I need an exhaust fan for my small room. about 4x4x10, low ceiling. I need a fan that can push air through a small carbon filter. I was thinking about using a car radiator fan with 5 blades and build it into a square box. these move a good amount of air and are easy for me to control the speed to keep it quiet. but now that I've built my carbon filter and tested it, I wasn't sure until now how much power it would take to push the air. now I'm not sure if my fan idea will be able to get up enough air pressure to push past the filter. ideas?
ideas for custom exhaust fans
- Thread starter lorenzo08
- Start date
I just came across this on ebay. it took a little bit, but then it hit me. 1-3psi and a 3 inch inlet/outlet. should fit a dryer hose, and have enough power to pull air through a carbon filter. not sure yet how much power it uses or how loud it might be, but a fan speed controller from a computer might be strong enough to run it. if not, I'll build a controller for it.
eBay Motors: Electric Supercharger Turbo Acura Integra RSX Legend TL (item 120283719037 end time Jul-21-08 19:02:39 PDT)
eBay Motors: Electric Supercharger Turbo Acura Integra RSX Legend TL (item 120283719037 end time Jul-21-08 19:02:39 PDT)
buceye
Active Member
why not just use standard blower your going to pay $ 60 for some blower for a car . Come on get the right stuff go to htg get a squiral cage fan for 75 if you have ac air running through or 120 for the larger if air is ambient to outside temp High Tech Garden Supply
High Tech Garden Supply
High Tech Garden Supply
NewGrowth
Well-Known Member
Not all bathrooms fans are low cfm. I agree that link to the fans you posted are better and they are what I use. The reason I posted this is because he asked for alternatives
NICE. I like that idea better then any I've come up with thus far. how loud is it on low? I'll pick one up today.
I got one and put it together last night. great 
about $60 total for everything, and about an hour to put together. I didn't buy a flange. I used a 5 inch to 4 inch reducer and cut the 5 inch side to custom fit the inlet of the blower, then folded tabs over inside it. that part was easy enough to do. then, I used a curved oval elbo with a 6 inch opening at the other end and added a 6 to 4 inch reducer to that, and cut and shaped it to fit the outlet of the blower. I used a small drill bit to predrill screw holes to lower the chance of cracking the plastic. I used plenty of normal sheet metal screws to hold everything securely together, then some duct tape to make it air tight. I'm borrowing a camera, so I'll have pictures soon.
my final review, I think this project is of great value. I'm sure the power of the fan is near that of what the pro's use. it can almost be used as a shop vac, and you can feel a lot of air movement from 20 or 30 feet away even on low. it should have more then enough power to cool HID's and scrub with a carbon filter at the same time, in a small grow room. the shape of it's frame makes it easy to grab-and-go, or mount/hang within minutes. my only potential con is noise. it's no louder then any other fan on display at walmart, and I even watched stargate atlantis with it right below the tv on low. but, for a stealth room, like what my project is, it might just barely be noticeable from outside the the room, by the exhaust. my room's not ready yet, so it hasn't been tested, but I'm sure I can make it work. putting the carbon filter in-line, after the blower should kill 99% of the sound and work perfectly, just the way I like it.
thanks potlike, for the great link!
about $60 total for everything, and about an hour to put together. I didn't buy a flange. I used a 5 inch to 4 inch reducer and cut the 5 inch side to custom fit the inlet of the blower, then folded tabs over inside it. that part was easy enough to do. then, I used a curved oval elbo with a 6 inch opening at the other end and added a 6 to 4 inch reducer to that, and cut and shaped it to fit the outlet of the blower. I used a small drill bit to predrill screw holes to lower the chance of cracking the plastic. I used plenty of normal sheet metal screws to hold everything securely together, then some duct tape to make it air tight. I'm borrowing a camera, so I'll have pictures soon.
my final review, I think this project is of great value. I'm sure the power of the fan is near that of what the pro's use. it can almost be used as a shop vac, and you can feel a lot of air movement from 20 or 30 feet away even on low. it should have more then enough power to cool HID's and scrub with a carbon filter at the same time, in a small grow room. the shape of it's frame makes it easy to grab-and-go, or mount/hang within minutes. my only potential con is noise. it's no louder then any other fan on display at walmart, and I even watched stargate atlantis with it right below the tv on low. but, for a stealth room, like what my project is, it might just barely be noticeable from outside the the room, by the exhaust. my room's not ready yet, so it hasn't been tested, but I'm sure I can make it work. putting the carbon filter in-line, after the blower should kill 99% of the sound and work perfectly, just the way I like it.
thanks potlike, for the great link!
