Fan advice, its getting hot again

[Cyclone]

Just remember dingo,

from experience, if you turn off the fan cooling the hoods, and you don't turn off the lights,

the lights will stay hotter until they are switched off, and turned back on again with the fan running.

 

Eg. you should be able to touch the glass tube encasing the bulb when the fan is running. if you turn the fan off,

after you turn the fan back on, and run it for 30 minutes, you will probably still sizzle your hand

 

Cyclone -

[calaman]

God its a drama tryin to find a decent fan. I been looking at flow rates as the mixflo on the hoods is only pulling 130lps so i figured if i can get up to like 250-300 it should be heaps. So one of the shops just tells me that its not the flow rate you want but the wattage! Dont seem to make sense to me. For example theres 8" fan on ebay thats 230W but only does 670cfm (which is less than 1ltr per second) yet then 153W 200mm at urbangardener supposedly does 300+lps. Its REALLY REALLY got me fucked! Next newagehydro have a systemair 200mm 136w that does 390lps. Its 300$ but unless i get some contary advice i think i'll have to buy it as they reckon it'll do within 10% of that figure

Does anyone know of a 200mm fan that WILL DEFINATELY do 250+ lps?

[Cyclone]

A 8L V12 Ferrari gets to 100km/h in under 4 seconds.

A 8L V12 Diesel truck pulls 20 Tones with ease.

 

You might find a low wattage fan that exchanges air fast may not be able to pull that air through 5m of bent ducting,

or more so a carbon filter at even half the rate

 

Cyclone -

[calaman]

yeah but i cant fit the ferrari or the truck in my ceiling...

[Cyclone]

Then put it in the roof cavity between your grow room and your homes roof...

 

You cant fit it as in room, or you cant mount it?

[mull-ray]

Get a centrifugal fan. They hold static pressure and are designed for running through impedance such as ducting and carbon filters. I got a Can Fan a ways back and have never looked back. Centrifugals cost more than inline (radial) fans but are well worth it.

[Sytha]

Get a centrifugal fan. They hold static pressure and are designed for running through impedance such as ducting and carbon filters. I got a Can Fan a ways back and have never looked back. Centrifugals cost more than inline (radial) fans but are well worth it.

 

Right on the money!! Your inline fans dont build enough pressure pull the air all the way through that length of vent, these fans arent designed to push air. You need a centrifugal fan!!! I have two cooltubes hooked upto a 150mm centrifugal can-fan with a u-turn, 2 corner turns and it still blows a gale outta the end of the exhaust

[Pleb Scrubber]

Nice sytha, you even got the sound proof ducting... I wish I had done that instead of going the cheap option, then having to try to sound proof it ghetto style

 

Im about to get a second cool tube and set them up in sequence like you have done. I have a 250 centri pulling thru it, and it also exausts air out of the room.

 

I found with my cooling setup, you can suck more and more air thru it, but you get to a point where the temperatures wont drop anymore. After all the air your sucking in from outside is usually warm, and theres a limit to how much heat can transfer from the bulb to the air.

 

One problem I had when I hooked the cool tube up to the centri was that the metal halide bulb would rattle from the rapid airflow around it.

They are built with a thick wire inside them that loops around a piece of the glass bulb.

After a while I noticed tiny shards of glass building up inside the bulb where the vibrating wire had chipped away glass on the inside of the bulb.

I jammed a peice of wood in the tube against the bulb (fire hazard) and it fixed the problem.