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CFL's and recessed cans #190733 12/02/09 05:21 PM
Joined: Jun 2006
Posts: 34
CDS Offline OP
This is a two part question
1 when installing a CFL bulb , do you size the bulb by the actual bulb wattage ? In other words , put a 40 watt CFL in a 40 Watt fixture . If so you can really increase the lumen output of the fixture .
2 Can you use CFL's in recessed fixtures ?
Made a quick trip to "Agent Orange" and the electrical salesman there told me , you can't use CFL's in cans because of the heat . it gets hot closer to the socket .
My opinion is that the socket is usually rated much higher than the fixture , so it would'nt matter even if it did get hotter .
If anyone has any facts or opinions on this , I would appreciate it .

Work Gear for Electricians and the Trades
Re: CFL's and recessed cans [Re: CDS] #190734 12/02/09 05:44 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
As far as UL is concerned, you can use CFL's to replace similar-styled incandescents in any fixture that the bulb will fit into, up to the rated actual marked wattage of the bulb.

In theory, this means you can get "250 watts" of light out of a 60 watt (incandescent) fixture. That's in theory.
The problem is, the bulb most likely won't fit.

That's the real problem with recessed cans. Larger CFL's won't fit in the trim.

Re: CFL's and recessed cans [Re: renosteinke] #190736 12/02/09 06:19 PM
Joined: Nov 2002
Posts: 790
wa2ise Offline
Problem is that the CFL electronic ballast (the plastic lump between the bulb itself and the screw in base) doesn't like heat. An enclosed fixture will cook the electronic ballast, and the bulb dies an early death. It won't (usually!) cause a fire or such, but people get unhappy with the bulb not lasting. The fixture will not get as hot as with an incandescent bulb, but incandescent bulbs didn't mind getting hot.

Re: CFL's and recessed cans [Re: wa2ise] #190737 12/02/09 06:59 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Yes, I've hear that .... and I'm not concerned. I have far too many restaurant customers using CFL's in their base-up totally enclosed cooking hood lights to accept that 'base up' is a problem.

Why do they use CFL's? Because they - even with the ones that die within a month - last a lot longer than incandescents in the same application .... and they're comparing the CFL's to 'rough duty' incandescents!

Re: CFL's and recessed cans [Re: renosteinke] #190738 12/02/09 07:39 PM
Joined: Apr 2002
Posts: 7,233
HotLine1 Offline
Reno's on the right track. CFL's that are 'base down' (majority of low price ones) do not like being 'base up'. The heat kills the ballast.

Along the same track as HID lamps that are position oriented, ie: base up/base down.

The CFL reflector floods should be marked as 'base up', situation is $$$.

Re: CFL's and recessed cans [Re: HotLine1] #190742 12/02/09 08:39 PM
Joined: Jun 2006
Posts: 34
CDS Offline OP
I have put CFL's in customers cans before , and have not heard any complaints , does anyone have any practical experience that their life is reduced .
If so about how much , half , quarter etc ?

Re: CFL's and recessed cans [Re: CDS] #190746 12/02/09 11:26 PM
Joined: Feb 2003
Posts: 939
frenchelectrican Offline

All it depending on which type recessed can luminaire it willbe if air tight more likey you will have issue than standard plain jane verison which they are not airtite and Non IC cans are vented in someway but with IC cans no it get pretty warm and with most CFL's with airtite cans I do see the screw in CFL have nasty early failure typically about anywhere from quarter of life to half depending on how it set up and how long it will stay on insteading of turn it on for couple minutes then off that is pretty hard on the bulb as well.


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: CFL's and recessed cans [Re: frenchelectrican] #190763 12/03/09 07:02 PM
Joined: Jun 2006
Posts: 34
CDS Offline OP
Thanks for all the input .
Like I said , I have put a few in , but in bathrooms . Consequently , limited use . That would explain why I haven't heard any problems . In the future , it sounds like I would be ok to install them when requested , and just qualify that the bulbs could have shortened life spans . Wouldn't the ballasts get just as hot inside a normal light fixture though. Also why would they make a par30 bulb if you can't put it in a can ?

Re: CFL's and recessed cans [Re: CDS] #190764 12/03/09 07:39 PM
Joined: Jul 2004
Posts: 9,569
gfretwell Offline
I have been using CFLs for about 2 years now and they are failing at a fairly good clip. These are used quite a bit since they are on motion detectors.

Greg Fretwell
Re: CFL's and recessed cans [Re: gfretwell] #190766 12/03/09 08:27 PM
Joined: Apr 2002
Posts: 7,233
HotLine1 Offline
The 'PAR 30" CFL retro should be made to burn in a base up position. I suggest you read the info from the mfg., that should be with the bulb. A reflector style bulb, I sure would think should be a non-issue in a recess.

Keep in mind, a can should not be air-tite.

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