Noobie ventilation questions/concerned - first grow

I'm setting my first grow up this week and I can't help but worry about how I'm going to map/install ventilation in my room. I have two 600W lamps with air-cooled reflectors (6" holes on each side). I plan on ordering a can-filter with a 6" flange, possibly a 6" horti-control dust shroom, and a 500cfm 6" exhaust fan - all from bghydro (Could anyone provide some input on this retailer as well?).

Despite reading numerous pages of forum posts, guides, books, etc, I can't quite figure out how I'm going to route everything/where to have fans pull or push from etc..

At this particular moment in time I plan to have a passive intake, two 6" holes with mesh or some type of filter, directly to the outside. Can I put the dust shroom on the duct flanges I install on my intake?

and then diagonally from that, my setup would be: 600W-> 600W -> can filter -> exhaust (500cfm fan pulling heat/air through lights and up & out of room.) Would that suffice? I'm worried that I will either cool the lights sufficiently but not circulate air, or circulate air and not cool the lights. Also, can I put the shroom filter on the intake of my lights?

I guess I'm just confused because I have the two lights as opposed to one light. Any help/comments/advice would be greatly appreciated.

Perhaps I could have my exhaust just be in the upper corner of my room: canfilter -> exhaust fan up and out of room
and then a separate line for cooling the lights that runs through the room with an exhaust fan on the outside pulling air through: dust shroom -> light 1 -> light 2 -> exhaust fan outside of room pulling it all through?

It is best to have 2 fans, one for the carbon scrubber and one for the lights. The reason you want 2 is because you want to use only one for the lights as from light to carbon scrubber is no good for the reason that it will heat up the carbon and cut the life in less than half. By seperating the two you can prolong the use of your expensive scrubber and also you will have much better cooling of the lights when the air has not as much resistance. Passive intake is great. Hope this helps!

WP

I think I understand. So two exhausts as well? (One for the scrubber, and one for the lights?) Do I want to pull the air through the light or push? Is it okay to put both of the fans on the outside of the wall to pull both lines through?

If you can, you want to create two separate systems. One to cool the lights and another to get rid of smell and keep the room circulating.

Set up 1:
1 intake and 1 exhaust with the two 600 W and a fan

Set up 2;
I intake (passive) and one exhaust with another fan and a carbon filter

shroom cloud goes on the intake to filter the air so your lights dont get dirty

Just pull the heat from the lights.

For the sake of clarification: My air exchange ventilation circuit will be... passive intake holes -> exhaust with fan pulling through carbon filter

and to cool my lights: shroom filter -> light 1 -> light 2 -> fan pulling through -> exhaust up and through roof

I appreciate the help so far, I think I got the hang of it.

the intake for the cooling circuit being the hole on the first light in the series?

thomashankle said:

I think I understand. So two exhausts as well? (One for the scrubber, and one for the lights?) Do I want to pull the air through the light or push? Is it okay to put both of the fans on the outside of the wall to pull both lines through?

Click to expand...

Yes, I believe two exhausts would be best. They can both exit the same way though. Also, with two fans if you push the air through the lights then if there are any leaks it won't cause smell problems. If you pull the air through the lights then if there are any leaks it will suck in some air from the room and out the exhaust by-passing the carbon scrubber. This could cause smell issue's.

WP

I also wanted to add, if you want to just make it simple and are not using more than two air cooled hoods then you could have the carbon scrubber in the room attached with vent pipe to the lights and then to the fan and out the room. This way you will be sucking from the carbon scrubber and then the clean air through the lights and out the room. The carbon scrubber will create resistance and cause a vacuum effect inside the lights causing air to enter into them making smell excape so you have to make sure the lights and entire system is sealed correctly. I use the smoke test to see if there are any suction leaks.

So with the two above posts you have two options. Obviously the first is most efficient for a larger grow but the second doesn't require two fans and can work quite effectively if you seal well.

WP

thomashankle said:

the intake for the cooling circuit being the hole on the first light in the series?

Click to expand...

No, the intake for the lights should be outside the room so that you do not suck non-scrubbed air out of the room.

This is the best way to setup your room.


Create a 6 inch intake and exhaust for your air cooled lights. Maybe in your ceiling, into your attic. Try to keep the intake and exhaust directed away from each other because ideally, you want cold air coming in.


Because there are small cracks in the ducting and light fixtures, this will create a slight odor problem. You have a few different ways to filter the air for the air cooled fixtures.


1. push the air into a can filter
2. create a filter box and pull air through the box.
3. put your fan at the start of your ducting run and push through the lights and finally into a can filter. I don't like this option because you can potentially create a positive pressure environment in your room.


I would go with option 2...this is a pretty decent sized project, so get ready to build something.


Now that your lights are properly air cooled, you move on to cooling your room.


You get a can filter and appropriate sized fan. You should size your fan to completely exhaust your room within 3-5 minutes. Your filter is where your ducting starts, then the fan, then outside. Your fan must be controlled by an environmental controller like the CAP AIR1...which activates your fan if your room hits a certain temp or humidity.


You can do everything with 1 filter and fan, but your room will vent much more frequently. And if you do it with 1 filter and fan, it will not be 100% odor proof. There are small cracks in your light fixtures and ducting...unless you push all of your air into a can filter. You could put your can filter in your attic, but it's really heavy so good luck.


Run your room at night.

500cfm is plenty for 2 600w lights, and i would even use it to pull air through my filter and push the air through the lights, with that much cfm you should have no problem but it would be more effecient to have a seperate blower for the scrubber and heat is always dealt with better by pulling instead of pushing but if you did it the way i described first you shouldent have any problem. i am cooling a 600 and a 400 with a 190 cfm fan thats pulling through a filter and pushing the heat and its doing just fine so i think you shouldent have any problems.