Push or Pull through hood

This burnt out bearing talk scares me. I guess I'll be pushing.

https://www.youtube.com/watch?v=YleXlgHI1oM

I do neither b/c I'm a cheap bastard and I love natural ventilation - however; amongst other crowds, I've only heard the suggestion to "pull" air, and that seems to be the general consensus

lol @ edgar

Professorpotsnob do you mean the cheap duct booster such as the bathroom extractors dude ? Peace

Ok let me answer your questions on these types of fans, first off they were not designed to cool your light ,this is childs play to the fans capability, These fans are made for the purpose of exhausting Stove range hoods , and not grandmas stove ,were talking Wolf/garland/ Viking ect. 6-8-10 burner stoves and often with BBQ char centers, They were made to take Heat/Smoke/Grease. they are built to with stand some harsh conditions , that why they are made out of heavy duty material, do you think they skimped on the bearings DONT THINK SOO, So why are some of you having bearing falure. it not wether your pushing or pulling, ITs because YOU are ALL guilty Of starving your fan for AIR, A light with 6'' Collars Does not require a 6'' 400 cfm Fan, 6'' duct work cant handle 400 cfm , 6'' duct work at its best can only hand 150 cfm, 400 cfm requires about 9'' in round type duct work ,but 9'' is not easy to find these days soo you go with 10'' . Now does your light need that 6 inch fan to cool that light ,Hell no ,the light manufacture put those 6'' round collars for a reason ,because only 150 cfm is needed, if ducted correctly it will remove /EXHAUST (PULL) Not Push, So you went way overboard on your fan , why because the fucken HYDRO Store Dont know jack shit about moving air and the bigger fan he can sell you the more profit he makes. Granted I am a new grower and noo jack shit about growing , but I made my own hood 24'' L X 16'' W X 8'' H half moon shape 400w MH horizontal bulb 3

So my reflector hood that I made is open type half round designed 400w mh with a 30 cfm fan about 3''x3'' mounted above the mogul base (over the bulb) so at any point the reflector hood is only 4'' away from the bulb. a full on 400w mh bulb get to about 380+ deg F with out the little 30 cfm fan on the hood reaches 380deg f in 10 min, with the fan on the temp gets only 4 degrees above my room temp ,witch is a 32'' x 36'' Closet ,it sealed very well except for a 10''x 10'' exhaust grill in the ceiling and a 12''x12'' grill low on the wall to provide air exchange in to the grow room temp range 68f- 79f , I keep the light about 18 inches from the grow ,the top of the canopy is alway the same as room temp. So why can I use a 30 cfm fan to cool my lite and you guys need 400 cfm and a fully hermetic reflector, Explan this to me??? LOL , Soo here is the deal 3 thing make this happen 1st efficently installed exhaust that can properly obtain the rite amount of air exchange , 2d thing is design half round reflector hood 30 cfm fan properly placed in reflector , when a fan throws the air it is traveling in a spiral motion the half round open reflector enhances the movement with the same conforming shape Round ,intern the air moves very easly acrross the reflector and bulb ,3d when the air hits the end of the 24'' reflector it get suck up to the exhaust, again hot air rises so no hinder in air movement.

jrainman said:

So my reflector hood that I made is open type half round designed 400w mh with a 30 cfm fan about 3''x3'' mounted above the mogul base (over the bulb) so at any point the reflector hood is only 4'' away from the bulb. a full on 400w mh bulb get to about 380+ deg F with out the little 30 cfm fan on the hood reaches 380deg f in 10 min, with the fan on the temp gets only 4 degrees above my room temp ,witch is a 32'' x 36'' Closet ,it sealed very well except for a 10''x 10'' exhaust grill in the ceiling and a 12''x12'' grill low on the wall to provide air exchange in to the grow room temp range 68f- 79f , I keep the light about 18 inches from the grow ,the top of the canopy is alway the same as room temp. So why can I use a 30 cfm fan to cool my lite and you guys need 400 cfm and a fully hermetic reflector, Explan this to me??? LOL , Soo here is the deal 3 thing make this happen 1st efficently installed exhaust that can properly obtain the rite amount of air exchange , 2d thing is design half round reflector hood 30 cfm fan properly placed in reflector , when a fan throws the air it is traveling in a spiral motion the half round open reflector enhances the movement with the same conforming shape Round ,intern the air moves very easly acrross the reflector and bulb ,3d when the air hits the end of the 24'' reflector it get suck up to the exhaust, again hot air rises so no hinder in air movement.

