Heat problems 2000watt grow

DemonTrich said:

dunno, the caulk was 11.95 a tube. 30 min rain/weather ready 100% silicone. same stuff I use to seal windows, bathroom, ect. ive had my hoods for 2 yrs now and caulk is still holding strong.

GE maybe,.

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Thanks man. I ended up trading the 6 inch blockbusters for two 6 inch cool-tubes. So far, this is the only way my temperatures are even somewhat manageable. This carbon filter is KILLING CFM. I took off the prefilter since I have a dustshroom for an intake anyhow. I'm steady at about 83 at the top of my canopy, but my plants are still pretty short. I'm thinking about just scrubbing the air instead of trying to cool 2000 watts through a carbon filter

I know scrubbing the air isn't as efficient for smell, but due to cannabis being legal here, smell maintenance is just security for being robbed really. I'm thinking about buying another 6 inch fan and hanging the carbon filter in the corner of the tent, and leaving the end of the cool-tubes open having my 8 inch turned lower, pulling hot air through them. My tent is against the wall on one side, or I would cool the tubes separately from the grow. However, I just dont have enough room in the room the tent is in for that.

Do you think hanging the carbon filter attached to a 6 inch fan turned pretty low, would still help smell? I think I should have run two 4x4 tents with two separate fans/filters. Oh well, you live and you learn.I can hang the carbon filter beside the end of the cool tube/exhaust opening, but not in-line. Not enough room .

I can grab a pretty cheap six inch inline fan; just wondering what you think I should do?

I was having heat issues even with my 14k portable a/c. cannabis john over at thcfarm gave me a couple ideas.

1 lower your scrubber fan speed a bit to creat some positive pressure. not too much, but when you open your flower room door, you can feel the pressure a bit when opening. this make it so the scrubber isn't sucking out too much air that the intake fan cant replace in time with cooler air. this alone dropped my temps 3*.

2 im not sure how you have your intake fan set up. I have a 90* elbow inside my tent. I had it pointing down (I know stupid me, hot air rises, cold air sinks). I positioned it blowing up vs down. this again dropped my temps another 3-4*.

now once winter is almost upon us, my flower room was too cold (I hate when my flower rooms too cold--insert sarcastic tone here). so I turned the 90* elbow back down. then my floor was 69* and my canopy was 73*. so I ended up removing my 14k btu ac and put in my back up 8k btu, now im running 77* canopy and 75* floor. perfect for winter and I save a bit on my power bill....... well until I added another 600w in veg (now 1200w) and turned back on my big ass ultrasonic fogger system (8.2amp power draw).

I would run your hood cooling separate from your scrubber. I tried to do that in veg and it worked ok in winter, once summer came I had to undo everything and keep things separate once again for my temps to get to where I want them.

I also run 2x8" 720's for my 3x hoods.

I would worry 100% about mj grow smell, even if your legal. im legal and grow in an unsavory area of Detroit. you bet your ass I have zero smell emitting from my "shop". don't let anyone know you grow. its safer and easier this way.

DemonTrich said:

I was having heat issues even with my 14k portable a/c. cannabis john over at thcfarm gave me a couple ideas.

1 lower your scrubber fan speed a bit to creat some positive pressure. not too much, but when you open your flower room door, you can feel the pressure a bit when opening. this make it so the scrubber isn't sucking out too much air that the intake fan cant replace in time with cooler air. this alone dropped my temps 3*.

2 im not sure how you have your intake fan set up. I have a 90* elbow inside my tent. I had it pointing down (I know stupid me, hot air rises, cold air sinks). I positioned it blowing up vs down. this again dropped my temps another 3-4*.

now once winter is almost upon us, my flower room was too cold (I hate when my flower rooms too cold--insert sarcastic tone here). so I turned the 90* elbow back down. then my floor was 69* and my canopy was 73*. so I ended up removing my 14k btu ac and put in my back up 8k btu, now im running 77* canopy and 75* floor. perfect for winter and I save a bit on my power bill....... well until I added another 600w in veg (now 1200w) and turned back on my big ass ultrasonic fogger system (8.2amp power draw).

