Hello all! I’m new here, and new to growing also, or at least on my own. I grew with my brother many years ago when it first became legal in Michigan, so I have some degree of understanding, but I’m struggling with figuring out the best way to run my equipment, particularly the climate side of things so I thought I’d drop in here and see if anyone has any thoughts!
Ill start with what I’m working with. I have a 4x4 grow tent from Vivosun, inside there is a 600w hood. Currently on MH, but soon switching to HPS (week 1 into flower). I have one 6" inline fan, a 50 pint dehumidifier, a dual line portable AC (Idk what you call them, it has a line that pulls air and a line that pushes air) and one clip on 6" tent fan. I can’t for the life of me manage to get my temps and humidity stable. Im like 77 day temps, 68 night temps which from what I understand isnt horrible, but I live right off a lake and my god is it humid here. The room the tent is in sits at around 60% right now, and in the tent can get up towards 70 without even trying. I need to get this humidity down pronto as the last thing I want is bud rot. How would you suggest running the inline fan, dehumidifier, and portable AC to maximize the balance of heat and humidity? Right now I have the inline fan outside the tent and its blowing air down into the top. Then, I have the sucky side of the portable AC running into the tent which is connected all the way through the light hood to extract that heat and vents out a nearby window. Ill get some pics on here too so you can see because I can be terrible at explaining things.
I feel like Im torn between positive and negative pressure in the tent, and Idk which is the better call. But, I need to get that humidity out without turning it into an oven. Any ideas on this situation would be greatly appreciated and immediately attempted. Thanks in advance!
I’ll jump start the convo with a simple analogy.
When you drive your car down the road on a hot muggy day with the windows open, the AC isn’t gonna do much. Same with your tent. It’s less about controlling the heat/humidity in the tent, and more about controlling the “weather” (the room the tent is in). Then tent conditions become more about controlling the air flow thru the tent, matching more to the room.
Sorry if I’m being a little cryptic, I just got out of surgery, and am a bit foggy atm.
I totally understand the analogy, just not sure what I can do about. At least not in a major way. I have a window AC unit I could slap in the window, but I do want to get the room light proof too, and I do really like the idea of being able to vent the heat from the lights directly outside. Everything I’ve read says this is the constant battle, and they weren’t lying! sigh
Realistically, what are my critical maximums for humidity? We are still on week 1, no flowering yet. 50%? 60%? I’ve read that one should strive to gradually reduce humidity as the weeks progress, and Im pretty majorly stressing that as something I may be unable to do. Its 58% humidity outside today, goes to over 70 tonight. It’s just gross.
The air intake should come in from the bottom of the tent. The hot air should be vented from the top.
I agree keeping the vents short will help with flow.
This sounds backwards, your inline fan should be exhausting stale/humid air out air out at the same time it passively pulling fresh/dry air in.
So, I’ve never used MH/HPS lights but, it sounds like you are pulling heat off of the lamp with your a/c and cooling it before it goes out the building? why not cool the incoming air and use the other fan (or another fan) to cool the light?
Is your dehumidifier inside the tent or is it outside the tent in the lung room? Dehumidifiers create a lot of heat and I’ve found it’s a lot easier to control the tent environment when I have the Lung room more stable. This way, I’m pulling in dry/cool air and exhausting the stale/moist air. My light doesn’t heat up too bad so, temps kind of fall into place and, if it gets too hot inside the tent, i just unzip the bottom and hold the flap open 4 or 5 inches to get better airflow from the room. The hotter it gets outside, the more my house a/c runs and the easier it is to maintain temps.
If this is true, it’s doing nothing with tent air, and just cooling the lights. I’d put the fan inside the tent, and use tent air to cool the lights. This way it would double as a tent exhaust fan as well as cool the lights. The warmer air from the tent should be plenty to cool the lights, if not, use a radial blower instead. That’s what they used to sell with light cooling kits i saw back before led’s.
All solid. I went down a little bit ago and sorta had a lot of that dawn on me. So now inline fan is in the tent, running through lights and out the window directly. I guess i dont know how those portable ACs function. Is the aie sucking in the air its cooling directily? Or is that just circulation? Why do they even have a tube for intake if thata the case. Wouldnt one always just want the air being cooled to be ambient? Why have a hose for that function?
To that end since i only have two things thst move air, i put a line on the top port and connected that to the ac sucky line. If im very very mistaken about how that all works please do correct my ignorance. In my mind, if that is the air its cooling why not let it cool the hot air inside the tent rather than the hot air outside? At least its helping exhaust! Again, i could be very wrong lol.
A/C’s are a dual system. There’s a radiator-type part that gets cold when the compressed gas inside of it evaporates and flows through it. It absorbs heat from the air in the process, which is why it’s cold. There’s actually no such thing as cold, there’s just lack of heat (energy). This fan recirculates the air you want cooled.