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Pictures of your setup? Do you have a degree in fluid mechanics or did you just make all of that up on your own?

mr2shim said:

Pictures of your setup? Do you have a degree in fluid mechanics or did you just make all of that up on your own?

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I doubt any of you have degrees, and even if you did, none of ya'll opinion are based in fact; ya'll are mostly speculating.... Both ways seem to work, and it's seem to be a personal preference. Ya'll are wasting your time trying to convert one another and or prove one another wrong when NONE of you really possess the expertise or have the scientifically tested data to prove that the other is wrong.... Which is why this will continue to be an endless and pointless battle that will span another 7 pages with the same conclusion... My way is right, and their way is wrong.

hotrodharley said:

Otherwise I tend to try to save my money by not abusing my gear. Pot growing gear, motorcycle tools, carpenter's tools - whatever. I take care of it and it takes care of me.

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hotrod, they didn't have electricity when you first started growing. Didn't you use a hamster in a squirl cage to create an exhaust back then? I left this thread days ago, I can see now, it will never stop blowing hot air, just like our exhaust fans.

doniboy said:

I doubt any of you have degrees, and even if you did, none of ya'll opinion are based in fact; ya'll are mostly speculating.... Both ways seem to work, and it's seem to be a personal preference. Ya'll are wasting your time trying to convert one another and or prove one another wrong when NONE of you really possess the expertise or have the scientifically tested data to prove that the other is wrong.... Which is why this will continue to be an endless and pointless battle that will span another 7 pages with the same conclusion... My way is right, and their way is wrong.

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I do have a college degree but you can go ahead and assume otherwise. What he(jrainman) was saying kind of goes against the basics of how air flows, but I don't care enough to explain it. Google is your friend.

Did you even read his posts? How about my other posts in this thread? I'm not saying either way is right or wrong. I said pulling burnt my bearings, I bought some more have been pushing ever since with no issues.

mr2shim said:

I do have a college degree but you can go ahead and assume otherwise. What he was saying kind of goes against the basics of how air flows, but I don't care enough to explain it. Google is your friend.

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Okay show me your research.. Even engineers with college degrees have to test out their scientifically base theories to see if it works. I work as a technician for a very popular manufacturing company. The company has very intelligent engineers who engineer most of our machinery that we use, and even there crap doesn't work half the time...

Unless you have tried and tested data based on using inline duct fans to push/pull air, then you really aren't in a position to prove any method wrong... I do not care what you have a degree in...

You are just one of those people that just have to be right that is arguing with other people who have to be right... That sums up this whole argument in a nutshell.

Edit: I see you added to your post. You're taking my first comments as personally directed at you. I'm saying in general that this is a personal preference that everyone has had different positive and negative experiences with. My point is that both sides are wasting their time.. This is like a PC vs Mac type of holy war.

when you push the air in to a sealed line, you create what is called static pressure, that is pressure pushing outward on your ducts,like blowing up a balloon.
pulling creates a negative pressure with no static pressure. In a/c, we pull the air across the coil.

what's easier? blowing up the balloon, or letting the air out? less resistance from letting the air out. so pushing is going to put more work on the fan. MY 2 cents.

doniboy said:

Okay show me your research.. Even engineers with college degrees have to test out their scientifically base theories to see if it works. I work as a technician for a very popular manufacturing company. The company has very intelligent engineers who engineer most of our machinery that we use, and even there crap doesn't work half the time...

Unless you have tried and tested data based on using inline duct fans to push/pull air, then you really aren't in a position to prove any method wrong... I do not care what you have a degree in...

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I could explain to you how the venturi effect works, just because I haven't ever tested it myself doesn't mean it's not proven. Like I said, Google is your friend. What are you talking about anyways? When did I say, "pulling is bad bad and you're a dummy if you do it" Have you READ anything I've posted in this thread?

doniboy said:

Edit: I see you added to your post. You're taking my first comments as personally directed at you. I'm saying in general that this is a personal preference that everyone has had different positive and negative experiences with. My point is that both sides are wasting their time.. This is like a PC vs Mac type of holy war.