BigBudBalls
Well-Known Member
Thanks for the review lorenzo. I think I will go this route. Been looking for a fan for the 400w for the snow-grow. (winter)
glad someone found my babbling useful
still working on getting a camera
goblin7dg
Active Member
yep its all about the cfm's, the cfm are not correct on that fan though. the best similar blower is from Air king, i say best in regards to power/cost.
i been gathering some info, on this, its cool that someone allready tried my idea. guess it works. but lately i been surprice that you can get a cpu fan 120mm that pulls 100cfm for only 10.00 us dollars at Fry's electronics.
but heres some info i gathered on similar blowers:
Lasko Performance High Velocity Utility Fan 59.99 at homedepot online 42.99 @ lowes similar cfm approximately 190 setting 1- 260 setting 2 - 310 setting 3
Cool Shirt In-Line Blower Fan, 235 CFM, 4" Diameter- 42.99
Air King 9555 Portable Utility Blower -Portable Utility Blower 3 Speed Pivoting High Velocity Blower Wheel Dia 7 In CFM High 350 CFM Medium 300 CFM Low 250
Good fan compare website- Air King 9555 Portable Utility Blower
im gonna try the cpu fans just because the DBA is rated so much lower. thats what they use to measure how loud it is.
compare those to the "right stuff"
95 CFM ActiveAir Blower System for only what 80 bucks? ahahah
but yeah i remmember finding the airkings on a 2 for 80 buck speacial with no shipping cost somewhere online. if you find it let me know.
but before you buy that lasko, i would recommend you go to homedepot or lowes and plug it in. i know their has to be better. the dba is around 80 i belive.
hers the stanley blower cfm under 310 on highest setting web link
Stanley Blower Fan, Model# 655702 | Blowers | Northern Tool + Equipment
heres a nice cpu fan: with video but its costly at 50 bucks, for close to 300 cfm but the positive side to it is the under 50 dba sound. and the size is great for and inline duct setup. Stanley Blower Fan, Model# 655702 | Blowers | Northern Tool + Equipment
so many options, what i have found out is that anything from the hydro shops are overprice, they work duh, but similar stuff can be found for less.
i been gathering some info, on this, its cool that someone allready tried my idea. guess it works. but lately i been surprice that you can get a cpu fan 120mm that pulls 100cfm for only 10.00 us dollars at Fry's electronics.
but heres some info i gathered on similar blowers:
Lasko Performance High Velocity Utility Fan 59.99 at homedepot online 42.99 @ lowes similar cfm approximately 190 setting 1- 260 setting 2 - 310 setting 3
Cool Shirt In-Line Blower Fan, 235 CFM, 4" Diameter- 42.99
Air King 9555 Portable Utility Blower -Portable Utility Blower 3 Speed Pivoting High Velocity Blower Wheel Dia 7 In CFM High 350 CFM Medium 300 CFM Low 250
Good fan compare website- Air King 9555 Portable Utility Blower
im gonna try the cpu fans just because the DBA is rated so much lower. thats what they use to measure how loud it is.
compare those to the "right stuff"
95 CFM ActiveAir Blower System for only what 80 bucks? ahahah
but yeah i remmember finding the airkings on a 2 for 80 buck speacial with no shipping cost somewhere online. if you find it let me know.
but before you buy that lasko, i would recommend you go to homedepot or lowes and plug it in. i know their has to be better. the dba is around 80 i belive.
hers the stanley blower cfm under 310 on highest setting web link
Stanley Blower Fan, Model# 655702 | Blowers | Northern Tool + Equipment
heres a nice cpu fan: with video but its costly at 50 bucks, for close to 300 cfm but the positive side to it is the under 50 dba sound. and the size is great for and inline duct setup. Stanley Blower Fan, Model# 655702 | Blowers | Northern Tool + Equipment
so many options, what i have found out is that anything from the hydro shops are overprice, they work duh, but similar stuff can be found for less.
80db is pretty loud. if you get the 120mm computer fans, look for the ones that are thicker. the cheap thin ones are much louder and usually wear out pretty quick. I don't think a computer fan can push air through a carbon filter. the in-line fans at home depot, I'm also unsure of. they're more of a booster to be used with a large heating and cooling blower, so they probably wont be able to push much air through a carbon filter either.
I made a 12x4 square carbon filter. the blower I put together has way to much power for my little filter, even on low. so I'll be scrapping that filter and start over with maybe a 12x12 inch box filter and more carbon.
I made a 12x4 square carbon filter. the blower I put together has way to much power for my little filter, even on low. so I'll be scrapping that filter and start over with maybe a 12x12 inch box filter and more carbon.
BigBudBalls
Well-Known Member
I think the computer fans don't have enough 'oopmph' The ratings are in free air. Toss some ducts with a few bends, and a filter and it drops. The back pressure can also slow down the motor. An AC fan, I think, would have more torque to keep running at speed.
Just a thought, with nothing backing it. (at least not yet)
Just a thought, with nothing backing it. (at least not yet)
goblin7dg
Active Member
i see where your going though, makes sence. one is more well built/renforce for the road blocks involve in a duct syste, as to the other is not as strongly built to be run on dc power just to be made at a lower cost that conisist of cheaper, and lighter/weeker materials to have a comparable power rating with a ac unit.
or something like that, i suck at smart conversations, but i get stupider when i toke.
the air king still for the win. best blower for the price.
I have a funky set-up that works. I bought a 3 speed 9" desk fan at target for 12 bucks. One that is got the wire cage around it. then I cut the stand off. The fan nows fits inside a 5 gal. bucket. I put 8" holes in the bottom and in the lid. relocated the switch and thats it. A 8'' fan It works good. I have know idea how many cfm's, but it works better than the 8" duct fan (500 cfm) that I was using. Only thing its LOUD. Its sounds like the clothes dryer is running . But it works