[firkin]

Not sure if you are wrong. I haven't tried the sucking as yet, although it was the way I would have ordinarily proceeded. After reading a bit on here and talking to some folk it seemed blowing was the way to achieve maximum cooling. Also in order to suck another carbon filter would be needed at the exit end. The glass seal is secured pretty tight with a foam inlay and may not draw any of the rooms odour into the ducts, but I wouldn't bet my front door on it.

[Magic]

mmmm interesting, i will still use these lights regardless as i like the way the holes are on the ends of the hood as opposed to the top, thus maximising height space. also i bet they are nice to link up together in a chain, with a fan and small length of ducting in between each one

[firkin]

Well this warm weather blowing warm air across the bulb isn't working out too well. The area of the shade that the the air hits is remaining coolish but the rest is hot as if no cooling was happening. I have reversed the shade so that the air hits the end of the bulb, and really no difference, so tomorrow am off to buy a small filter and sucking out it is. The plants although healthy are stunted due to heat stress.

[Jim_jim]

I heard that sucking is worse as the hot air is sucked thro the fan, which can damage it. Dont know if this is true or not tho!

[Magic]

Jim_jim, on May 3 2007, 02:24 PM, said:

I heard that sucking is worse as the hot air is sucked thro the fan, which can damage it. Dont know if this is true or not tho!

high,
no, this is not true as the fans rvk etc, are designed to suck or extract hot/stale/smelly whatever air, that is why they are called extractor fans, also they are designed to stay on or be able to cope with staying on 24/7 365.
and i maybe wrong but i always thought laws of physics states pulling is stronger than pushing, and sucking is stronger or more efficient than blowing.
just my 2penneths worth.
i have my fans both extracting, one extracts heat from hood, and other bigger one sucks through carbon filter
peace
merlin


edited for badspell

This post has been edited by Merlin: 03 May 2007 - 01:09 PM

[dead_eye]

Just a quick comment on this one, excluding equipment problems i.e over heating fans etc sucking air through over or under something is always the most efficient way of cooling something, it provides a constant high velocity airflow compared to the turblent flow blowing air causes (which in theory cools better but in reality doesnt due to the turbulance buggering the air flow up.
Ducting air in from outside makes a huge difference to cooling ability ( the easiest way is normally through a wall vent or through the ceiling to a vent in the loft under the facia boards) The only thing to watch there is that the air goes through some sort of a filter to ensure its not damp for obvious reasons.

we've toyed with a few different setups over the years just to see what can be done really, one of the best was pumping the nutrient soloution through a water jacket around the reflector then out through an old intercooler and back around again, might aswell put the soloution to use and the tubing needed to cool the lamp with water is soooo much smaller than with air!

another interesting way is a hiltsch tube cooler, easy to make if your handy on a mill and to be honest just uber cool to play with while your waiting for stuff to grow B) you need a compressor which is a bit of a bumer but the plus side is the tube can cool well into the minus figures so you can keep your grow room at exactly the temps you want using the two outputs and the light as heaters/chillers

Has anyone got any idea what the led panels are like on the heat they kick out?

[dead_eye]

http://en.wikipedia....iki/Vortex_tube
http://www.airtxinternational.com/catalog/...CFQ9KQgodX3-VmA not bad prices but a damn site cheaper to make your own theres a few plans kicking about on google

[bodderas]

Oldpink, on Jun 3 2002, 09:38 AM, said:

*EDIT*

see page 2 for more info

OP




this is how i solved mine, cheap and easy,

the first thing to do is mark a 3" circle on top of your lamp
and drill it full of hole's (the more the better) and mount a
4" computer fan over the hole's and screw it to the metal reflector
make sure it's sucking air out not blowing in

a glass shield is very usefull if you use this method

the pic's will explain the rest

hope this help's

Hi thre im on my first 250 w set up ! Have been having some pritty high temps 30+ OMG! I know.But thats when my grow tent /plastic greenhose is fully zipped up.I was going to buy an air cooled tube thingy for the summer months as ive now managed to get temps around 26.0c But im deffinately going to Maplins to get me an PC fan, are there both fans for blowing and sucking?, or do you just use the same fan, and use the other end.? For blowing and sucking .will let you know how i get on thanks.

[zealious]

Here is my newly built reflector.

would have never thought wood was safe but thanks to this thread I have put it to use.

this is a 400w mh construction light $25 usd that was taken apart and converted to remote ballast.

[zealious]

more pics





It works really freaking well. Im surprised. you can put your hands directly on the glass and its barely even warm.. absolutely no heat can be felt inches bellow the glass. i think I might be able to put this 5inches away from plants without even breaking a sweat.

the total cost for the used light and home made reflector came to 40 usd. not bad. thats about 25 British pounds.

If you want to see more chip DIY goodness... check out my grow. its going on right now. =D

[plantfreak]

guys i want to try and think of a good diy reflector... putting my building skills to use here... one problem... I want to use 120mm fans was just wondering though if anyone knew of a psu I can buy that will power loads of fans... From what I know the fans use 3 or 4 pin molex connectors however I might have 4 lights and need 2 fans per light and ill need approx 2-3m of wire for each fan... do you know of equipment that willpower this many molex fans from just one psu... I dont understand the technical side of electronics but like i said im good at make and wiring n stuff once told.... much appreciated

[fatfreddyscat]

Im no electritian but. . . . . (famous last words)

But I'd use an old tower PC PSU. Its low output but can handle a lot of fans as a fan uses a fraction of the power of the CPU.

Alternativly you could use a cheap variable plug in transformer from your local supermarket, you can vary the speed on these as well, probably good for 2 to 3 fans each.

Good luck.

[goldrusher]

No pics anymore these need to be re-uploaded

[nasar]

can you put a pc fan in those open reflectors to keep them cool? making a square fitting above the lamp in the shade and blowing air from the room on it? and then power it from same light fitting.

[CupboardCommando]

I know this is an old thread but i thought i would add my 2p anyway for fellow noobs looking for cheap ways to cool their lights.
all i did to cool my 600w hps is screw a 80mm case fan directly under the bulb to the socket/fitting and with the addition of another fan (200mm) blowing across the canopy i can have my light as close as 10" in a 4ft x 1ft cupboard and keep temps at a steady 75 degrees!
Hope this helps steer some people away from wasting money on cool tubes. The way i see it if your struggling to keep temps low your better off getting a lower wattage bulb than a cool tube, as you would most likely end up with roughly the same lumen output anyway. I know a new light kit is more expensive than a cool tube but it would save you money on electric in the long run.
hopefully you can all make sense of this as it sounded right in my head
happy growing
cc