4' T8 Bulbs

[Jsf721]

Yesterday I was working in the garage cleaning up. It was 18F degrees with the windchill. After I swept and vacuumed, I blew out the dust with a blower and closed the doors to keep the wind and dirt out. It felt dimmer in the garage and I though it was bewcasue I had been working with the sun beating in. my wife brought me lunch and said, "why is it so dim in here are there bulbs out?

Does the very cold weather affect the T8's I just installed them since last winter and I wonder if the cold dim's them. Any ideas?

 

[Gary S]

Florescent lights will start out dimmer in cold weather, but good ones will get up to full light level in a few minutes. If yours don't, something isn't right.
Mine get to full brightness in my unheated garage in about 5 minutes or so at 15-20 degrees inside.

 

[PetesPonies]

I agree . typically I will have a couple that take longer, but most are fine in a couple minutes. Are all of yours acting that way??

 

[pattenp]

Yesterday I was working in the garage cleaning up. It was 18F degrees with the windchill. .............

So what was the actual temp? Windchill doesn't have an affect on the light. Chill factor is a relative term for how the temp feels to our skin when windy.

 

[Jsf721]

it was under 25 degrees easy

So what was the actual temp? Windchill doesn't have an affect on the light. Chill factor is a relative term for how the temp feels to our skin when windy.

 

[Jsf721]

I dont think any of them came up to full brightness.

I have 4 fixtures and each hold 2 bulbs

Florescent lights will start out dimmer in cold weather, but good ones will get up to full light level in a few minutes. If yours don't, something isn't right.
Mine get to full brightness in my unheated garage in about 5 minutes or so at 15-20 degrees inside.

I agree . typically I will have a couple that take longer, but most are fine in a couple minutes. Are all of yours acting that way??

 

[starquestMM]

Aren't all fluorescents affected by temp? Do you have the plastic tube guards on them? That little bit of insulation might help.

 

[Cadman56]

If these are all new lights and this is the first time you experienced this here's what I would do. Take a light down and look at the label on the ballast. I know the T12's had ballasts with different min. start temps but I'm not sure about the T8's. Good luck and let us know what min start temp is on the ballast.

 

[tylernt]

Take a light down and look at the label on the ballast. I know the T12's had ballasts with different min. start temps but I'm not sure about the T8's.

When I bought my T8 shop lights, I had the option of regular or cold-temp ballasts. So apparently T8s have min. temps also.

 

[Mr.N]

Here in MN a few of us replace them ever year, as they get dimmer over time.
I'm talking 5-8 years apart.

 

[Stuart in MN]

Electronic ballasts for T8 lamps are typically rated for use down to 0 degrees F, so 25 degrees shouldn't be a problem. If you were blowing dust around, did some of it get on the lamps?

 

[Jsf721]

Issue seems to have past. Not sure what happened. Thanks.

 

[aar0s]

This is the exact reason i pulled the CFL's out of the outdoor lights on my garage and replaced with LED's.

 

[Kevin C]

So what was the actual temp? Windchill doesn't have an affect on the light. Chill factor is a relative term for how the temp feels to our skin when windy.

Since the lights are running at a temperature above ambient they will run cooler if there is air movement over them. So as odd as it sounds, they experience greater cooling with wind or as its called, wind chill.

Not the best thermo term but the effect is the same.

Since fluorescents get dimmer as they get cold, it makes sense that opening the door in cold weather would reduce light output. I spent a lot of time testing fluorescent lights in environmental chambers at very low temperatures. The output drops with temp and even when they were stabilized at low temps they were dimmer.

Just because the ballast will work at a really low temp does not mean that your are going to get a lot of light (I tested down to -50°F). Things get a lot better once you get above -20°F.

I was testing how well LCD's displays work when they get cold. Florescent back-lights will work to some crazy low temps, LED's were never even bothered. The LCD's themselves start to freak out at about -28°F. The response gets really , really slow.

One thing I did learn when running environmental tests... Most silicone gels freeze at -40°F. Rule of thumb, never let implants get really cold.