can't beat the heat

i have a heat problem, and would appreciate some help.
here are the specs:

grow room is 4fx4fx6.6f (1,2mx1,2mx2m). running a 400W Son Agro HPS. got a fan circulating air inside. extractor is 4,7inch ducting (120mm) with 190m3/h inline duct fan.
inlet is one hole with 5,1inch ducting (130mm) with 205m3/h inline fan.

the temp with light on is between 31.5 C and 38 C (88F and 101 F).

I don't have a cooltube (Don't get them in S.Africa, and too expensive to import). Air cooled hoods are also not available. a mobile air con is on the expensive side too.
is there anything that i can do otherwise to bring the temp to a constant 26C (78F) without expensive equipment? the humidity ranges between 31 and 40. i'm in vegistative growing stage, and would like to get the humidity up to around 50-60.

appreciated...

well, the only thing you can really do is increase the size of your extractor fan and use the old extractor with the other intake fan to boost the fresh air input aswell.

Can you get hold of a large, unglazed clay pot that has no hole in the bottom? If so, fill it with water, and direct a stream of air around it. as the water evaporates it will cool your area and up humidity. Africans have kept water cool like this for many generations.

the cool tube is the way to go IMHO so mabee u could make one https://www.rollitup.org/do-yourself/49801-homemade-cool-tube-cab.html?highlight=light+tube+diy+homemade
or
Homemade 1000w cool tube! - Cannabis.com Forums Message Boards - Medical Marijuana, Cannabis Club, Dispensary, News

I have a cool tube in my cab and I found that I needed 2 fans 1 intake and 1 exhaust
GL

thanks for all the recommendations. i will experiment and let you know what's potting, pardon the pun (lol)

You can also try to enclose the light yourself, using a pane of tempered glass on the bottom of the enclosure to pass light. Then hook up ducting to the light enclosure as if it were a hood (as it basically is at that point.)

You see this a lot in grow cabinets divided up by horizontal shelves. The uppermost shelf is replaced with a pane of tempered glass, the light goes above it and some weatherstripping goes on the front lip of the glass shelf and the back of the cabinet door where they contact each other, to form a front seal. The sides and back are sealed with silicone, caulk, window putty, gaffers tape, etc. Ducts go in and out of the cabinets' sides, above the glass pane where the light is mounted. No problem.

thanks maccabee, my grow light is under an adjust-a-wing reflector, suspended from the roof of the growing room. how can one attach a sheet of glass to the under side of the reflector?

Last night I put the 200m3/h extractor in the growroom with the 150m3/h extractor already in there. The inlet is one 130mm duct, with a 5m3/h inlet fan. temp is only down to around 31 C. I put the one extractor duct against my face, and the air isn't even hot??? still hot inside.

the growroom is a simple wooden structure, and the sides are white roof insulating plastic, with black roof insulating plastic outside. roof is hardboard (pressed wood)

a container with water inside the room does nothing. does extra CO2 raise the temp a lot?

The temp outside the growroom is around 28 to 30 C. The growroom is inside an outside room, extra “granny flat”.

Co2 wont raise the temp but will help the plants handle the higher temps better

I use old gatorade bottles filled with ice. I switch them every day and just alternate the new ones with old ones its free and easy.Will raise humidity aswell.

Motman said:

thanks maccabee, my grow light is under an adjust-a-wing reflector, suspended from the roof of the growing room. how can one attach a sheet of glass to the under side of the reflector?

Click to expand...

It's a little trickier in that situation, especially if you don't want to keep the light in a fixed position. When a light is mounted in the top of a cabinet, it's much more straight forward.

However, with the Adjust-a-wing, you may be in luck! Look at this:

Adjustawing Reflector: Basement Lighting Hydroponics and Plant Grow Lights

That's just somebody's random product page, but it shows that there's a heat shield made for it. You need to find someone to sell you that accessory. Then use high-teperature metal repair tape under gaffers tape to seal the ends of the reflector around 4" duct couplings. (Don't use the regular metal duct repair tape. You will need the high temp variety, it's going to be close to the bulb even with the airflow.) Cutting some sheet-metal blanks to take up some of the space between the couplings, the reflector and the heat shield so it's not all tape would be good if you have the tools. You don't need to fit the space precisely just to fill some of it in and it will be much stronger than relying on just metal tape and gaffer tape across the sides. Offset the attachment points on either side of the reflector so the air-stream has to flow diagonally across the reflector and around the bulb.

Anyway, then attach 4" flexible vinyl dryer duct--the tape won't hold up as well with a directly attached metal duct. Bring the vinyl ducts up to the rafters to mate with metal ducting (flex or fixed, your choice) run to intake/exhaust ports in the rooms walls or ceiling. Attach a blower fan to system. You will block a little light from the sides by taping them up, but it shouldn't be too bad.

That's what I would do. You'll still be able to raise/lower the light, just do it carefully.

I admit i have no knowledge of import taxes and what not but dude, try a Bake-A-Round off ebay there cheap as hell andits essentially a 3.75" diameter pyrex tube. Voila insta cool tube.

thanks for the info everybody! you made me a happy chappy!
this is one of the most helpful forums i've come accross so far!

thumbs up!!