I would run your hood cooling separate from your scrubber. I tried to do that in veg and it worked ok in winter, once summer came I had to undo everything and keep things separate once again for my temps to get to where I want them.

I also run 2x8" 720's for my 3x hoods.

I would worry 100% about mj grow smell, even if your legal. im legal and grow in an unsavory area of Detroit. you bet your ass I have zero smell emitting from my "shop". don't let anyone know you grow. its safer and easier this way.

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Dude. You are the effing shit!!! THANKS SO MUCH FOR THIS INFO!!! You seriously saved me so much freaking time and hassle. I just ordered another 6 inch fan last night so I can start scrubbing soon!!!!

Hilarious, my intake vent is angled down at a 45 degree so I don't ravage my plants with fast air. I'm going to get an elbow today to point her straight up... rofl... thank you so much!

I forgot to tell you, the ambient room temperature was only 74 degrees. My 12k BTU AC was NOT on. The central heat was actually on in the house (although vents in the grow room obviously closed).

Once I start scrubbing, I will tweak my intake to get a slight positive pressure in the tent. Won't smell only leak into my house this way (which im not worried about)? I hear people don't like positive pressure when trying to deal with smell. However, I would think that just outside the grow room/tent itself would escape a little smell, not the exhaust to the building/grow if it were scrubbed properly.

So now the real question.... Do you think my cool-tube set-up vs my giant blockbuster (26x26inch) hoods, will yield that much differently? I still have the option to return the cool tubes instead, but I'm kind of liking the extra money in my pocket. With so much heat in such a small tent, I literally lost over 10 degrees by switching to the cool-tubes. However, if i start scrubbing instead of running the carbon inline... I'm thinking the big hoods will work.... at least for the winter. Damn it I REALLY don't want to remove the hoods again...... but I will if you think the yields are that much greater from a real hood vs tube. I will be using two single hortilux UVA/UVB horticulture t5 bulbs for supplemental lighting... four if i can keep the temperatures down. Probably nothing else.

I've heard mixed reviews on big hoods vs cool tubes. I know the concavity of the tube diffuses the light differently, lowering available lumens to be photosynthesized vs flat glass. However, placing the tube closer, you gain those lumens back.

Probably cool tubes to be safe with temps? HVAC is fun haahahah.

Regardless; I'm flowering tonight lol. Thanks again!!!

Also should I hang the scrubber/fan combo right next to my cool tube exhaust opening? Not enough to restrict the exhaust, but to the left or to the right of the opening? Carbon scrubbers work better the higher they are placed, correct? I think the blockbuster hoods may be too heavy for that AND another 6 inch hurricane fan lol. I may have to stick with the cool-tubes. I really like not hitting my head on sharp corners .

I tried to run hoods in my tent and I went back to my cool tubes. The goal with a tent is to keep the temp inside the tent as close to the outside of the tent as possible. I have 2x 600w in a 4x8 tent. I run a 440cfm fan for exhaust hooked up to a filter in the tent. The exhaust goes into a window well in the basement. Temps in the tent were about 5 deg above the outside, I needed a fresh air intake. I ran a snorkel into a tub that sits on top of the window grate and draws in fresh cool air from above the grate (air in window well gets warm, can't use it for intake too). I have that hose running passively to the lower part of the tent on the outside. It's getting cool outside (CO) but this method is keeping the temp inside the tent within 1 deg of the outside. About 70-72, I ordered a damper and a temp control module I'll hook up for the winter, but for now it's working great.

Top tube: exhaust out
middle tube: passive intake w/ snorkel
bottom tube: 2nd carbon filter for room tent is within to catch any extra smell, plus it's the smoking room too.

