Each of those 5w leds have an operating temp of around 145° F, a 100w cfl produces much less heat than 20, 5 watt led chips, different lights produce different heat at the same wattage.
Correct about the latter. But when I said a regular bulb, I meant a 100w incandescent bulb. But his light, each of those leds is getting less than 2 watts.
People think that these led grow lights are just super cool but that isn't true, they put off a good amount of heat. The leds are attached to heatsinks being cooled by fans blowing the heat away from them into the air.
Exactly buddy! If you are getting into led because you think it's going to cool your tent down, unless you are building it yourself, they dump quite a bit of heat into your tent. I've mentioned swapping out the light below (the 1200) for a cooled 1k HID, my temps went DOWN 4 degrees.
If there is no air exchange going on in your tent via a vent fan I am almost 100% positive that your tent will overheat in just a few hours, but I could be wrong.
You would be. (I'm not trying to be argumentative, I just know for a fact)
Here is mine, that has a 594w actual pull, & I think 240 leds. The tent does not overheat. & I'm sealed with co2 (co2 makes it even hotter)
So, I'll only mention it once more but if that is a 4x4 tent, with just that light, he is not going to need ventilation because of heat...that's they only thing I was trying to clarify. The heat will be fine, I'm absolutely sure of it. I have a light very similar to his, but about 6x hotter. & unless you are in the heat of summer (any light is too hot then) Heat is not going to be a problem. Open up the top sock, & a couple bottom ones and convection will move the air.
Plus, you need to exchange the air in a tent anyway to get fresh co2 in.
That is why he will need some ventilation. But even one simple fan clip fan at the top or bottom (depending on which way gives him the best temps) & an opening large enough for that fan to pull fresh air in will be fine. More is always better, but that is the minimum standard he needs. I think maybe I could have been clearer at the beginning. I wasn't saying he doesn't need to vent the tent at all. I'm trying to clarify for him that his light is not going to produce enough heat that he needs to invest in a ventilation system. In fact, depending on where he lives, & how many plants, pretty soon, he may need more heat.
It's the air he will need to be exchanging. But not because his light is going to be too hot. That light is very small. He needs fresh air in the tent, but he doesn't need anything extensive.
Hope it's all good 3N1GM4. I'm genuinely not trying to be a dick if I'm coming off that way. I'm just trying to clarify for the OP why he needs air movement. It won't be because the light is producing too much heat. It will be for fresh co2. I know because I have the light he has, except mine is the steroid version.
But we are eye to eye on the led heat issue in general. A lot of people switch from HID thinking LED will be cooler. & as you said, that is not necessarily the case. Their are factors to consider like ambient temp outside the tent, whether or not you want to have duct work around etc.
But considering that you need to spend a good chunk of change for an led that will perform to HID standards (the best I've seen anyone do is a $1,000 & the light was practically given to him) I think a lot of people would be better served to run a vented hood with at least a 400 ft3 cfm fan if their grow space allows for it. A 1k hid throws a ton of heat. (I don't know how these people are running 6 DE's in a space) But in a vented hood, with a high cfm fan, much of it is quickly removed. I've not seen a vented LED yet...so any heat they produce, is just dumped right into the space. Is it cooler than & a wide open HID? Depending on wattage, probably. Is it cooler than a properly cooled HID? In my experience, no. One system funnels the heat away from your space...the other one, is just dumping it right into the space. So, weigh all those factors before you make the leap.