Then the gas moves to a compressor, which compresses it back into a liquid, which emits energy in the form of heat, and it goes through another radiator-type part that is located outside, where the heat is dispersed outside the room you’re trying to cool. Think of the big fan blowing upwards on an outdoor home A/C.
Many portable A/C’s have only a single duct, and are less efficient at this process for the obvious reasons explained above. So this is why you have one inside hose; to condition the inside air, and a separate hose to exhaust the heated side. Making the inside and outside parts all in one, portable unit.
(Anyone correcting a slight.mistake here or there, plz be kind… I’m on a phone, with a head full of surgery painkillers lol)
Is there and air intake at the top of the tent?
Intake should be at the bottom.
Also if the tent is being vented outside?
I find if i vent my tent outside i cant keep a stable RH. I vent my tents into my lung room and it’s alot easier.
Not useing LEDS you are dealing with more heat then most of us so I understand you have tk do some things differently, but those temps you lised are ideal, in fact the temperature can go up to 80ish with no problem…
My Opinion only,30 years hvac exp…you want the cooled/a/c air coming in the bottom of tent and your light heat removal and the two up top also taking air out causing circulation from bottom to top. I don’t see a carbon filter? smell no problems. The portable a/c only conditions the air the room is in, so if you pump in cold air up top it is taken out by the light heat removal system… maybe condition the whole room with the a/c that will remove humidity and cool the room, then open left bottom side vent and let the cool air flow in and be dragged out the top with the light heat and top of tent temperature.Then when your room humidity is right and low it will be cycled up and out the tent exhaust fans, never off. tent temperature equals the room temp. if that makes sense
Thank you all for the info! I have the heat going right outsite because that portable AC already struggles to cool the room down, id hate to make more of a problem. I have the window-shaped hose end thingy from the AC in the window but otherwise the gap has been sealed up. Its not perfect, but its better than it being just an open gap ya know?
As far as the temps, yeah I know the temps are ok, its more the humidity im losing the battle against. But tonight i moved all the stuff around, light proofed the room, and now i have the inline fan in the tent, going through the lights and directly outside, and the AC inlet side pulling some extra heat right out through it. So two lines running outside. Hopefully we will have a drop in outside humidity soon.
ok, if you’re using your a/c to pull air out, where does the outlet side of the a/c fit in, where does the cold air go? If I were to direct connect an a/c unit to my tent, it would only be used as a fresh air intake so, it would pull the air from the lung roon through the a/c and blow cold air into the tent while the inline pushes or pulls stale air out the top.I guarantee you the fan running in your a/c is not strong enough to pull enough cfm to properly exhaust the tent, that’s what the inline (induction) fan is for. It can replace all the air in your tent in less than a minute with fresh air from the room. You need that air to turn over, the plants need fresh air coming in so they can breathe. Is the inline dedicated to cooling the light? If so, I would get another to exhaust the tent as well.
upon further inspection, the a/c goes in the right side of the light? how do you think it goes out the left side with nothing attached there, what is the tent size? it looks 5x5?, is the fan a 6inch fan? can you make an exhaust to the outside or to the attic? without to many changes, there are metal tees for duct work 4x4x4 tee, 6x6x6 tee, where two supply or exhaust can be connected together for you out the top ventilation, i am unsure what a/c that is? your blowing cold air in, and exhausting the room temp hot air up something which is correct for a spot cooler, I dont see other opening on the bottom of the tent except pull flaps with velcro one side. so either cool and dehumidify the whole room and pull it in from the bottom somewhere, thing to decide if you want another fan or just 1 bigger one to exhaust? just a thought.
I’ve got 2 tents in this room and it does great. But I have led lights so not near as much heat as the MH or hps. My ac also has a dehumidifier function.
because a spot air conditioner in a room must send the hot air outside,or the air conditioner won’t work in a room. the air conditioner takes the air from the room and removes the heat and humidity by the cold radiator or evap coil, then the heat that is absorbed from the machine and freon is sent to the condenser which is usually out side of your house where it dumps the heat that was gathered by the refrigeration process. definition of a/c is to remove heat from a structure and move it to a less objectionable place which is outside. through the cooling process you are also dehudufiying because that is where the btus reside in the moisture of the air.
So, the processed air blows out the center. The inlet side is on the right, the exhaust is on the left in the back. So i think the original idea is were that running like normal youd have both inlet and exhaust ports in the window? But, youd think youd wanna pull the intake from the room.
This AC has a function where it only circulates. The compresser doesnt run nor does the front blower fan. Its a nice unit, i just think it may not be running as efficently as if it were new. Its at least 5 years old.
