I am pushing fresh air with a 440cfm fan through the light and exhausting on the floor outside the tent in the same room. The glass around the light is cool to the touch. There is a significant feeling of heat when you are not touching the glass. I’m runniing a 220cfm fan to vent the tent: drawing out at the top (hotter air) and bringing in cooler air below near the plants (not on them). Lights on 80-84 Off 60-65. Humidity 30%-40%
I guess 450W would have been a better choice. Your temps should be more manageable.
@Hballer21 Now that I dialed in temps I can’t dial in my humidity. Temps in my garage in the 50’s at 35 RH
In the tent with a humidifier set at 55 I get RH levels in the low 20’s. Tried lowering the Fan, opening more vents, closing more, tried raising the exhaust to full throttle. Going to keep at it until I get!
Bring your ambient temps up. 50s is too low for a nighttime temperature. During veg, I put a couple of light bulbs in there to keep the temps up when the veg lights were off. Experimented with different wattage bulbs to bring the temps up. It was suggested taking a fish tank heater $10 and putting it in a 5 gal bucket of water in the grow space. That’s better because you can use it during flower as well, when it needs to be dark.
Get your day and night temps regulated first, reliably. The water heater will add humidity, as will the increase in temps above the 50 degree mark. Once you have that set up, then we can go after the humidity.
Ok. Well, determine your temperature cycle (day/night) and simulate it, monitoring your relative humidity. Advised to run lights at night to not have to supplement tent during colder part of the day.
@Hballer21 Thanks for the help. .Much appreciated. Looks like I have my air cooled lights venting hooked up wrong. Will redo everything and hopefully now I can dial in the RH as well now.
@Hballer21 On your fan blowing air threw the lights am right by you having the 440 CFM there? Reason asking is I am thinking of just using my exhaust fan instead and worry about it later replacing it when I go into flower when I do need it then to exhaust everything out. Or should I later get a smaller cfm fan because it’s just blowing threw the lights and out?
Did you see the pics that I posted? 440cfm through the light and OUT OF THE TENT. I have 220CFM exhausting the tent. I have a little less than 45 cubic feet (3x3x5). I am changing the air 4.8 times per minute. That is a LOT. Slower will increase my humidity (if I want to). Venting a hot light will depend on how much you want to reduce the heat. Mine is 50+ without the fan. With the 440cfm fan, my heat is 15+ which is acceptable for my target temperature. I’m not sure how many times you should exchange the tent air (not the light). I think it’s a minimum of 2x per minute. But, check with others on that. I only know what is working for me.
@Hballer21 Yes I did see the pics. And your info on venting is going to be of great help. Thank you. Being in the garage this evening and passing my tent I realized I still had to have a exhaust fan. Especially later to the carbon filter during flowering. When talking about the 50+ and reducing your heat. Are you talking about the difference between the outside of the tent air vs what’s the temp is inside the tent? Let’s say my garage temps are at 50 degrees and inside the tent it’s 102 degrees. So the difference would +50 degrees. I’m thinking the 220 CFM fan would be fine. My guess is you are running a speed controller to it? Or you using the humidity controlling monitor there instead of in the exhaust fan? Interested to know your thoughts on how to control both fans.
@Hballer21 There is no need for me to do a summer grow. But will no doubt be high temps of 80 to 90 degrees sometimes in my garage. Could i use a speed controller on the 435 CFM fan to the light to slow the fan down to let the exhaust fan do a better job getting that heat out of the tent? Not sure because of my 50 degree temps in the garage that it is needed now?
If you’re adding heat to your tent and the temperature differential is higher than outside of your tent you can exhaust much of the heat to your target range. If your garage is going to be 80 to 90, this is not the plant to grow unless you have an air conditioner.
First time grower located in Boston. I just set up my Oppulent 3x3x6 tent in the basement today. where the ambient temp is a balmy 55 degrees . Inside the tent, with the HLG 100 the temp got all the way up to 61 after 6 hours. I thought it would be much warmer in there. The 3 plants are still on the seedling table in our dining room but time is running out. They have reached about 8 inches tall with nice fan leaves. I am afraid if they go into the tent it will not be warm enough for them. I am trying to get the conditions right in the tent before moving them into their permanent home . Help!
