# choosing a floor fan to blow straight up at bare bulb



## stonestone (Oct 20, 2012)

i need to buy some floor fans to place under 1k watt hps bare bulbs..

the lamps are one a flip flop box on for one hour off for one hour to avoid hott spots.
adding floor fans should help with this a lot! 
my question is which fan to go with?

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=202795625&R=202795625#.UIMynW8rXzk
(largest, by a lot @ 3150cfm)

or stanley blower (not sure that blows str8 up)
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=202795625&R=202795625#.UIMynW8rXzk

or are thos both overkill
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?productId=202020283&storeId=10051&langId=-1&catalogId=10053&MERCH=REC-_-product-1-_-honeywell;fan;202182997-_-202020283-_-N#.UIMzb28rXzk

thoughts?


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## bowlfullofbliss (Oct 20, 2012)

why not just air cool your light and not turn it off and on? The act of turning them on and off is the hardest part on a lamp, you're going to burn them out much faster this way, and confuse the hell out of your plants. Does the sun ever turn on and off to avoid hot spots? lol.

I have 3 of them and no hot spots


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## stonestone (Oct 20, 2012)

i get more coverage flipping them. twice the number of lamps with a small electric bill.
the sun moves around in the sky and behind clouds.. as long as the room is lit for 12 hours/dark for 12 plants won't get confused.. 
it is hard on bulbs and ballasts true...


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## stonestone (Oct 20, 2012)

anyone know the ideal amount of cfm?


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## OGEvilgenius (Oct 21, 2012)

I have a cheapy 15 dollar honeywell like your 3rd choice. I also have one bulb without a fan at all (also looking for another, but wanted to test) - doesn't seem necessary if you're exchanging your room's air constantly. 

Go with the 3rd option.


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## smoke and coke (Oct 21, 2012)

your link for the stanley blower is wrong. i have a stanley blower i use for an exhaust. you dont need a huge fan to blow up at the bulb. go with the small 10" a long as it can be turned to blow straight up.

this is not my pic but i did try it and it qorked great. it does blow the heat away from the bulb and the plants, but it also warms the whole room where a cool tube would just take the heat staright out.


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## wawa007 (Oct 23, 2012)

stonestone said:


> anyone know the ideal amount of cfm?


hehee whats up bro i c by the homedepot site that ur store is in berlin heheheh im from new britain it's nice to c someone from around me  neways u ask about cfm wright , idk how big ur grow space is but this is how u count cubic feet , u taking width times length times height so lets sey the width is 6 feet ur length is 8 feet and the height of the room is 8 feet so 6x8x8=384 cf and now u wanna know how fast u wanna move the air , lets say 5 min do u divide ur cf by 5 ... 384:5=76.8 cfm and that's how big of the fan u want but in case of vertic i would calculate the cubic feet of my grow and move that much air a minute because u don't want no heat build up in ur vertic at all  , I start building my own vertic but my light's r cool tube so i,m going to vent the heat out straight from them so my room stay cool ... good luck to u man


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## Clown Baby (Oct 25, 2012)

stonestone said:


> the lamps are one a flip flop box on for one hour off for one hour to avoid hott spots.
> ?


This is going to ruin your bulbs.


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## iadburner (Jan 5, 2013)

wawa007 said:


> hehee whats up bro i c by the homedepot site that ur store is in berlin heheheh im from new britain it's nice to c someone from around me  neways u ask about cfm wright , idk how big ur grow space is but this is how u count cubic feet , u taking width times length times height so lets sey the width is 6 feet ur length is 8 feet and the height of the room is 8 feet so 6x8x8=384 cf and now u wanna know how fast u wanna move the air , lets say 5 min do u divide ur cf by 5 ... 384:5=76.8 cfm and that's how big of the fan u want but in case of vertic i would calculate the cubic feet of my grow and move that much air a minute because u don't want no heat build up in ur vertic at all  , I start building my own vertic but my light's r cool tube so i,m going to vent the heat out straight from them so my room stay cool ... good luck to u man


Umm... I think that's just your local store. The site shows my local store as well...


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## Nizza (Jan 6, 2013)

Calculating Fan Requirements


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## legallyflying (Jan 6, 2013)

I used a honeywell and it worked pretty good. I would NOT get that big stainless fan, that is going to dehydrate and beat the hell out of the leaves. Another member that kills it on a regular bassis uses simply wall mart box fans set up on some wooden blocks. Really liked that idea. Not sure if he is using standard box fans which are about 2 x 2 or the smaller "RV" box fans.


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