz and instead gets re-deposited back onto the tungsten allowing the tungsten to be hotter then in a glass lamp.

Running the lamp cool will reduce it's life considerable however there are situations like where films are shown where it is required to turn the lamps down and as a result inverters are made that can be dimmed. These monitor the leading or trailing edge of the wave form and have to be same as dimmer.

LED and discharge lamps can be dimmed but again the control needs to match the lamp. With discharge often one has to flick the switch to control dimming rather than have special dimmer control.

The switch on current of the tungsten quartz lamp is far higher than the tungsten glass lamp and also they often have ionisation as they blow so the dimmer needs to be higher rated and also fused the MCB is too slow. Unless fuses are included often lamps blowing will take the dimmer switch out when they go. Some inverters offer some protection but it has been noted often when lamps blow they also take the inverters out as well.

OK they look nice but as extras they are OK but as prime lighting they can plunge one into darkness all too easy and there use is very limited in my home. They are fitted behind bed as reading lamps and one is still a tungsten quartz lamp which since they get so hot is not really a good idea the other has a cold cathode lamp fitted.

 

[ban-all-sheds]

Can I ask for some advice on the recessed halogen downlights we are fitting for our lounge (around 12 x 12 feet)?

In a nutshell:

Don't.

Simples.

 

[Steve]

Can I ask for some advice on the recessed halogen downlights we are fitting for our lounge (around 12 x 12 feet)?

In a nutshell:

Don't.

Simples.