high temps inline fan help

okay so where I am were reaching the hottest part of summer. i run a 400 watt hps in a 3x3x6 tent with a 6in 400 cfm inline. the problem is my temps have been staying steady at about 86-88. have made it up as far as 92. i run my lights at night have to keep fan full speed. my question is would my fan be more efficient if i put it in the tent connected to the carbon filter? as of right now the fan sits outside the tent with the duct connected to it. prob atleast 15ft of duct with some bends.

Every foot of ducting and bend in the ducts reduces the efficiency of the fan. Short runs are best regardless of where the fan is located. Both of my fans are outside the grow room. Take a look at my thread below. I ran a 400w HID in the same size closet.

Adding a second fan separate from my lighting exhaust finally got my temps below 80 degrees with outside temps 100+. Ultimately I went to LED to get down to 76 degrees at night 78 days. But that's an investment of serious cash!

I had to hack a house fan and run ducting from outside the room as an intake. Just an option. I cut a 10 gallon bucket in half and cut a hole in the bottom the size of the ducting, sealed it over the the fan and ran it from outside the room. Works like a charm. Brought the temps down some 10 degree's. This was in addition to my two 475 CFM fans. But I have two rooms, Veg and Flower. Can't wait for winter!

I've been dealing with high-heat and have been adding fans along the way. I currently have 2 6" inline fans moving almost 500 CFM in a 5x7x7 grow room and my temps still remain in the upper 80's. I have a 400w MH and a 600w HPS running. The problem is that my exhaust vents into the rest of the basement and sooner or later my basement is also in the mid-80's....where my intake is drawing from.

The only thing that keeps me from panicking is the fact that pot plants naturally grow in some pretty hot places and do just fine. Look at the outdoor growers that can't control temperatures at all and their plants show no sign of heat stress. While having our plants in the mid-70 degree range is favorable, you shouldn't go nuts when temps are in the 80's.

You can't intake from your exhaust....you know that. Unless you can, so you do.

Else, one has to change. No way around. I have been in these loops before. OTH, mid 80s is OK for awhile. Any hotter, (and certainly it can get hotter,) will slow growth, I think, unless we add CO2.

So, what adds heat and how to transport heat? I've been using a hot box concept. Every thing hot, ballast, air pumps, the AC unit, the Veg tent, all exhaust into the box. Then the box is exhausted out the top into the roof vent from the bathroom.

Bigger ac needed..

You cannot cool a room lower then outside temps... Here it's been 96 all week... You need a ac to keep the room cool, plus more because your light has heat too..

Doer said:

You can't intake from your exhaust....you know that. Unless you can, so you do.

Else, one has to change. No way around. I have been in these loops before. OTH, mid 80s is OK for awhile. Any hotter, (and certainly it can get hotter,) will slow growth, I think, unless we add CO2.

So, what adds heat and how to transport heat? I've been using a hot box concept. Every thing hot, ballast, air pumps, the AC unit, the Veg tent, all exhaust into the box. Then the box is exhausted out the top into the roof vent from the bathroom.

Click to expand...

I vent straight out a window

The answer is cooler intake temps.

Summer is a killer and sometimes you have to step up and buy a portable a/c unit or bring in cool air from the house. You need cooler air going into the tent.

Pulling hot air through isn't going to help no matter how fast you move the air, it's still hot air.

prosperian said:

The answer is cooler intake temps.

Summer is a killer and sometimes you have to step up and buy a portable a/c unit or bring in cool air from the house. You need cooler air going into the tent.

Pulling hot air through isn't going to help no matter how fast you move the air, it's still hot air.

Click to expand...

I totally agree with all of this. The temperatures (outside and inside) that I'm experiencing right now is not the norm for upstate NY. We've been having over 90 degree days for a stretch now and sooner or later things will cool down to where my basement is much cooler than it is now. I understand the "loop" thing I have going on, and I have the intake well away from the exhaust. My problem (how did this thread turn into my issue?) is that I have no other option....you'll have to trust me on that.

Yes, I could get a portable A/C unit, but I have a wife......a wife that's been watching me spend a lot more money than I told her it would cost to grow weed. I'm sure there's a few readers on here that can relate. To go out and spend yet another couple hundred bucks will be the straw that breaks the wife's good humor about all this.

As I said before, pot grows in very hot climates. Jumping through hoops to get to a more comfortable temp for a relative short period of time is really not needed. My plants range from seedlings to 3 weeks away from harvest and not one of them are showing signs of heat stress.