A
Arny Krueger
- Jan 1, 1970
- 0
Phil Allison said:
The variations in dimmable CFLs are pretty obvious in use. The effective
range of operation, and how they react to being run at low levels, can varie
quite a bit. We see both sample variations within a certain type of bulb,
and also brand and model variations.
Keeping a dimmable CFL running at low levels is a bit of black art, it
seems.
Dimmable CFLs are available in the US from places like "Home Depot" - the
US's large chain of home improvment centers with over 400 superstores
nationally.
Dimmable CFLs are also available from a number of dealers on the web, and
regular local electrical supply stores that cater to electricians. Prices
there are in the range of $6-18 per bulb.
Really good dimmable CFLs in the 15-22 watt range are presently being
blasted out on US eBay for about $4 each.
I am reflecting on my experience which is based on the use of several 100's
of bulbs in a church/school. For example, we have one room with 48 CFLs, and
another with 64. Many other rooms have 6-12 bulbs each.
The room with 64 bulbs has been in service for about 3 years and gets pretty
heavy use by household standards. Its a basement room with zero windows, so
it has to be lit every time it is used. The lights are often left on until
the end of work day even when it is vacant.
The 64 32 watt bulbs in that room are used in pairs in a fully-enclosed ca.
1950 ceiling fixture that has has a maximum rating of 150 watts. They run a
little hot but have been very reliable, anyway. I think there have been 2
bulb failures in 3 years. Light levels are a real problem in this room, so
the purpose of rebulbing was to get enough light, not save power. We got
both benefits, anyway. It was previously lit by 32 150 watt halogens. They
ran very hot and one died about every week.
The 48 CFLs in the other room are all dimmable via DMX quad dimmer packs.
They are used in 8s in a fixture that has an open mounting (chandeliers),
and is rated at 50 watts per bulb. The extra lumens per watt (ab out 6x)
has been a very strategic feature for those rooms.
Not true in the US. We make heavy use of natural gas, partially because we
have tons of it that has historically been a byproduct of petroleum
production.
IME, not true. People around here who are cooling their houses in the summer
often draw the drapes and blinds to "keep the heat outside". Then they turn
on room lights to restore their ability to work and navigate.
Aside from CFLs, there is also a lot dimmable fluorescent lighting in use in
office and industry. These bulbs are 4-terminal devices and have a much
wider effective range of operation than 2-terminal CFLs.
One other comment - it appears that dimmable CFLs on the same circuit may
slightly affect each other's operation, particularly at low levels.
