Need suggestions on cooling my grow?

MetalSmelter

Well-Known Member
Adjusted my intake so that its on the top of the chamber near the other fan, both outputs, intake hole is left for fresh air exchange, you can put your hand over the hole, and feel air being pulled in. Temp is currently 92F but seems to be rising.
 

MonkeeMan

Well-Known Member
yeah im growing in rubbermaids and been wondering about pc fans

in a way i think its easier just to get an intake fan and use that.. you can get them at any building store for like 20 bucks... theya re super powerful and you only need 1 of them

hope you figure it out
 

MetalSmelter

Well-Known Member
Talked to a friend today and he let me have a 12v DC PS, i'll wire the 25cfm intake fan to 7.5v DC on the PS i have currently, then put the 12v DC on the 35cfm output fan, drawing more hot air out than the intake is pulling cool air in.

Hopefully this will work, and bring me to the mid 80's, that would make me happy.

AFter my last modification on all 4 lights being on, have left it for about 5hrs without checking it, and its at a consistant 94F, so hopefully doubling rpm's on both fans will drop it even more.

The little guy is showing the first little nodes that will be my 2nd pair of leaves.
 

nickfury510

Well-Known Member
is your intake bigger than your exaust....if its not that could be an issue....something to do with air displacement....someone alot smarter than me figured that out
 

FrostickZero

Well-Known Member
well I know from computers that you want a smaller intake port for fresh air then a bigger one for the intake because if its bigger then your exaust then the air inside is pretty much going to be sitting there and you want the exaust system to be at the top and the intake at the bottom so that the air will go from the bottom to top thus removing the warm/hot air
 

MonkeeMan

Well-Known Member
hmmm never heard of them

just have a small hole to push air through and a filter

want to use an inline fan but i hear they are loud
 

MetalSmelter

Well-Known Member
Well i'm updating tonight with some temp reports and picture of my box, i'll also add more about the details of the box.

Temp is currently 98F. Its risen but has been rightt there constantly for the last few hrs.



As you can see the intake is on the bottom, the output at the very top. The black orb on the right side of the box is one of the sockets for the light fixtures, it holds 2 23w lights, same as the other side. The 9V supply is on the top output fan, as i calculated it, running at around 1875rpm and 26.25cfm, the intake fan is running at 7.5v, ~1060rpms and 15cfm. I'd say my space is around 3.5-4cf total. which is what i don't understand, why is it getting so hot when the math comes out that it shouldn't be getting nearly that hot.

They recommend 3-5x the airflow per minute, so 4cf x 5=20cf whereas my output is at the top/warm air rises, and output capacity is at 25cf. My intake is around 15cfm at the very bottom just for air exchange....

As someone mentioned earlier that the plant will acclimate to the warmer enviroment, i sure hope so, because i'm auwards of 95 during the day with the lights on, and down to a low of 70-75 over the nights with lights off, 18/6.

Temp is still hovering around 99F..........Is this hot good, its very hot, but not very humid. ~22% which is low for the temp. So the air is warm but not thick and hot, which dosent impede airflow or respiration.

I find that low humidity causes stress on plants. I recommend 50-60% humidity until the final 2 weeks of flowering. At this point, the humidity should be lowered as much as possible to encourage the plant to seal and protect itself with additional resin. (I am able to get the humidity to go as low as 31%) I have been able to frost things up considerably this way.
My low Humidity is perfect for flowering, but very low for the vegging stage, how can i raise my humidity some for the chamber? Putting a glass of water in, and sealing it fairly well except for the intake/exhaust to raise the humidity?

Daytime conditions should be 70-80 degrees without co2, 80-90 degrees with co2 until the last two weeks when daytime temps should be kept between 70-80 and co2 can be reduced to adjust for the lower metabolism. Night temperatures should be kept above 60 degrees to prevent stress
MY 99 degree temp is on the very high en dof that, but not sure how much co2 i have in my chamber........either way i hope it acclimates well, as i can't lower my temp any more than now.

Nighttime/daytime fluctuations seems to be right in line with whats recommended though for 20-25 degree change for a slight stressing of the plant....

I hope my grow goes well.

Sorry for the ramblings, i'm high :D
 

MonkeeMan

Well-Known Member
where are you measuring the temp? beside the bulbs or beside the plants?

Also get rid of that intake fan it is only hurting you, you should have 2 output and passive intakes at the bottom.

I know this goes against what most people say but use 18/6 lighting if you already dont, then at least for a few hours the plants can get a rest from the heat if its that bad

finally freeze some water bottles, and throw one in the bottom of the case by the intake whenever you think about it, and switch out the one that was in there

thats really all i can think of doing before you have to get a new fan man
 

MetalSmelter

Well-Known Member
I had at one point changed the bottom fan and repositioned it uptop, both outputs, seemed to do ok for a few then the temp went back up more, i'll try it again though since i have more power to each fan, but the fans are only ~4" -6" from the lights which may be a bit far, though they should still move hot air away......

I have it on 18/6 timer right now as is. off 12pm on 6am and that cycle. Temperture is taken right at the plant, plant is centered in a 8" pot so 4" from plant on rim of pot, Lights are 3" or so from the plant, hasn't stretched at all. Will change the fans again to bout outputting and both at the top. 1 will be as is on the very top centered and one at a end both blowing out......I had been putting icecubes at the intake fan it was around 85 at lowest but i'd rather not fill icecubes every hr-2hrs..
 

MonkeeMan

Well-Known Member
yeah man really i have no idea, you seem to have tons of heat in that small space... im building a new grow spot and youve made me reconsider how to build it

i might just cut my loses and go with a big inline fan
 

MetalSmelter

Well-Known Member
I added 2 more passive input holes as per suggestions, so 1 input hole same size of fan outputs, this is at 1 end on the bottom, 2 on the other end about the same size as the output fans. Both output fans are position on the top blowing out. Temperture during working droped down to 80F with the lights off and the top off.........Its currently 97F and has been rising as well.

I dunno what to do really besides get larger fans but i'd think a total of 40cfm between 2 fans would do plenty as far as air movement in a total of 12 x 14 x 18" which as by eyeballing it out to 3.5-4cf is actually almost 2cf of total space.......WTF.

Should i switch the fans to blow into the enclosure from the top and mabey force all of the air out of the holes at the bottom? Would swapping white drawing paper out for mylar improve my heat problems and reflect some of the heat from mabey being absorbed by the plastic and instead reflecting it away and then up as air moves away....

I just dunno anymore....

Temp will be down tonight so tommorrow i can try and solve it again.....
 

smokesignal34698

Active Member
What about during flowering, is that temperture too high or will it actually stress the plant allowing greater yield?

I hope i get that far, i do have a few more seeds in a damp paper towl/open bag, between some warm electronics, if i get a decent outcome, and learn this go round, and can pull it off without any hassles, then i will look into better genetics than i currently have, which is what i'm really waiting on.

Thanks for the help.
you cant buy a pinto and expect a bmw
#1 rule genetics genetics genetics
If you are growing bagseed and will only buy seeds if you have a good crop might as well save your money
If im putting in 90+ days better be worht it and beesters are definatly not worth it as cheep as they are.not hateing just giving you my thoughts.
 
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