Printable View
Well, if you're handy in the workshop, should be OK. Zandor's looks fairly mechanically stable.
I'm only planning one alteration to Z's work- will be using silicone sealant instead of self-adhesive foam on the tube ends where they meet the sheetmetal. I think the foam would degrade from heat & UV and might indeed become loose. Silicone is an instant rubber gasket which will handle 500F all day for years.
I don't have enuf experience with exhaust fans to recommend one. Sorry.
I found 6" od bake-a-rounds on Ebay.
Dude - cooltubes ain't rocket science. You think they are, I know I did, until you install them and then you think, "I could have made this myself." There's a couple of good cooltube DIY's - Al posted one link above. If you're trying to save a few bucks, make it yourself.
That's a fairly long run, particularly if you're using flexible duct.Quote:
Originally Posted by criom
Axial blowers can't push into a lot of static pressure (backpressure). Air pressure leaks backward between the fan blades. Axials won't meet their CFM ratings if there's a lot of flow resistance/backpressure downline. Example of an axial fan.
Centrifugal types are better when you have to push air down a long run, through a few 90 bends or through a carbon filter. Example of a centrifugal blower.
I'm probably not giving you any good news as centrifs tend to be more expensive than axials. Sorry!
If you can shorten your duct run or replace long straight sections with plain steel duct, it'll move more air.
On the BGH cooltube the socket is connected to an L bracket which is attached to the sheet metal. The L bracket is attached with an eye screw & nut which is also used for hanging that end of the cooltube. So, essentially, the bulb is directly supported by the hanger. It would take a major calamity for that part to come disconnected and fall. It's, like, almost impossible.Quote:
Originally Posted by Al B. Fuct
The above mentioned mounting hole isn't air-tight. Since I'm sucking air thru the tubes, I don't care if it's air-tight. This whole cooltube concept doesn't require air-tight. It only requires that sufficient air be sucked past the bulbs to transfer the heat.
If the duct run isn't too long, I think this one will do it (edit: for 4" tubes). Rated 40CFM. We're only cooling one light, not venting an entire grow op. Presuming you already have a main exhaust fan.
For 6" something like this will do, but we're back to $57 and 250CFM (also presuming short duct)
If you bring in air from just outside the op and dump it just outside as well, it won't need any scent treatment. You'll only need to use care not to allow warmed air to get sucked right back into the op.
Airtightness depends on how you organise your airflow and scent control.Quote:
Originally Posted by PharmaCan
If you push 'clean' air from outside the op thru the cooltubes, they're at positive pressure compared to the op. Any cooltube air leaks will just vent 'clean' air into the op airmass, which will then leave the op through the main exhaust blower. No wucking furries.
If you suck air through your cooltubes, they will be at negative pressure compared to the 'stinky' air in the op. 'Stinky' air can then enter the cooltube via leaks and will exit via the cooltube fan. That air then has to be scent treated via filter, ioniser, etc.
I'd prefer to have fans upstream from the tubes for 2 reasons- the fan doesn't get exposed to the warm airstream from the lamp and the tubes run at positive pressure.
wow Al B. Fuct thanks for the examples and the link
that 6-In 250CFM is a great deal, but yea needs wiring and stuff...ill still try to get the shortest ducting possible (maybe i can get it down to less then 10 feet total)
also for me air leaks in the cool tubes does make a huge difference because co2 is involved. so i believe i would run them at positive preassure/upstream to be more effective?
great info :)
Al - you make a good point about the air pressure. I'm using the cooltube to exhaust the cabinet w/ fresh, air-conditioned air coming from inside my house. Since this is a veg cab, I wasn't worried too much about the smell. However, I am using a big exhaust filter.
Criom - Why do you need such a long run on the duct?
coolio. :)Quote:
Originally Posted by criom
no worries :)Quote:
also for me air leaks in the cool tubes does make a huge difference because co2 is involved. so i believe i would run them at positive preassure/upstream to be more effective?
great info :)
I think a bead of silicone sealant would make a leak-free connection.
If there's lots of airflow, such as in PharmaCan's case (he's got a bigmuthahompin' centrif on his cooltube), each cubic foot of air passing over the lamp tubes has to absorb less heat and has less time to do so than with smaller fans, so the actual tube output air temp won't be very high for him. He can get away with having his blower downstream, sucking air through the tubes. Betting his cooltube air exhaust temp isn't over 90F, probably less.
If you're not moving air at huge rates, it will get warmer as it spends longer in the cooltube. Fans of lower capacity should be placed upstream, blowing air first over the socket.
"Criom - Why do you need such a long run on the duct?"
because i was planning on mounting the intake duct to my air conditioner which is about 9 feet away, i could just intake from the room and use 3-4 feet.
"I think a bead of silicone sealant would make a leak-free connection."
should i be using this for every connection made even to the fan?
"If there's lots of airflow, such as in PharmaCan's case (he's got a bigmuthahompin' centrif on his cooltube), each cubic foot of air passing over the lamp tubes has to absorb less heat and has less time to do so than with smaller fans, so the actual tube output air temp won't be very high for him. He can get away with having his blower downstream, sucking air through the tubes. Betting his cooltube air exhaust temp isn't over 90F, probably less.
If you're not moving air at huge rates, it will get warmer as it spends longer in the cooltube. Fans of lower capacity should be placed upstream, blowing air first over the socket."
hm if i am going to get the smaller fan, and as you say it should be mounted blowing over the socket...would it be a bad idea to mount the fan right on the cooltube ? or maybe with a small piece of ducting in between it so it was blowing as hard as possible directly up the socket and over the bulb.
im not sure if the vibrations from that would damage the bulb or not, could block the light a little too i guess