Light bulb age question

[kdogg85]

How are bulbs determined to be too old. Is it from the date of manufacture or the first time electricity goes through them? Are one of these two ideas how to determine when to replace your bulbs?

 

[Deep Seven]

Mostly it's a factor of how long they've been on and what type of bulb it is. As far as I know most bulbs don't decay from dis-use.

 

[mgamer20o0]

its from how long you been using them. what kind of lighting are you using? i believe off hand the light starts do decrees after 6 months after using it. there some factors like how much heat and how many hours a day you use it also. i am sure someone who is more positive will come and so you know for sure.

 

[Krypt]

You can usually get an idea of how long they'll last from the box it comes in or the manufactures website. The box should say some thing like 2000 hours usage etc (maybe more, just a random number). Then just take out a calculator, enter how many hours a day you leave them on and divide it by the number of hours the box says and it'll give you how many days worth of lighting you can squeeze out of them. To be on the safe side, I usually go by half that amount. As we all know, some manufactures embellish a bit on their boxes.

 

[melosu58]

Moved to General Hardware and equipment discussion.

 

[kdogg85]

T5HO, have had them running 8 hrs a day for two months. They are icecap lamps, I looked on the packaging and did not see a hr limit.

 

[Greenmaster]

Off a vendor website.
Bulb Replacement Guide
Bulb Types________________________ Life of Bulb*
Normal Output Fluorescent___________ 6-12 months
Very High Output (VHO)_____________ 6-12 months
Power Compact (PC)________________ 9-12 months
T5 High Output (T5HO)______________ 9-18 months
Metal Halide (MH)___________________ 9-12 months
Light Emitting Diode (LED/non-moonlight) 5 years (50,000 hours)
* Manufacturer Recommendations

 

[mr_X]

heat makes a lamp go bad or shift spectrum early. i don't know about that guide...i certainly wouldn't keep a t-5 lamp for a year and a half. i have kept a hamilton halide lamp for 16 months without a color shift though....i guess it's up to the bulb and situation.
you should use a PAR meter to guage.