Low energy light bulbs are a great way to save electricity but
as you can see below as well as advantages there are a number of potential disadvantages to take
into account before deciding to use them. The comments below apply to CFL replacement low energy bulbs which are just becoming available at sensible prices.
| Disadvantages |
|
|
| High cost |
- |
Vary between just under £0.50 and £9 - these costs are falling all the time |
| Can be heavy |
- |
Put a higher strain on cable and termination when fitting
suspended by cable. |
| Can be larger than a standard bulb |
- |
May not fit some light fittings although a larger variety
of fittings and smaller bulbs are rapidly becoming available. In particular GU10 type replacements may not fit all types of fitting. |
| Less tolerant of frequent switching |
- |
Frequent switching shortens the life, manufacturer's figures
are for ideal conditions |
| Take time to reach full output |
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Approximately 30 seconds to reach full intensity - can
be disconcerting |
| Light colour not the same a standard bulbs |
- |
Depends on your preferences but they are different tending to be whiter. The newer types are much better in this respect. |
| Confusing variety of types and costs |
- |
Be cautious the cheaper ones typically have a shorter
life and can have a lower output in lumens per watt. |
| Manufacturers inconsistent with economy ratings |
- |
Some manufacturers rate them as 'A' others as 'B' on the
energy efficiency scale |
| Incompatible with dimmer switches |
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This is now only partially true since bulbs are becoming available that can be dimmed, however they are expensive. |
| Light output drops with time |
- |
It is slow but noticeable when comparing old & new
bulbs of same wattage |
| Don't like being operated on their side? |
- |
Appear to have a higher failure rate operated horizontally
also poor connections sometimes especially with cheap fittings |
| Not all bulb types available |
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Mainly bayonet, screw and GU10 at present but the range is increasing all the time. |
Can flicker occasionally when switched off |
- |
When fed from very long cable runs (e.g. lights switched
from the top and bottom of stairs) the capacitive coupling
across the cables can cause the lights to flicker occasionally
when switched off. This is quite rare. |
Contain a small amount of mercury |
- |
Modern designs contain only a very small amount but it does vary by manufacturer. Provided the bulbs are disposed of properly this isn't an issue. |