questions ??

[Bhappy324]

If I set up a very small greenhouse that has built in air escaping "Windows" in a completely empty and open room with two outside Windows to allow cool air to come in and I'm running a 600w mh/his bulbs do I need to run a inline fan to cool the vent hood? I have oscillating fans running in greenhouse but no ventilation other than the two Windows built into the greenhouse I just do not want to build to much heat and burst bulb. Or am I safe because of greenhouse Windows and outside Windows????
Any thoughts advice or comments would be appreciated

 

[zem]

well, it's not bursting the bulbs that you should be worried about but poor plant growth with low venting and/or high heat buildup. you will need to exhaust actively intake passively, so get an exhaust fan, the centrifugal type, and vent that space

 

[The Hemp Goddess]

First why would one use a green house indoors? Indoors, you need something that you can keep light tight, like a tent. A greenhouse will allow light to disburse throughout the entire room--it is uselesxs to put a greenhouse in an indoors pace--no advantage at all and I am confused by its use??????

Yes, you need an exhaust fan, regardless of the number of windows. Passive ventilation will not work. Oscillating fans just move air around--you actually need to exchange air. Ventilation is for more than heat control--plants need a continual supply of fresh air all the time the light are on for proper photosynthesis. If the heat gets high enough to cause the bulb to explode, it is far too hot for plants and they would be dead.

What type and size of light are you using in how much space?

 

[Locked]

Ditch the greenhouse for a tent and like THG said, you will need an inline fan for ventilation.

 

[Bhappy324]

I haven't used it yet I got it for free and was going to put reflective material on inside to form a poor man's tent ... It would be 3x4 600w hps/mh.yoo

 

[Kraven]

This is what you need. It is less than $150 USD most places. 39"x39"x71" w/ a 400w light. I could go to a 600w, but have been happy w/ 400w a very long time.

 

[Kraven]

This is what you need. It is less than $150 USD most places. 39"x39"x71" w/ a 400w light. I could go to a 600w, but have been happy w/ 400w a very long time.

I use a 6" inline fan, it exchanges the air 3 times a MINUTE in that room.

 

[Bhappy324]

Ok thank you all very much I will go online and get myself a tent

 

[The Hemp Goddess]

I would go with a 4 x 4 tent as you have a 600w light. Also, down the road, should you decide to run T5s fluoros for vegging, 4' tubes will fit in there.

 

[Bhappy324]

If I use the. 4 foot t5 flouros in my 4x4 tent will just one fixture be enough for vegging??

 

[Locked]

If I use the. 4 foot t5 flouros in my 4x4 tent will just one fixture be enough for vegging??

No it won't unless you partition off at least half the tent. If you have to Veg in the same tent you are going to Flower in then you are best off using half the tent and when you switch to flower the whole tent with at least a 600W HPS. I say at least because I have a 4x4 Flower tent and at first tried only a 600W. It didn't quite cut it and the plants on the outer edge paid for it. They yielded way less and were nowhere near as nice and full as the plants directly under the light. The second time around I added a 400W HPS to it and the yield went up big time. I honestly would recommend at least a thousand watts of HPS Min and two 600W HPS in air cooled hoods will kill it all day everyday. JMO.

 

[Surfer Joe]

Ventilation is for more than heat control--plants need a continual supply of fresh air all the time the light are on for proper photosynthesis.

Are you saying that the fans and extractors should be turned off when the lights are off?
I thought that you kept them on all the time.
I have been keeping the oscillating fans and the extractor fan on all the time.
Is it better for what the plants do in the dark to keep the fans going or to give them a period of still air?
Being able to turn the extraction fan off when the lights are off may help keep the temps from getting too low when the lights are off for me.

 

[The Hemp Goddess]

No, sorry, that is kind of confusing...that is not what I am saying. There are other reasons for keeping your fans running 24 hours. I just want people to know that there are multiple reasons for running fans--it is not just about heat control.