LED Light Bulbs & Light Fittings - Advice & Tips
With the price of LED light bulbs, LED downlights and all things LED dropping so markedly in the last 18 months or so a large proportion of questions
I'm asked as an electrician has to do with people wanting advice on changing over to LED lighting in and around their home.
The most obvious advantage of LED versus the old style incandescent lights is the big savings in energy usage with LEDs. Before I go into how the two types compare it would pay to cover the basic terms that are used to categorise LED light bulbs themselves.
Wattage - this is simply the rating of how much power the globe consumes in Watts.
Lumens - lumens is the measure of light output of the globe, the higher its lumens rating, the more light it outputs. Comparing the wattage of an LED light bulb with its lumens output also gives you an indication of how efficient the globe is. A low wattage rating coupled with a higher lumens output means the globe is more efficient at converting the power it consumes to light.
Beam Angle - the beam angle indicates the spread of light from the globe itself. A narrower angle will give more of a spotlight whereas a wider angle will cast the light across a wider area. It's quite important to take note of this when deciding what type of light, particularly LED downlights, to use in a given situation. You would want a narrower angled light to light workspaces ie. kitchen benches, laundry sinks etc. but a broader beam light would be more suitable for living/lounge rooms and bedrooms.
Light Colour - LED light bulbs are rated with a degrees Kelvin figure, the lower numbers will be a warmer, softer light, a higher figure indicates a brighter, whiter light as you move across the spectrum towards daylight. Like the beam angle the light colour is also important to note when deciding what situation the LED will be used for. Softer warmer colours are good for lounge rooms and bedrooms, whiter, brighter globes for kitchens and work areas.
Changing over to LED downlights
One of the easiest way to upgrade to LED lights, particularly in downlights, is to simply replace your halogen bulb with a comparable LED light bulb. It's
not always that simple though, older style iron core transformer downlights often won't drive LED globes. Newer electronic transformers often will but not
always either. Adding to the uncertainty is that various LED globes themselves also may only work in certain downlights.
The best way is to purchase one LED globe and test it across all of your downlights, if it works then you can outlay the cash to replace them all.
The physical size of the LED light bulb can sometimes be a problem as well. If you're going to retrofit some GU 10 LED globes into a light bar style fitting you may find that the LED globes will be longer than the original halogen globes. This is often the case when a light fitting runs at main voltage (meaning there isn't an external transformer to step the voltage down and convert it to DC that the globe runs on) so the LED globe that suits that fitting has the associated AC to DC circuitry in the base of the globe itself. This makes the globe physically bigger and for heat dissipation the globe will often have a heatsink built into it as well.
The following is a comparison chart so you can see equivalent ratings between incandescent and LED lights. We haven't touched on compact fluorescent lights (CFL) in this article but I've included them in the chart as they are very common in households now.
|Incandescent Watts||CFL Watts||LED Watts||Lumens (Brightness)|
The old adage, you get what you pay for, also applies to LED light bulbs. There are so many different globes on the market now and many of them are cheaply made. The globe you got on sale at ALDI may have been $12 cheaper than the Phillips globe but when it fails after 30 hours instead of the advertised 30, 000 hours you'll be way behind. Let the buyer beware.
Dimming LED Lights
Some LED lights are dimmable and some aren't so check the product documentation to be sure however you may be a little disappointed with how well they
dim when you take them home and plug them in. They may flicker or only have a narrow range from fully dimmed to fully on. That's because most of the
dimmers we have fitted in our homes are what's known as a leading edge dimmer. They dim the light by modifying the AC sine wave and are designed to work
with higher resistance loads such as incandescent and halogen globes. They will have a minimum load requirement (usually starting somewhere around 25
watts) before they will start to work so you may find that if you have a dimmer for a single light and you replace that light with an LED light bulb the
new bulb won't be enough of a load for the dimmer to work at all.
That's not always the case though and often LED dimmable globes will work with leading edge dimmers. I have a single 13w LED globe connected to a leading edge dimmer in my dining room and it works, and dims, reasonably well. You will sometimes get a buzzing sound from leading edge dimmers due to the way they work.
The second type of dimmer is called a trailing edge dimmer and they will work with electronic LED drivers and transformers. This is the recommended dimmer type for LED lights and will give a smooth consistent control when you're dimming the light.
Thirdly there are universal dimmers which will work with all types of lights, LED and incandescent/halogen. They are a bit more expensive than the other two types but, as I just mentioned, have the advantage of compatibility with all types of lights. I use and recommend the Clipsal universal dimmer to my customers.
As the cost of LED globes has dropped so also has the price of complete LED downlights, feature lights and various other LED fittings. Keep in mind that if you are considering retrofitting a number of downlights for example it may be worth having the fittings themselves changed over completely, this ensures that everything works properly and avoids the uncertainty about which globe works in which fitting, transformer type etc. This can save a lot of hassle and if you're just doing a straight swap from one type of light to another the cost of the job may be cheaper than you think given that the associated circuit wiring and switches are already in place.
If you have any specific enquiries regarding LED lighting or need some advice on changing over lights in your home then please contact us at FRC Web & Electrical and we'll do our best to help.