Considering a redesign of my ventilation

Homegrown4203

Homegrown4203

Active Member
Currently I have my ventilation setup as follows. Carbon Filter -> 435 CFM 6" Fan -> Out of Tent -> Up into attic AND 6" duct fan (165 cfm) -> 400w HPS cooltube -> Out of tent -> attic.Considering the amount of equipment I'm running, I would've thought that I would surely see a better temperature result than I do. Typically the temperature at the canopy 12" below the light is approx. 7 degrees higher than the temperature of the room. The tube feels fairly hot to the touch and I believe its because my duct fan isn't powerful enough to push the distance up into the attic efficiently.Now I've already dumped a boatload of money into this setup and would rather not dump much more. Would adding another duct fan be a good solution here? Or should I just run my exhaust through the cooltube as I KNOW that fan is strong enough to vent it.
 
Homegrown4203

Homegrown4203

Active Member
I think I'm just going to add another 6" air booster fan. The one's from airboosterfans.com have 240 free air cfms. So between that one and the one from HTGSupply I should have about 400 cfm cooling the light. I'm going to have one blowing the air in and the other sucking it out. so it'll go cool air -> fan -> light -> fan -> attic.Sound good?
 
kno

kno

Active Member
You have one 400w light to cool?
I cool my 400w with a 4" 80CFM duct booster fan. The room temps will be higher because of the light but my small closet never gets over 82f
Maybe the filter on the fan is slowing it down?
 
Homegrown4203

Homegrown4203

Active Member
kno said:
You have one 400w light to cool?
I cool my 400w with a 4" 80CFM duct booster fan. The room temps will be higher because of the light but my small closet never gets over 82f
Maybe the filter on the fan is slowing it down?
Click to expand...
Yes I have a 400w HPS. There is no filter attached to the cool-tube fan. Its just cool air being pushed across my 4 foot tent across the light and up about 6 feet or so into the attic. Its a 160cfm fan and I think it just has too much of a distance to travel so it doesn't do that effective of a job.My temps stay about 6-7 degrees warmer than the a/c'd room its in, and I'd like to cut that down to 3-4 and considering my exhaust fan is exhausting my 4x2x5 tent 11x per minute I believe its all in the efficiency of the cooltube at this point. I'm hoping that by adding a 240cfm free air duct fan (this will also increase the efficiency of my other fan because it will be in-line with it, the combined over 400 cfm will be enough to sufficiently move all of the heat from the cooltube out into the attic.
 
mcone

mcone

Active Member
I am having a similar issue with my 600w in my 4.5 foot tent...
temps are 10degrees hotter inside than out.... I will stay posted to see if you get a good result from increasing your air-cooling cfm as opposed to increasing radiant exhaust cfm.

Homegrown4203 said:
Yes I have a 400w HPS. There is no filter attached to the cool-tube fan. Its just cool air being pushed across my 4 foot tent across the light and up about 6 feet or so into the attic. Its a 160cfm fan and I think it just has too much of a distance to travel so it doesn't do that effective of a job.My temps stay about 6-7 degrees warmer than the a/c'd room its in, and I'd like to cut that down to 3-4 and considering my exhaust fan is exhausting my 4x2x5 tent 11x per minute I believe its all in the efficiency of the cooltube at this point. I'm hoping that by adding a 240cfm free air duct fan (this will also increase the efficiency of my other fan because it will be in-line with it, the combined over 400 cfm will be enough to sufficiently move all of the heat from the cooltube out into the attic.
Click to expand...
 
Homegrown4203

Homegrown4203

Active Member
mcone said:
I am having a similar issue with my 600w in my 4.5 foot tent...
temps are 10degrees hotter inside than out.... I will stay posted to see if you get a good result from increasing your air-cooling cfm as opposed to increasing radiant exhaust cfm.
Click to expand...
I just ordered another 6" duct fan. It is a 240cfm (free air) duct fan. I plan on running the 240cfm fan -> cooltube -> 160cfm fan -> attic

I'm hoping this is enough to drop my temps a couple degrees by effectively cooling the light.

Will keep you posted on how it goes.
 
8'cube

8'cube

Member
Homegrown4203 said:
I just ordered another 6" duct fan. It is a 240cfm (free air) duct fan. I plan on running the 240cfm fan -> cooltube -> 160cfm fan -> attic

I'm hoping this is enough to drop my temps a couple degrees by effectively cooling the light.

Will keep you posted on how it goes.
Click to expand...


You should run your exaust through your light. The duct booster fans are OK but dont do very good if the duct is very long.
 