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When you directly quote someone, they tend to think the comments are directed towards them..

chuck estevez said:

when you push the air in to a sealed line, you create what is called static pressure, that is pressure pushing outward on your ducts,like blowing up a balloon.
pulling creates a negative pressure with no static pressure.

what's easier? blowing up the balloon, or letting the air out? less resistance from letting the air out. so pushing is going to put more work on the fan. MY 2 cents.

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Aren't the inline fans designed to pull are from bathrooms, basements etc? Show your test data to back what you say up? I say that there has not been ANY testing done either way, so do what works for you..

For noise reduction, I plan on suspending my fan from bungees inside my tent. It will then pull air from my filter which will then push air though my lights.. I'm doing both and that's what works for me until others show actual test that says I'm doing it wrong...

prosperian said:

hotrod, they didn't have electricity when you first started growing. Didn't you use a hamster in a squirl cage to create an exhaust back then? I left this thread days ago, I can see now, it will never stop blowing hot air, just like our exhaust fans.

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We didn't have hamsters back then neither. Well we did but not metal to make hamster wheels with.

mr2shim said:

When you directly quote someone, they tend to think the comments are directed towards them..

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LOL it's because you can't prove anything, so just direct me to google huh? Link me to test data?

You need to reread my comments...Yes, I quoted your comment about if someone "had a degree", but the wording of my comments were very generalized, and the point was that most of the people arguing not having degrees on the subject. It clearly made no references to any of your other post or anything else you have said. I used general words and phrases like like "any of you", ya'll, and "one another" to describe how pointless this argument was.... I did not say either side was wrong.. Just that neither side has posted any proof to back their claims because they can not lol...

doniboy said:

For noise reduction, I plan on suspending my fan from bungees inside my tent. It will then pull air from my filter which will then push air though my lights.. I'm doing both and that's what works for me until others show actual test that says I'm doing it wrong...

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That's exactly how I now run my setup. "Pushing" I did "pull" Meaning the fan was AFTER the light. In my post, I believe #60, I described this.




Here's how I USED to run it years and years ago. It didn't last 2 months before the bearing grease was gone and they were squealing like a stuck pig.


In both setups air is being sucked into the filter. The first pic air is being "pushed" over the light, in the second air is being "pulled" over the light.

The poster making the claim "these fans" are industrial strength fans made for prolonged exposure to high temps without fear of bearing failure - I have a bridge I need to sell and quick. Got a minute?

I'm 63 and have heard so much frigging bullshit regarding claims of durability and reliability. Yes the fans were designed for those purposes. However, when Chin, Sun & Company made their bids they didn't price them with high temp sealed bearings. The priced them with cheap shit bearings. OK? Probably the cheapest Hung Low & Company could turn out. Chicken fat for bearing grease. Can you picture this at all? Do you believe in Santa if you don't believe about shit components making shit fans?

Don't get your shorts rolled up by me insulting your fan. And not all fans are cheap shit. But the ones I have seen in the hydro stores? Only 1 with a motor that turned easily and freely with little shaft play. The rest? Made in Taiwan and you can tell without looking.

Your money. If it can push or it cal pull and you have any doubts or don't want to play "Let's replace the fan fast" games the amounts of air you are talking about can be moved from either side of the hood.

mr2shim said:

That's exactly how I now run my setup. "Pushing" I did "pull" Meaning the fan was AFTER the light. In my post, I believe #60, I described this.

View attachment 2566706


Here's how I USED to run it years and years ago. It didn't last 2 months before the bearing grease was gone and they were squealing like a stuck pig.
View attachment 2566712

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Cool then... I've seen others with the same setup, and it seems to work well.

Yea man, I wasn't saying you are wrong. I was wondering the same thing... Which was better pushing or pulling, and have read countless post on different forums. I'm just saying, in my opinion, that no one has clearly proven the other one wrong. As heated as these argument get, if one side had hard proof that would shut the other side the hell up lol, they would have presented it by now. I haven't seen it though... Every time I watch a video on YouTube where the author shows his setup, these same arguments pop up in the comment section about how it's setup wrong lol.. I'm just saying do what works for you..