Energy efficient lighting and quality of light

Energy wasting incandescent.
Turn it off to save the planet!

If you have not already started to feel guilty about the lighting in your house, someone is going to make you feel that way soon! There is a huge, and well founded, move towards encouraging us to make the lighting in our homes more efficient. After all – if we can create the same amount of light for 20% of the energy and the bulbs last five times as long then we should just do it, shouldn’t we?

Well, yes and no. There’s no question that you can save resources and energy by using the new technologies now available in lighting and this article will discuss each of these in some detail. However, these new technologies use quite different methods to create light more efficiently than the old incandescent bulb that we’re used to.

The differences in the QUALITY of light that you get from each technology mean that it is quite possible to end up creating the same amount of light that you did before but with your house looking bland, cold and inhospitable rather than warm and cosy.


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So, the key is to understand how to:

  1. Lower your power usage for lighting
  2. Use globes or bulbs that last for much longer
  3. Maintain or, ideally, improve the decorative and functional effects of light in your house
  4. Do this within a reasonable budget

This is a huge subject as you can imagine. You will find lots of scientific and technical descriptions online and if you’re really keen to understand these one of the better places to start is on Wikipedia. However, in the general style of our website, here is a general guide that most people will understand quickly.

Space saver compact flourescent.

The “standard” home

We’re going to assume, since you’re looking at this site and clearly care about your home, that your current lighting doesn’t look too bad.

The “standard” builders solution for lighting a new home (and it has been this way for at least 10 years) is to use normal incandescent fittings or banks of halogen downlights in the ceiling to provide the ambient (general) light that you might want in a room and leave it to you to add some atmosphere with table lamps where you need them.

They will often put a fluorescent tube light in the kitchen and in some cases put them in bathrooms as well. If not they will use halogens again in these places. They will almost always put fluorescent tubes in the garage and will either use incandescent, high-wattage halogen or fluorescent lamps outside.

If this pretty much sums up your home, you wouldn’t be alone. Whilst you may have an extra couple of halogen sconces and some specific halogen downlights pointed at particular artworks, most of our houses are like this.

So, how do you lower power consumption without making your house look like a loading dock?

The problem with just replacing all of your existing incandescent bulbs with compact fluorescent bulbs (which is what the government is encouraging you to do) is that many colours, particularly reds and browns, will appear dull and washed out in their light. Incandescent lights provide warmth in their light that even “warm white” fluorescent lights cannot replicate. However there are some immediate things you can do that can reduce your consumption considerably.

Install dimmer switches on banks of ambient halogen downlights that are left on for any length of time. Dimmer switches aren’t cheap. It will cost about $100 to have an electrician install one for a bank of lights. However, you probably only have a couple of rooms like your living and family rooms (and probably your kitchen) where this would make sense. Dimmers enable you to only use the amount of ambient light you really need rather than flooding the room with light. They also allow you to create different effects very easily.

Progressively replace all of your 50W halogen downlight bulbs with 35W bulbs that give the same light as the 50W bulbs. Other than cost (the bulbs are slightly more expensive than cheap 50W bulbs) there is no excuse for not doing this.

Use “task lighting” like reading lamps where and when you need them. They don’t need to be on all of the time. Use “effect lighting” like table lamps or perhaps even some LEDs to give the light pooling and effects that give a room character. LEDs burn very little power and are great for providing effects but are still expensive and are a long way away from providing decent ambient light at a reasonable price.

Replace incandescent bulbs with compact fluorescent bulbs in all service areas EXCEPT those where the light are only turned on for short periods of time or the full brightness is needed immediately. Compact fluorescents are not efficient if they are turned on and off for short periods of time.

Don’t use higher wattage bulbs than you need for the incandescent lamps you are using for general light in bedrooms and other rooms.

You should try a good warm white compact fluorescent bulb and try it in each of your table tamps and other task lights. If you can live with the colour rendition it gives from a light, great – use it in that situation, otherwise just install an appropriate long-life incandescent bulb. Warm white compact fluorescent lamps can look good when they are lighting predominantly white items (particularly white furniture) and can be very suitable for a reading task light. They are particularly poor at replacing bulbs in table lamps which are providing pooled light around wood and colourful items.

