Are these bulbs "instant on" or do they take a while to heat up to their full brightness after switching them on like some energy saving bulbs?
1823955
They are instant on. I'm using them in track lights and they do not need to heat up.
1823956
If they are I cannot tell the different. For me look like the are totally bright as soon I flip on the switch.
1823957
They are instant on I believe ( I'm using a dimmer ) , I wouldn't recommend buying these, I have replaced them few times since they burn so fast
2284099
They are not bad. I have had some 13 watts bulbs come on faster.. but it is not like it takes a minute before you see bright light. I do not know on cold weather. I have not tried these outside. I usually leave my outside cfl on 24/7 in cold weather, because they die out more quickly if you turn them off and on all the time in the cold.
1401130
Sorry, I'm not sure. I do know that this type of bulb has a short life compared with regular bulbs. Generally they are not on for that long in any case.
352180
If dimmer is down, they will be off....mine also take a second or so to light, but that doesn't bother me knowing I'm really saving on electricity.
777263
Yes. LED bulbs produce very little heat and that is why the are so energy efficient.
375964
They come on quickly but, like lots of other fluorescents, take a few minutes to get up to full intensity. I would say they are a bit faster then some other bulbs I bought in getting to full brightness .
375970
They're faster than most; instant on and full brightness in about 10 seconds. I use them for many purposes.
974861
There is a delay of about 1 second when you turn on the lights. If they are warm, and you turn them off then right back on, you don't get the delay. Don't know about UL listed. Mine have been working great since I got them.
131924
If used indoors this CFL gets to full brightness within 5 seconds of turning on. I do have some of these outside and when temperature is below 55oF I noticed that it takes about a minute to bring the bulb up to operating temperature and full brightness.
716959
My experience is instant on. These bulbs come on instantly to full intensity even on the coldest nights, -20f.
252125
They are LEDs so you shouldn't have a problem. I didn't notice them getting all that hot. Granted, I haven't left them on for hours at a time and then tested.
777264
I'm just a homeowner and not an expert. It sounds though like you're concerned about heat build-up from the bulb. It's my understanding that these bulbs create negligible heat. and a cut-out would be more than enough.
1058495
Yes and no. They seem to take a minute or two to get to full brightness, but it's not terribly low at first.
11927
assuming you have OEM bulbs, the BRIGHTNESS is the same; it's the TEMPERATURE that is different. To my eyes, I believe that they have a slightly warmer glow.
2080625
There is a short delay from the time the switch is turned on until there is light. At first it is unexpected and irritating, later the delay is just irritating. I made a call to Lutron (the makers of the doming switch I use for the 6 rooms I have Kobi bulbs in probably 30 bulbs) and was told that is to be expected and that neither the installation (bulbs or switch) was bad.
1117186
Yes, they are. Most CFL's are instant on as long as you are above ~32 degrees.
2284100
These bulbs are not instant on. It takes at least a minute for the bulbs to reach their full light potential. I reside in Maryland and placed one bulb in an outdoor fixture. The bulb is still working after one year. I don't turn the bulb on until nightfall and turn it off by 8 am--ergo, about 15 hours on.