Information - Halogen FAQ's

Low voltage Halogen – VS – Mains Voltage Halogen

What is the difference?

Low voltage or ‘dichroic’ halogen lamps need to operate through a 240v to 12v transformer. As a result the LV lamps are more efficient than the mains voltage type. When lit the lamps do look very similar, however, there are some differences.

Do the two lamps give the same light output?

No. A 50w mains voltage halogen lamp gives approximately 50% less light than it’s low voltage equivalent. This is fine if you just want a soft glow from your downlighters, however, if you have a high ceiling or you want a ‘punch’ of light then only a low voltage halogen lamp will provide this. In addition, the low voltage halogen lights will give a much sharper, whiter light.

Won’t adding a transformer to each light make it more expensive?

Having a transformer will add to the cost of the lighting system. However, you will be getting twice the amount of light. All our transformers can be dimmed using a standard domestic ‘resistive’ type dimmer. Also, if you installed a 50w LV halogen lamp but found it too bright then our transformers will run a 35w or 20w version.

Do the two lamps come in different beam spreads?

Yes. The mains voltage lamp is available in a 25 and 50-degree version. The LV lamps come in 10, 24, 38 and 60-degree versions. These will give greater flexibility if you wish to light a painting or frame an object.

How long do the bulbs last?

The average life of both lamps is around 2,500 to 3,000 hours.

Do both lamps give out a similar amount of heat?

Yes they do but in a completely different way. Firstly, all 50w halogen lamps operate at around 85c. That’s pretty hot! The mains voltage lamp actually projects most of this heat forward. This is great if you wish to fit them in a narrow ceiling void but not so good if you have a very low ceiling. The LV lamps on the other hand direct the heat backwards but are very cool at the front.

If I use low voltage lights could the heat from the lamp affect the transformer?

This can happen. From experience we find that most problems related to low voltage lights exist due to unsuitable location. Because of this we recommend downlighters should not be fitted into a ceiling depth less than 6 inches. Also, the transformer must not be sited immediately next to the fitting. In addition, any insulating material should be well clear of both the lamp and the transformer. If you follow these guidelines then the majority of potential problems can be avoided.