Push or Pull through hood

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Edgar9

Well-Known Member
I've always pulled through an air cooled hood b/c that seem to be the logical thing to do. Recently a guy at a hydro store said I should be pushing through the hood with an inline fan b/c it saves the fan's motor since you're not exposing it to hot/warm air. Another guy at a different hydro store said alway pull through the hood for best results.

Personally I think pulling is better and the fan's are designed to handle the heat.

Any opinions?
 
prosperian

prosperian

Well-Known Member
Here is a good reference article on fans. click here

Although this topic has been discussed several times on this forum, it's my opinion that the heat generated from light fixtures is nowhere near the fault levels of the sealed bearings and other fan parts. Space restrictions of the grow room is the biggest factor in deciding which configuration is best for you. I pull air through my system because I don't have the space for a in-line fan and carbon scrubber in my grow closet. Most in-line fan manufacturers will tell you that the fan can be used to pull or push air with no difference in performance. Do what's best for you in this case.
 
hotrodharley

hotrodharley

Well-Known Member
Edgar9 said:
I've always pulled through an air cooled hood b/c that seem to be the logical thing to do. Recently a guy at a hydro store said I should be pushing through the hood with an inline fan b/c it saves the fan's motor since you're not exposing it to hot/warm air. Another guy at a different hydro store said alway pull through the hood for best results.

Personally I think pulling is better and the fan's are designed to handle the heat.

Any opinions?
Click to expand...
You have written proof by the fan manufacturer that states this fan is heat proof? Regardless, fans are made to PUSH air and not pull it. Period. Heat and vibration are the culprits in mechanical failures. Let's invite that by pulling heated air through the fan chamber.

Now WHY anyone would do it is beyond me. Just because it can be done? Because their buddy's best friends buddy does it? Just name one GOOD reason to pull heated air through a fan when it cool air can be pushed.
 
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joe macclennan

Well-Known Member
Pushing air through can cause your hoods to leak too. I had to double the seals on my xxls to prevent them from leaking. Pulling air through makes em seal tighter. Another factor to consider would be noise. The farther away from the exit or inlet the more quiet it will be. As far as heat destroying the fan. No this won't be a problem. In fact the heat from the hoods will help to evaporate any condensation from the cool outside air before it hits the fan.
 
hotrodharley

hotrodharley

Well-Known Member
Actually these things called "clamps" are what secure lines to flanges. Not air pressure sucking it down. When experienced adults assemble stuff that is. Duct tape works well too.
 
hotrodharley

hotrodharley

Well-Known Member
Please name the brands of fans you are buying to pull heated air with so I can invest in those companies. Seriously. Repeat sales are what keeps businesses alive and thriving.
 
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joe macclennan

Well-Known Member
100-115 degree air will not reduce the life of a solid fan by any amt. of time. If your air is any hotter than this you should move more air. The air on my outlet runs tween 90-105. I check it w/ an infra-red thermometer.
 
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joe macclennan

Well-Known Member
hotrodharley said:
Actually these things called "clamps" are what secure lines to flanges. Not air pressure sucking it down. When experienced adults assemble stuff that is. Duct tape works well too.
Click to expand...
Wow, it seems you are becoming a dick since losing your job. I may regret offering my condolences on this subject. You have been dickish in a few threads of late.
I was talking about the hood seals jerk. Not the duct ends. If you had taken the time to read my post instead of deliberately looking for holes in it you would know this.
I do Hvac for a living jackass. I do not care how much you think you know on this subject. Dealing w/sealing duct and fan life and air flow is old hat for me.
 
hotrodharley

hotrodharley

Well-Known Member
joe macclennan said:
100-115 degree air will not reduce the life of a solid fan by any amt. of time. If your air is any hotter than this you should move more air. The air on my outlet runs tween 90-105. I check it w/ an infra-red thermometer.
Click to expand...
Sounds good. All you inexperienced growers out there do like this fellow.
 
prosperian

prosperian

Well-Known Member
I named several reason above to pull air instead of push and in my opinion all valid. Space limitations, stealth, noise, to name a few. The fan bearings can support heat in excess of 400 degrees as well as the other fan components. This is a silly discussion as were the other threads on the same pull vs. push.
 
prosperian

prosperian

Well-Known Member
Hotrod is a cool dude with a lot of experience. i value his opinion, but in this case, I politely disagree.
 
dopedeeii

dopedeeii

Well-Known Member
Its works for me to pull air thru My Hood hot air raises and I blow on cold from the bottom it evens out me temps and humitity I have a lot of moist air where I live so I would be worried about blowing a bulb because of the h2o in the air
 
B166ER420

B166ER420

Well-Known Member
Pulling air thru with a fan inside the grow area creating positive air pressure works best....my 2 cents..lol
 
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thinn

Well-Known Member
Does it really matter? There really is no proof or any study that i have seen to prove either or is better, i say do it how you like. All Equipment will fail and you should have the dough to replace any of it as soon as it does. I pull air thru my filter and push thru the hood in the same line.
 
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