How to ventilate a LED grow ?

[manitu]

How do you people ventilate your LED grows?

I guess the usual way , to extract the air from above the lamps doesn't cut it..

I'm thinking of putting the outlet at the coldest point , like on the floor , and the intake above the lamps. With decent air circulation in the box , this should work fine

What do you think?

.manitu

 

[LEDGirl]

If you run into issues with heat (say 90 degrees or above) then the method you mentioned would likely be the best to cool your area.

 

[manitu]

To clarify , I meant to extract the coldest possible air out of the box , to prevent the heat to escape. And maybe put the fresh air intake above the lamps to heat it up a bit.
kind of the oposite of a HPS grow.

.manitu

 

[unclefishstick]

maybe a small intake fan and passive exhaust to keep fresh air coming in,but letting the air pressure push the old air out through a carbon filter passively.

 

[manitu]

maybe a small intake fan and passive exhaust to keep fresh air coming in,but letting the air pressure push the old air out through a carbon filter passively.

Would only work in a completely sealed room.
If odor is an issue , allways keep your growspace under negative pressure , evacuating trough a carbon scrubber.

.manitu

 

[unclefishstick]

ah,but thats for an old style system,it would have to be well sealed,but since the plants grow more efficiently at a higher temp than a standard garden,maybe reversing the typical filter config is a good strategy.really just sealing it and adding co2 is the best route,just need a fan to keep the air moving in a basic tent set up then.

just my two cents anyway...

 

[HHHG]

How do you people ventilate your LED grows?

I guess the usual way , to extract the air from above the lamps doesn't cut it..

I'm thinking of putting the outlet at the coldest point , like on the floor , and the intake above the lamps. With decent air circulation in the box , this should work fine

What do you think?

.manitu

I think you have it backwards - the intake goes at the bottom (cold) and exhaust goes at the top (hot).

 

[manitu]

I think you have it backwards - the intake goes at the bottom (cold) and exhaust goes at the top (hot).

I know..
My question was if ventilating the oposite way will provide decent ventilation , or if the fresh air will drop to the floor , and go right out again.. But I see that retaining heat while supplying fresh air is a difficult task..

But here's another idea , how about a heat exchanger?? Those rotating heat-exchangers made of aluminum would recycle 80% of the heat.

.manitu

 

[MeanBean]

Just flip your design, vent it in the proper direction. Fresh air is important, it will flow easier this way. If you need some heat Slap some UV Ray CFL's in there.

 

[unclefishstick]

Just flip your design, vent it in the proper direction. Fresh air is important, it will flow easier this way. If you need some heat Slap some UV Ray CFL's in there.

That was what I was trying to get across.In a typical HID lit room you would exhaust the hot air from the upper area of the garden and bring fresh air from the cooler lower area in a passive fashion to create a negative pressure inside the garden.So with the LEDs,perhaps creating a positive pressure in the grow area would allow the "stale" air to be pushed through a filter passively while allowing the air inside to remain at a high enough temp to take advantage of the increased plant growth.Just my speculation,MeanBean has actual experience with the lights.

 

[MeanBean]

It's 4 times easier for a fan to suck air out of a sealed box then to push it in.

Plus heat rises. You want to intake from below the canopy. As the heat rises it will pass your plants letting them get a breath of fresh air, then its past the lights and out.

I would imagine even if you beefed up you fan, and pushed the air in from the top the air flow would be sloppy. and mixed with the rising hot air..

 

[Zombo]

Makes sense to me -- probably the approach I'll take with a cabinet for my LEDs. +rep unclefishstick (awesome username and location).

 

[MeanBean]

Also the air intakes on a plant are on the bottom of the leafes, if your pushing air down your kinda hitting the wrong surface ya know?? Not saying it can't be done, if you try it I hope it works! Just another great tool for us stealth growers!

 

[manitu]

I guess I agree.. for a small growspace , growing MJ, a heater is the solution.

I'm interested in personal MJ growing , but I'm also looking at options for 300 sq.feet, growing vegetables and spices. Using heaters constant to keep the temps up is not an option.
It looks like a heat exchanger system is the best option here.
.manitu

 

[MeanBean]

Vegtables and spices need way less intense light, I wonder just how sweet a tomato plant a 126er could grow.