Passive intake (for now) directing cool air into bottom of tent.

blackforest said:

I tried to run hoods in my tent and I went back to my cool tubes. The goal with a tent is to keep the temp inside the tent as close to the outside of the tent as possible. I have 2x 600w in a 4x8 tent. I run a 440cfm fan for exhaust hooked up to a filter in the tent. The exhaust goes into a window well in the basement. Temps in the tent were about 5 deg above the outside, I needed a fresh air intake. I ran a snorkel into a tub that sits on top of the window grate and draws in fresh cool air from above the grate (air in window well gets warm, can't use it for intake too). I have that hose running passively to the lower part of the tent on the outside. It's getting cool outside (CO) but this method is keeping the temp inside the tent within 1 deg of the outside. About 70-72, I ordered a damper and a temp control module I'll hook up for the winter, but for now it's working great.

Top tube: exhaust out
middle tube: passive intake w/ snorkel
bottom tube: 2nd carbon filter for room tent is within to catch any extra smell, plus it's the smoking room too.
View attachment 3535376
Passive intake (for now) directing cool air into bottom of tent.
View attachment 3535377

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Nice looking set up. Very interesting how you incorporated your exhaust and carbon filter. I may have to set up an intake from the outside eventually. Hopefully not.

And I'm in love with these cool tubes so far. Temperatures are around 83 on day 1 of flower at the highest branch. I'm going to remove the carbon filter and attach it to a 6 inch fan when that gets here tomorrow or the next day. Maybe I can turn my exhaust down from max then.

imo those types of cool tubes your losing light above the tubes. with a cool tube with a hood or hoods it reflects the light down and to the sides, vs down/side/and up with your current tubes. I went from a cool tube with an xxl hood to my big kahunas. the BK are Fn awesome hoods. fully adjustable light sockets (up/down/left/right adjustability). so I can sorta dial in my light spread pattern. and it does make a difference when I adjust mine.

if you exhaust out your scrubber, then yes, higher is better. heat rises, cold air sinks.

also put a couple small fans on the floor pointing up. this will help recirculate the cooler floor air up into the other fans to help cool the room as well. now I also have 3x18" fans (on high) that blow at each hood to get rid of the "hot spot" of air under them. now the oem bases that come with those hoods take up a HUGE foot print (2'+ radius), so I used my old weight gainer type of containers (milk jugs will work also), made a batch of quick set concrete, wrapped fan metal pole with grocery bag, poured in the quick set, stabilized the fan pole (w/o the fan for ease of working) and let dry. once 75% dry, slowly remove fan pole and let fully dry. now you have a small fan base foot print, and is super sturdy and adjustable. I did this for 4 of my 18" fans for about 3 yrs ago and still working perfectly.

83* is perfectly fine in veg, but you want those temps a little cooler. 81* max (I like 75-77*), and last 2 weeks of flower try to drop to 77* or less. I like 73-75 max.

What is the purpose of having the filter on the exhaust line for your lights? That is where your problem lies. If you are looking for more cooling capacity you need to isolate your exhaust for your lights and the exhaust/scrubber for your room. (1) To cool your hoods, pull cool air from outside or air conditioned room through your lights and exhaust out. (2) to scrub air in room place carbon filter above lights, add inline fan, then ducting out of room. Basically you need (2) exhaust loops. one for hoods and one for room. good luck

I run a similar setup to yours I have three 6 inch block buster hoods with 600w hps in each one, with all running my grow room is 75F. Biggest things that helped my setup is having my tent have 2 strong fans running 24/7 one for exhaust that I hang inside my tent and an even more powerful one jamming cold air into my tent, this causes positive pressure. Good luck mate!

Mountainfarmer said:

What is the purpose of having the filter on the exhaust line for your lights? That is where your problem lies. If you are looking for more cooling capacity you need to isolate your exhaust for your lights and the exhaust/scrubber for your room. (1) To cool your hoods, pull cool air from outside or air conditioned room through your lights and exhaust out. (2) to scrub air in room place carbon filter above lights, add inline fan, then ducting out of room. Basically you need (2) exhaust loops. one for hoods and one for room. good luck

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Yes, this was my problem.

