Air Cooled Hood

[boe~pimp]

i got a hood with my light & ballast that was an 'ablite' like an adjustable 'batwing' one but was rigid & one piece( picture here ) . My grow room wasn't cool enough in the first run, it wasn't critical, but i wanted to lower the temps. So i made this air cooled hood and am changing my idea from an active exaust system to a passive intake arrangement.

pic .......

Edited May 5, 2003 by boe~pimp

[boe~pimp]

side view..

 

the original reflector had a lip that pointed outwards so i bent it back around to support the sheet of glass. the ends i just made from aluminium & riveted them on... for an outlay of $0 i think the end product is quite nice hehe ::

Edited May 5, 2003 by boe~pimp

[Luke Skywalker]

Hi there boe~pimp! I've got the exact same "ablite" reflector! I had toyed with the idea of an air-cooled hood, but I've been advised by a few different people that the glass drops your lumens considerably, and that they're more hassle than they are worth.... Have you tried out this air-cooled hood and compared running temps? I wonder how much the temp would drop even if you didn't have the glass on the bottom, but with good fans running in the hood sucking out the air before it can get too hot, then you could have the best of both worlds? I just put my next cabinet on layby, a small pine double wardrobe, and I will have to be looking at getting my heat extraction together soon.... So, can you give us a comparison test? Maybe even without the glass but still running the extractor?

 

Talk to ya soon, and good innovation there boe~pimp, showing the great stoner ingenuity that we should all be proud of... I wonder how many of the great inventions of history were thought of whilst stoned....

[boe~pimp]

yer i haven't run it yet, if this doesn't work, i'm going to tri running both 6 inches exaust ducts from each side of the reflector without the glass so all the air in the room is going out through the reflector and vents (and heat to) the holes on the top would probably have to be covered up though. normal glass shouldn't block lumens significantly, if your counting them by single lumens you may notice the difference but when you have 55,000 in a 1.5' x 3' cabinet it should suffice.

sorry if it doesn't make much sense... as the signature says...

[pipeman]

I've got a combination meter from Bunnings that measures PH, moisture and light. It doesn't say what units the light measurement is in, but I'm guessing its LUX. Anyway, 300mm under my hood with a glass heat shield its measuring about 1800, but 300mm below my hood without the glass it measures about 2500. Both are a 400W Son-T. Fair bit of difference there. But of course you can get the hood with glass heat shield closer, and from about 200mm it gave a reading close to 2500. so you could say that although you lose some light intensity in the reflectivity of the glass it is compensated for by being able to get the light closer to the plants.

 

The other big thing with a glass covered hood is that you can have the bulk of your airflow through the hood and not through the cabinet, which makes CO2 injection easier. The trouble with small cabinets with a HID light is that usually you need to make your ventilation constant to keep temps down, which makes CO2 useless. However if you have a fresh air inlet and outlet to a glass covered hood, drawing from and exhausting to the outside of the cabinet respectively, you could get away with a small timed extraction fan to the main cupboard to co-ordinate with CO2. I'm not talking anything fancy, just a dripper into a tub with a few doses of CO2 enricha, which according to www.CO2enricha.com should provide a fairly constant boost in CO2 levels.

[boe~pimp]

in a closet grow i mainly want it for shorter distance between light & plants so thats what i'm after.

 

been running today:

heres the light in action.......

[boe~pimp]

and heres the other exaust....... (twins hehe).

The hood runs at a constant vacum which is what i was after... this combined with the other exaust fan keeps the whole cupboard running at a massive vacum as it is virtually airtight... my fans nearly stall when i close the doors so i'm leaving one open for now untill i install some flue vents.

Already i've observed a 10degree drop in temp, and for costing me no extra than my previous setup, just re-arranged, i'm pretty happy with that

 

we'll see how it goes when i grow some nl & vb next grow.

[Tom]

my fans nearly stall when i close the doors so i'm leaving one open for now untill i install some flue vents.

Yeah, plant's enjoy breathing as much as we do.

 

http://www.gamers-forums.com/smilies/contrib/ruinkai/coolgleamA.gif http://64.207.13.28/mysmilies/otn/glasses/smokin.gif

[boe~pimp]

they certainly do tom.

Also having my ventillation set out this way i can utilise my co2 method better than before. i'll be using a sugar, yeast & water mixture for c02 when i get setup again.

I can't see the glass doing much in the way of blocking light because all lights come with glass around them anyway. After sorting through some of the glass i had around here, and going through a few sheets finding out whats armaplex safety glass and whats not (very messy ) i ended up using a sheet of two layer glass with a laminate layer in the middle.

Temps are now at a consitant 23 degrees !

i'll let you know more when i do

Edited May 6, 2003 by boe~pimp

[pipeman]

mate all glass even clear will reflect light to a degree, and the amount which is reflected is inversely proportional to the angle of incidence between the light and the glass. Which basically means you will see the greatest drop in light intensity towards the edges of your grow area. This happens anyway, but the effect is magnified when using glass. In my one meter wide cabinet the light reading in the middle is 1800 and on the edges its about 900. Also dust & shit collects on the inside of the glass further detracting from light intensity. Have a play with a light meter with and without your glass, you will be surprised how much difference there is.