Soon to be a new vert grower, need cooling advice.

[Bennyweed1]

Hey Icmag..... I love this section. Once I read it I have never thought about growing horizontally again and I have had great success with a horizontal reflector before. The results with a vertical bare bulb are just mind blowing! Plain and simple.

So enough with my jibber gabber. Here is my scenario and I have all the equipment picked out..I am just waiting for my basement to become available.

I will have two 5x5 bloom tents. Each tent will have a single 600w HPS in it. Now in terms of cooling, will what I have be enough to keep things in a ideal range?

Both tents will splits a single 293cfm S&P inline fan for their intake and both tents will split a 560cfm fan for exhaust. So basically 146.5cfm intake and 280cfm exhaust. Will this cut the cheese or do I need a beefier ventilation system?

Keep in mind the heated air will be pushed into a large concrete basement that naturally stays cool year round. Both tents will be housed in the same basement.

Please tell me I can get by.

 

[TheGreenReaper]

What are the ambient temps of the air coming into the tent?

I use a 300cfm 6 inch on a 6x4 reducer into the tent for a naked 600w and I would like it to be about 6 degrees warmer, it holds at 70-72. But ambient air is in/from a basement so often 55-65f. You should be fine as long as you arent sucking 75f air into the tent and have a way to move air from the bottom of the tent to the top where you are extracting.

 

[Grizz]

guess its going to depend on temps in your basement now and in the summer, i have 1 600w hps in a 4x4 veg tent now with now exaust and its stays perfect now but there is no way it will be perfect in 2 more months, i would check bobbles threads and mega yields , they can tell you exactly what you need.

 

[megayields]

hmmmm I'm no expert but I would want a little more on both ends in terms of echanging that air 2 times a minute....but let's wait for peeps like Bobble or DHF or basicly anyone else other than me to chime in...

Sounds like you got good idea's and a good start though, and I like a basement setup, as I have something very similar.

Good luck Benny!

edit; Damn that Josey Whales and Dr. Death, their fingers are quicker than mine!

 

[TheGreenReaper]

I will do the math...assuming 5x5x7 = 175 Cubic feet - textbook says 350cfm to cool each room adequately - or 700cfm total to be safe.

FWIW, I have never had a tent that needed the 2 or 3x air exchange that my rooms do. They just dont hold the heat like the rooms being thinner (I have an older tent that is white inside, it doesnt have the groovy IR reflectix), 1x in a tent has always been enough for me...but every situation is different. My current tent is 6.5 tall and my air exchange is right on the money and as I said earlier, it is running a little cool.

Josey is right...only you know what June 1 looks like where you are.

and megayields...Dr Death..LOL...really? Oh shit that's funny.

 

[Bennyweed1]

Well if I do not heat the basement in the winter or cool it during the summer, it will sit steady at 60-65degrees year round. (maybe drop into the mid 50s during the winter.)

The basement itself is 1000sq ft. All unfinished, all exposed concrete so I think it has the proper sq ft to exchange the heat quickly between all the exposed surfaces....I think.

I will have a total of 1600 watts running in the same basement so I am not sure if the heat dissipation will be where I want it. Total unsure thats why I am asking.

1200w on 12/12
300w on 18/6

 

[TheGreenReaper]

Set up the tents and fire them up with thermometers to see what the result is. It doesn't matter if we tell you its fine or not. Fire it up and see, if it isn't adequate air movement you wont get a great harvest anyway so you will need to 1)have a fluffy harvest 2)find a way to move more air.

The math says it close depending upon ambient temps, and if ambient temps are as you say, w a potential 15-20f differential, I would say you are going to be good - but my opinion means nothing in the vacuum of the internet.

 

[Bennyweed1]

I will do the math...assuming 5x5x7 = 175 Cubic feet - textbook says 350cfm to cool each room adequately - or 700cfm total to be safe.

Thats where I am a little lost also, combined I will have a total 426.5cfm in each tent but it isnt going in one direction. So would I be better canning the intake idea and just add those CFMs to my exhaust fan with a beefier 10in fan?

 

[Hundred Gram Oz]

Keep in mind the heated air will be pushed into a large concrete basement that naturally stays cool year round. Both tents will be housed in the same basement.

