I have a 6” 240 cfm exhaust fan for a 5x5x6 room. It doesn’t really seem to be enough to pull out heat buildup from the lights. I run it only 2 mins on 7 mins off to help maintain humidity level. Access to replace would be a big pia. Would adding another 240 cfm fan further along the exhaust line boost exhaust to approx 480 cfm?
Inline booster fan
- Thread starter MFMc
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ROSTERMAN
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I use one of these in approx 10 x 10 x 8
https://www.amazon.com/Hydrofarm-AC...words=fan+vortex+6+inch&qid=1621256249&sr=8-3
I had an infinity 6" fan and vent on 4 x 4 with 600 watt HPS. I think it is rated around 400 cfm, still to hot. 8" Infinity flows about double...with the 6" on intake I can run venting as long as it takes to cooler air, and 8" to exhaust the warm air to carbon filter and then outside.
Get the 8" fan for exhaust and use smaller one to bring in cool air. If your exhaust goes into the room with the grow chamber, re heating the air and cycling it around will of course cause heat to keep going up.
The 8" version is so much stronger than the 6" version it is ridiculous.
Bubba
Get the 8" fan for exhaust and use smaller one to bring in cool air. If your exhaust goes into the room with the grow chamber, re heating the air and cycling it around will of course cause heat to keep going up.
The 8" version is so much stronger than the 6" version it is ridiculous.
Bubba
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You have 150 cf of space to vent. Every 24 seconds you moved the air in your tent. I would recommend filtering your make up air and lower your fan rpm so the light doesn't have a chance to build up heat.
Not following on how lowering fan rpm is going to help fan from not allowing light to heat up? mine gets more hot with lower rpm, less hot when flow is increased...maybe I'm missing something, highly likely...
Bubba
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Easy installation and it works great. Real test will be to see how long it lasts.
Mine is brand new as well. The previous 6 inch is about 1 year. That is I have had it one year it still works fine. I didn't mean it only lasted one year.
Bubba
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Sorry it took this long to get back to you, my laptop broke. Getting another 240 cfm fan in a 150 cf space when you cycle your original 240 cfm fan 2 min on 7min off seems overkill to me. One fan should pull the air in your tent, lower the speed and keep the fan on, should work.
LabRat
Active Member
Putting the same size fan inline with the other won't increase the output one bit unless there is a carbon filter on the intake. Then you would have some increase in output as the two fans would have more power to suck air thru the filter but still probably wouldn't even hit the output of one fan with no filter.
Pretty sure the OP was talking about one of those duct booster fans and not a real inline 6" as I've never seen one of those push under 400cfm. But even two real 6" inline fans won't increase the output alone as they are both spinning at the same speed. Hook them up to a variac and increase the input power to make them spin faster would move more air but probably fry the fans much sooner than usual.
Old thread.
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Increase the pipe size?Putting the same size fan inline with the other won't increase the output one bit unless there is a carbon filter on the intake. Then you would have some increase in output as the two fans would have more power to suck air thru the filter but still probably wouldn't even hit the output of one fan with no filter.
Pretty sure the OP was talking about one of those duct booster fans and not a real inline 6" as I've never seen one of those push under 400cfm. But even two real 6" inline fans won't increase the output alone as they are both spinning at the same speed. Hook them up to a variac and increase the input power to make them spin faster would move more air but probably fry the fans much sooner than usual.
Old thread.
LabRat
Active Member
Increasing the pipe size would reduce restrictions a bit so a modest increase in output should result but maybe 10 -20% at most. The only way to double the output from using those two fans would be to have another exhaust line and outlet for the 2nd fan. Better to just buy a real 6" inline fan that has 400 - 440cfm output and use the existing exhaust line.
That's what I have in my 7x9x6.5'h grow room is a no-name 6" I've been expecting to die for the last 5 years and bought an 8" Vivosun one for a replacement as I had plans to double my grow space but won't be doing that now and the 6" is still pushing enough air outside and shows no further signs of crapping out on me. I run that fan at half speed on a temp/rh controller so it only runs when ordered to do so. Makes a rattling sound as it slows down when it shuts off but seems fine while running. I took it apart for cleaning and maybe put a couple drops of 3-in-1 electric motor oil on the bearings but they're sealed so no access to them.
By no-name I mean there are no markings whatsoever on the fan inside or out. No power plate either to tell you wattage etc. I hooked up my Kill-A-Watt meter and marked on my speed dial where the wattage used was 60 instead of 120 to judge half speed. Whether that means the fan is running at half the RPMs I don't know but it's a lot slower than full blast tho the noise is not a concern. Brings in cool air slower that way so there's less temp swing.
Think of it this way. If your unicycle and your bicycle have the same size wheels does the bike go twice as fast when the wheels spin at the same RPM? Nope. Same thing with the fans.