DubsFan

DubsFan

Well-Known Member
Homegrown4203 said:
Currently I have my ventilation setup as follows. Carbon Filter -> 435 CFM 6" Fan -> Out of Tent -> Up into attic AND 6" duct fan (165 cfm) -> 400w HPS cooltube -> Out of tent -> attic.Considering the amount of equipment I'm running, I would've thought that I would surely see a better temperature result than I do. Typically the temperature at the canopy 12" below the light is approx. 7 degrees higher than the temperature of the room. The tube feels fairly hot to the touch and I believe its because my duct fan isn't powerful enough to push the distance up into the attic efficiently.Now I've already dumped a boatload of money into this setup and would rather not dump much more. Would adding another duct fan be a good solution here? Or should I just run my exhaust through the cooltube as I KNOW that fan is strong enough to vent it.
Click to expand...
That 435cfm fan...it should be at the end of your ducting sucking air out, not pushing air out of your tent. Put that fan at the end of your ducting for exhaust. Think Suck, not Blow.

Edit, what is the total length of ducting you are trying to cool, including the length of the light and all the way out the wall.
 
A

astvadlut

Member
I accept: The one's from airboosterfans.com have 240 free air cfms.In Carbon Filter -> 435 CFM 6" Fan -> Out of Tent -> Up into attic AND 6" duct fan (165 cfm) -> 400w HPS cooltube -> Out of tent -> attic. Typically the temperature at the canopy 12" below the light is approx. 7 degrees higher than the temperature of the room.
 
Homegrown4203

Homegrown4203

Active Member
DubsFan said:
That 435cfm fan...it should be at the end of your ducting sucking air out, not pushing air out of your tent. Put that fan at the end of your ducting for exhaust. Think Suck, not Blow.

Edit, what is the total length of ducting you are trying to cool, including the length of the light and all the way out the wall.
Click to expand...
I'm not sure I understand what you're saying here? The fan is sucking air out of the tent and then pushing it into the attic. What does it matter where the fan is along that line as long as the sucking end of the ducting is in the tent and the venting is in another room (attic).
Total length of the ducting including the cooltube is probably about 11 feet. Thats the entire distance from pulling cool air from outside of the tent, across the light, and then out of the tent and up into the attic
You should run your exaust through your light. The duct booster fans are OK but dont do very good if the duct is very long.
Click to expand...
Thank you for your input, I tried running the exhaust through the light but temps went up a smidge and I think it has to do with the fact that warmer air is being pulled across the light instead of the cool air outside the tent. I'm hoping my extra duct booster fan will do the trick
 
DubsFan

DubsFan

Well-Known Member
I would have the fan at the very end of your ducting. It may be sucking air out of your tent but then it's pushing up the rest of the ducting. Put the fan at the very end of the ducting so it's sucking out the entire line of hair.

Your fan should not push any air at all, just sucking. Put the fan in the attic at the end of your ducting.

Yes it matters. A booster fan will not be needed if you put your fan where it should be, at the very end of your ducting. Suck, not blow. It's that simple.
 
mcone

mcone

Active Member
I was just going to post this... Beat me to it, nice work. Yes it matters, plus the fans actually generate heat as well, so moving it into the attic moves the heat source further away from the tent. Same with the ballast, as far outside and away as possible.. IMVHO.

DubsFan said:
I would have the fan at the very end of your ducting. It may be sucking air out of your tent but then it's pushing up the rest of the ducting. Put the fan at the very end of the ducting so it's sucking out the entire line of hair.

Your fan should not push any air at all, just sucking. Put the fan in the attic at the end of your ducting.

Yes it matters. A booster fan will not be needed if you put your fan where it should be, at the very end of your ducting. Suck, not blow. It's that simple.
Click to expand...
 
Homegrown4203

Homegrown4203

Active Member
mcone said:
I was just going to post this... Beat me to it, nice work. Yes it matters, plus the fans actually generate heat as well, so moving it into the attic moves the heat source further away from the tent. Same with the ballast, as far outside and away as possible.. IMVHO.
Click to expand...
Thank you both! I will have to see about what I can do with moving this fan! It will also help with the amount of space within my tent if I can move it.

I had no idea it made a difference, but it makes sense.
 
DubsFan

DubsFan

Well-Known Member
Homegrown4203 said:
Here's a pic of the setup as it stands
Click to expand...
I have the same fan it can suck your balls off through 15ft of ducting. But it shouldn't be in the tent. It should be at the end of that exhaust tube that is going up.

I know I sound redundant...but that fan is pushing more than sucking. Once mounted at the very end of the ducting it will be sucking 100% of the ducting. You still may need AC.
 
DubsFan

DubsFan

Well-Known Member
Yo. Here is what I did. Fresh air intake on the far left and it is all being sucked out on the far wall to the right. Zero pushing all sucking...sounds sexual doesn't it? Cause it is. :)
 

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