[cadesmarais]

Hi.

I am renovating the kitchen and plan to install small halogen MR16 ceiling pot lights. Contrast and Lightolier have been recommended. At least, the Contrast line is available with either line or low voltage feeds.

These questions come up as the plan calls for 9x35w MR16 (ceiling pot lights) and 4x20w MR16 (puck lights).

1. What are any trade-offs going with line voltage MR16s? These are generally simpler and eliminate step down transformers, which tend to drive costs higher and I have read do have somewhat higher failure rates.

2. Knowing that halogens run much hotter than say PAR20 bulbs (I believe because of the halogen's much more compact bulb size) is there any difference in the heat generated by halogens at 120v or 12v. I don't believe so, as a watt is a watt, save maybe for the negligible power used by the stepdown transformer.

3. Other than a neater appearance and less pin-point focusing ability (gimbals, etc), larger PAR 20s will outlast equivalent halogens, requiring less frequent replacement. I know of this as I have PAR20s form a mid-eighties reno and have seldom had to replace the 50-75w bulbs. Have I got this right?

Thanks in advance.

... André (cadesmarais)

[KISS]

1. Higher failure rates because the filament is more fragile. Vibration is bad for the higher voltage.

2. True statement

3. Can't really answer.

4. Halogens have a shorter life when dimmed. Transfomers make dimmers more expensive.

[tkrussell]

Choosing lighting can be a daunting task.

Generally, halogens (MR16) have a longer rated life than standard incandescent lamps.

You mention PAR20, are you sure this is not a halogen also?

A halogen is an incandescent lamp on steroids. The filament is much more compact, creating a much smaller point source that creates more lumens (light output) in a smaller bulb.

Halogens last longer due to the characteristic of the gases inside, as the tungsten filament, same as used in a standard lamp, evaporates, the tungsten re-deposits back at it's source, giving the lamp longer life.

Dimming a halogen defeats the action of re-depositing the filament, and reduces operating life. For residential use, this reduced life may not be so noticeable. It will be a compromise, whiter light that can be dimmed, or change lamps sooner.

The smaller filament that does not evaporate quickly burns hotter, giving a much brighter light operating at a higher color temperature, or whiter light.

A standard incandescent lamp will provide 2700 Deg kelvin color temperature, and a halogen will be closer to 3000 Deg K, which will be whiter than the incandescent.

Note, "color temperature" is not the operating temperature, the heat you can feel.

So, halogens burn hotter in both heat and color temperature.


Halogen lamp - Wikipedia, the free encyclopedia


R20 lamp Standard incandescent
47682 - Features & Photos - GE Home Lighting Products

PAR20-Halogen Lamp

14928 - Features & Photos - GE Home Lighting Products


Any halogen fixture must be installed as rated, with concerns of the additional heat that will be created.

A lamp is chosen for several factors. If a halogen is used, you must be ready for the whiter light output than a standard incandescent. Sometimes this is not noticed, sometimes a halogen gives more whiter light than an incandescent, and is not what the desired effect is, let's call this "atmosphere", or a warmer ambiance.

Whiter light can feel or seem colder that incandescent light.

Next comes the distribution of light. A PAR lamp will be slightly different that a R lamp. Most not noticeable to a layperson. A PAR will be more controlled light, and a R lamp will be more general or scattered.

These types of lamps help with distribution, and do not rely on a fixture to "push" the light. The puck lights use a different lamp that needs a fixture's reflector to "push" the light, for example.

So, I am not sure if I helped you any with my ramblings. I will stop here, as I can go on forever with lighting.

If I helped, great, if not get back with any other questions and details.

Be sure the recess cans are rated for the application. If there is insulation in the ceiling, use IC ( In contact) rated housings. If no insulation, either IC or non IC rated can be used.

[cadesmarais]

My thanks to TKRUSSEL and KEEP IT SIMPLE STUPID for your thoughts and tips.

This is a late follow-up to acknowledge, but I much appreciated your input.

I finally went for 12 v MR16 recessed halogens and some Xenon fixtures for the under counter.

I may have confused you in my questions, as my terminology was not as specific as it should have been.

The best lighting from halogens comes from:

1. Quality 12v. MR16 bulbs (uniform very white light, some with high life up to 7 K hours)
2. Followed by 110 V. GU10s (spotty lighting pattern, short life span as there does not seem to be different quality products in this line)
3. follwed by PARs (standard socket type bulbs with a halogen core, again with spotty lighting patterns, bulkier enclosures and short life spans).

Xenons were chosen as they are 'cold' compared to halogens and in under counter installations heat can be an issue.

A demo of these three options is the only way I found to really 'see' the difference.

Cost is definitely an issue as quality MR16s fixtures (made in US - Lightolier or in Canada - Contraste) will run 2 to 3 times the others that are all mostly from China.

No surprise, you pay for what you get - quality!

Best regards,. André

André Desmarais
e-mail: [email protected]

[KISS]

Thanks for the follow-up.

[beachhouse]

Need to replace floor sliding dimmer for halogin 50w lamp 120v to 12v I/p 120v--o/p 12v Mfg Jing Neng Tech model e233591