Do you always extract into your basement, or do you extract to outside? If the air isn't extracted outside and you don't have a good dehumidifer, expect every window in your house to get condensation, just warning ya bro.

HGO

 

[megayields]

just a feeling I have, don't know if it will help...I just feel you cannot have enough air exchange period. So I always tend to go to the extreme instead of hitting a "specific" mark per se (?)

Clear as mud?

 

[TheGreenReaper]

I never run intake, just exhaust - but that is me and it has always worked great. 10" will be in the neighborhood of 800-1100 cfm, and at the higher end that is likely going to be too much unless put on a thermostat (I am assuming constant "on" with the current discussion) and even then it is liable to pull the sides in 10" each with that much pressure - but I have never said "damnit thats too much air", I make it work, and there are benefits to lots of air exchanging as long as it is warm enough. I would try it with what you have on hand without buying something unless you have to. For sure the 10" would be sufficient.

 

[Grizz]

Set up the tents and fire them up with thermometers to see what the result is. It doesn't matter if we tell you its fine or not. Fire it up and see, if it isn't adequate air movement you wont get a great harvest anyway so you will need to 1)have a fluffy harvest 2)find a way to move more air.

The math says it close depending upon ambient temps, and if ambient temps are as you say, w a potential 15-20f differential, I would say you are going to be good - but my opinion means nothing in the vacuum of the internet.

lol doc death is right, fire them up and see what you need, with temps that cold in the basement you wont need much now and as hgo said be prepaired for condensation, so high humidity will probably be a problem in your tent

 

[Bennyweed1]

lol doc death is right, fire them up and see what you need, with temps that cold in the basement you wont need much now and as hgo said be prepaired for condensation, so high humidity will probably be a problem in your tent

looks like I will have to fire up the energy star rated dehumidifier...dont want no moldy ass nugglets.

 

[megayields]

.....to quote the great Josey Whales........."you gunna pull those pistol's...or just whistle Dixie?"................Let us know how the test run turns out Benny!

Good luck man

 

[bobblehead]

for realz... It's not tough to calculate peeps, but the op has left out the height of the rooms... So I could only do the calculations backward and tell you how much height you have ventilation for... Or something like that...

how about you start of with the dimensions of the grow? From there you can calculate cft, and cfms that need to be exchanged.

 

[Bennyweed1]

for realz... It's not tough to calculate peeps, but the op has left out the height of the rooms... So I could only do the calculations backward and tell you how much height you have ventilation for... Or something like that...

how about you start of with the dimensions of the grow? From there you can calculate cft, and cfms that need to be exchanged.

Each tent is 162.5cuft. @ 280cfm exhaust puts me around 1.71 exchange a minute.

5x5x6.5(tent)

 

[Bennyweed1]

So does having a intake fan matter? Will the 146.5cfm being pushed in add to the CFM exchange rate or should I say screw that idea and leave it to be passive?

 

[bobblehead]

The thing about having all your cfm in either exhaust or intake, is that it's limited by how fast the air can move through the grow space. You can have a supercharged exhaust, but if there isn't enough air coming in the tent to pass through the fan, it won't make a difference.

You should be able to use passive intakes to prevent a bottleneck... personally I exchange my air 2x a minute, 2 435cfm fans, one for intake, one for exhaust. There's no question about my air exchange, and my temps stay within 10F of ambient with 1800w of light.

 

[catman]

Are you going to use an odor scrubber? If not and you already have those fans and don't want to make any more purchases, it be worth a shot running each fan as an exhaust only. I estimate my fan is moving about 300CFM through a scrubber with a 600w in a 4x4 and 70F ambient keeps me at 75F in the tent.

Intake fans should not be needed and I don't think splitting is the route you want to go. Run the least ducting (none if possible) and avoid making curves. Air flow is greatly reduced by resistance with lower powered-high speed fans like the S&P models. Having both an intake and exhaust fans makes the fans work against each other which creates heats and lessens the life time of the motors. One of each might not be an issue depending on a particular case, but a failed fan is no good. I'd rather cut a tent some bigger intake holes myself than run an intake fan.

With only a 600w in a 5x5, you will have lots of space and you won't want to grow your plants 6ft tall. So, you want a fan below the bulb which keeps the heat pinned to the ceiling, but if you blow too much air up, you just mix the heat around everywhere.