This solution alone will save between 35-60% of the power you use on lighting and using the dimmers on your banks of halogen lamps will allow you to create more lighting effects within your house without compromising the light quality.

   
Compact flourescent bulb disguised as an incandescent bulb

Experiment!!

Lighting quality is very important in a house. A home should be a gentle, welcoming place at night and light quality more suited to a garage forecourt needs to be ushered in carefully. We strongly urge you to experiment with a couple of compact fluorescent bulbs first rather than buying loads of them, installing them and then throwing them out a few weeks later when you realize that you don’t like their light.

We do tend to overlight rooms since our love affair with low voltage halogens began. Think about other lighting schemes for your home that use less light and turn off lights in unused rooms. The accompanying article on lighting in the home explains effects in more detail.

Some guidelines and thoughts

  1. Incandescent bulbs (normal bulbs and halogen downlights) give the warm, comfortable colours that your eye perceives as being a good substitute for daylight. In technical terms their “Colour Rendition Index” or CRI is 100%. ANY other light, even if it calls itself, “warm white”, or “daylight” will give you a different perception of many colours. Flesh colours, neutrals and reds look very different under fluorescent light. As a result, if you’re going to change these bulbs think about the purpose of the light you’ll be moving to and whether the alternative light will kill atmosphere.
  2. There is a common fallacy that low voltage halogen downlights consume less power. This is not so. A 50W low voltage halogen bulb burns 50W just as a 60W incandescent burns 60W. A bank of 6 50W halogen bulbs (very common in lounge and family rooms nowadays) burns 300W. Changing to 35W bulbs (giving the same light) and dimming to 60% would mean that the same bank of bulbs are now burning just over 125W. Quite an improvement and it would look good too.
  3. Fluorescent and compact fluorescent lamps are only truly efficient when they are left on for more than a few minutes. If you only need light for a short period then they won’t save you much money. Many fluorescent bulbs also take a few minutes to come up to full intensity and if you want immediate light you’ll be frustrated.
  4. LED lights show great promise for the future but they are very expensive at the moment and there are no bulbs currently on the market that functionally take the place of incandescent or halogen bulbs for ambient light at a reasonable price. However, for effect lighting they can be quite spectacular. They burn very little power and have an extremely long life. It is likely that LEDs will form a major part of our lighting solutions for the future.

DO

  1. Fit dimmers to all incandescent and halogen lamps in living areas. You’ll find that a lot of the time you only need a fraction of the total lighting capability to give you the light that you need.
  2. Use the latest efficient bulbs for halogens. Some manufacturers such as GE manufacture 35W halogen bulbs that produce as much light as 50W bulbs. This immediately saves 30% off your power and gives you the same quality of light.
  3. Use fluorescent lamps in your garage or carport (use warm white lamps unless you want the effect of colder lamps for a specific purpose).
  4. Get rid of ALL high-wattage halogen lamps. There is almost no situation in a normal home where you need 500W, 300W or 150W halogen bulbs, but they are commonly installed in yard lighting and in halogen sconce lights. A 24W compact fluorescent bulb in a good yard lamp will give a lot of light when it is needed.
  5. Use warm-white compact fluorescent fittings where they will not be lighting wood or other materials that naturally have a red or brown hue to them. They are great for reading or next to white walls and white furniture.
  6. Look for opportunities to use LEDs. At the moment they are still expensive, but LED strip lights hidden behind pelments can provide wonderful effects and a reasonable low wash of light when not much light is required. They are very energy efficient.

DON’T:

  1. Overlight your rooms. Have additional light available for when you need it, but don’t use it all of the time.
  2. Do nothing. Using a combination of better lighting strategy, more efficient and longer lasting incandescents, dimmers, compact fluorescents and LEDs you can substantially reduce your lighting bill and create less waste. Remember, many cheap bulbs are not as efficient for light and burn out quickly. Check the expected life.
  3. Rush in to wholescale replacement of your incandescent bulbs with compact fluorescents. You’ll just end up throwing many of them away.
  4. Use fluorescent bulbs where the lights get turned on and off for short periods of time.
  5. Leave high-wattage lamps on. If you want lights on around your house for effect then make them as low energy as possible either with dimmers, low wattage bulbs or by using LEDs.
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