I set up a scrubber about 3.5 weeks ago connected to a six inch fan. Put that above my cool tubes. Now I'm maxing out at 79 on my highest node on a warmer day, and 65-75 below the canopy. Lights are dropped to about 1.5 feet above the canopy. Can get a little cold during sleep cycle 53-65, but usually in the low 60s. Had to do this before I even started flower.

Smell is also much better this way. You can only smell it if you go inside the tent or put your nose right up to my exhaust right outside the house. If you step back six inches, you smell nothing.

I'll rework my HVAC again before I grow again to accommodate the blockbuster hoods or something similar and get rid of these cool tubes.

I had some salt lockout issues due to not enough run off (RO machine not big enough), but using my bad ass 60 ppm tap water (denatured for 24 hrs with some air stones) instead. They went from getting 8 gallons every two days to 14 gallons every 2-3 days. I don't think they mind the spring tap at all.

Thanks for all your responses!

Here's some pics at about 3.5 weeks into flower. Maybe a hair behind schedule, but they are bouncing back nicely.

roorsmoker said:

I haven't posted anything in a few months. Been busy moving/working.

Problem: Temperature is topping out in the upper 85+ degree area, despite plenty of airflow and an AC unit. I'm NOT flowering, nor am I using HPS until I correct this ventilation issue.

-I have a 4'X8'X6.6' tent with a 6 inch 545 cfm Vortex exhaust running full speed, pulling through two Apollo enclosed hoods with a 6 inch iPower carbon filter in front of the hoods. The bulbs are exactly 4 feet above the floor of the tent. Too low possibly?

-The tent is mostly empty of plants (9 seedlings taking up about 2 square feet). I had my 2 foot HO t5 envirogro on with the thermometer underneath the lights, with the t5 still on. Maybe the t5 light fixture absorbed too much heat and I got a bad reading? Thermometer is a Caliber IV digital. Maybe the black absorbs too much heat and gives a bad reading?

-The two hoods are each holding 1000W Eye Hortilux SuperHPS bulbs.

-I have an active intake blowing in the bottom opposite side of my exhaust. It is an 8 inch 745 cfm Hurricane sucking through an 8 inch Dustshroom (HEPA alternative) and blowing into the tent. I have an IDEAL air controller plugged into the 8 inch hurrcane. It's turned down to about 40%, as to not create positive pressure inside the tent.

- There is a 12000 BTU portable AC cooling the room the tent is in. The AC exhaust is blowing outside the house, along with the tent exhaust.

I know the obvious question is, "why don't you use the 8 inch for exhaust and the 6 inch for intake?" I could, but I would need adapters for my 6 inch flange (or a new flange), and adapters for my 6 inch hoods. And also a 8" to 6" reducer for my Dustshroom.
-Do you recommend I raise my lights/remove exhaust ducting? Buy better hoods (they seem pretty air tight, they have screws and a rubber seal)? Add a cheap 6" can-fan in between my two hoods? Any other ideas, like toughing it out and buying adapters, making the 8 inch fan my exhaust, and my 6 inch fan an intake?

Passive intake was actually worse despite tons of negative pressure. Maybe not enough passive intake?

Posting many pictures, sorry for the detailed question.

Anyone with any experience in HVAC at all, chime in please. It's also going to get very, very cold where I am in the winter. Its already in the 50s at night.

Without the HPS on, the temperature under the T5s drops about 6 degrees as opposed to no ventilation on at all.

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sorry didnt read the replys yet. but i dont think you should be exhausting if you have ac. if you dont use ac then the vented air shoud go outside the house or building not into the room that the tent is in eventually you will just suck up the old heated air back in the tent and if your ac isnt exchanging heat from the outside its not going to work. you are just recirculating the heated transferred heat right back inside the room using even more electricity and doing nothing but basically providing a fan