Experienced Grower Having HEAT Problems - Please Help!

[SpoCannabis]

Thanks for stopping by, it's been a while since I've been able to spend any length of time on ICMag, but I'm hoping to be back for good!

Here's a lil background on my setup... its a recirc. DWC (based on my bro blaze's setup), total of 28 buckets - 12 in one room and 16 in another. Both rooms are connected via recirculating DWC to a central 30gal controller and 45gal rez. I use an EcoDrive 600gph pump to recirculate the system, and several GH dual-diaphram airpumps to provide the buckets with sufficient levels of dissolved oxygen.

I have two different flowering rooms framed within the basement of a house. The first room is 8'x10'7' and the second is 12'x10'x7'. Both rooms have an 8" Vortex Pulling air from the room through a 4' CanFilter (sitting on a crate) and out the room, and up the chimney. Not to mention two wall-mount 16" oscillating fans for circulation.

Each room has two 1000w HPS w/ 6" air-cooled hoods, with the ballasts mounted outside the rooms. The lighting system in both rooms are mounted on 6' Moving Light Rails. Each rooms has its own dedicated 6" Vortex PULLING hot air from the hoods and to the outside.

There is a propane burner in each room for Co2 enrichment, however neither have been turned on. After seeing high 80's and 90's, I felt adding A/C would be my next best option to control heat throughout the summer months....mind you, its only reached about 85 here; which means I can expect to see 10-15 degree increases throughout the coming months... == BIGGER problems.

So I purchased an 11,000 BTU portable A/C, initially just for the basement - to cool the intake air into the room. A buddy of mine had an interesting idea that we tried out - He took a large garbage can and put it upside down over the A/C unit to "dam" the cool air, then cut two 6" holes in the top (bottom), where he inserted the 6" ducting hose, piped into the two rooms. He also added a 6" booster fan to the end of each 6" ducting - at the point of entry to the rooms. The system seems to work pretty well as you can definitely feel the cold air entering the rooms, and you cannot feel the cool air escaping anywhere around the garbage can. We exhausted the hot air from the A/C out through the dryer vent to the outside.

Still...after all of this, I am seeing high 80, low 80 degree temps... ugh. I have looked over my formulas for cooling, and see that, based on my calculations, I am exchanging the air within the rooms 1.5-2x per minute which should be more than sufficient to cool the rooms - specially since they are in a basement!!

Please help me out here guys/gals.... Any ideas/suggestions?

 

[afgooey]

hey spo seams as if you have done alot right,i dont know how permanent that 11,000 btu ac unit is but id think about steping it up to a 25000 btu seams as if you have alot of space to cool, how are you getting your cool air from one room to another if your using ducting make sure it insulated u dont want the air heating up before it gets where its going, your c02 generaors shouldnt put off to much heat from the pilot,but i understand leaving them off till you figure it out should make it quik spocompton summers get scoarching

 

[SpoCannabis]

Thanks afgooey... Yeah the ducting is insulated. And yes, SpoCompton summers get scoarching lol... are you a PNW guy??

 

[Billy Burroughs]

ya thats an awful lot of space to cool id even sugest scrapping a window mount ac unit and use your central air system if you have one that is if not then window mount ac units it is i myself am using a window ac unit 12000 btu for my 4' x 6' x 7' room and cant get it to hit 75 lolive got a room of equal size that share a common wall im thinking about knocking out the wall this way increasing my space to 8' x 6' 7' im getting a second card mid july and i dont see me being able to run 6 plants in the small space i got esspecially the trees im growing atm

 

[SpoCannabis]

Old house...no central air. Not using a window-mount. Its a portable unit.

Still, even w/o A/C I should have enough ventilation to cool the room much better than it is. With the added cooling of the A/C, I should be just fine temp-wise...but im not...

 

[Elcap]

Couple easy things:

1. Run 9pm to 9am. That will be the coolest period (at least here it is and we have similar climate, though you're a good deal farther north...maybe use 9:30 or 10:00). A look at the daily temp logs will tell you (this is Spokane two days ago):

2. Are you pulling your air for cooling the lights from the basement, or outside? I would have it pulling from outside air, otherwise it's blowing your AC'ed air through the hoods then outside and out of the space. My vent scheme for your space would look like:

Lights: outside air->hoods->outside air
Room: basement->passive intake->room->filter->exhaust back to basement.

Spokecompton...could be worse, you could be in the Yakivegas and the Tri-shitties.

 

[forwhat420]

Ok I know this is my first post so you may think that I do not know what I am talking about..But it is to my understanding that you can run much higher temps with the Co2. Usually 85 to 90 degrees is good for this type of enriched environment.

 

[SpoCannabis]

Thanks Elcap, I know about running the night shift lol. Unfortunately, I am running 24hr right now, as this is the first run and haven't setup my veg room yet. You're right, Yakivegas, and Tri-Shitties are pretty bad lol..

Also, I am sucking the hot air from around the hoods (at the top of the room), they shouldn't be sucking in cold air from the a/c vent that is almost ground level....heat rises....


forwhat420 - yes this is true, however my co2 enrichment is a propaner burner, which already raises temps typically around 10 degrees when running... meaning I need to be around 75 degrees BEFORE turning it on. Thanks for the imput though, welcome to ICMag!

 

[Elcap]

Some thoughts on temps:

Optimal temperature is 27-30 C (80-86 F) if you have strong light with no CO2 enrichment. Less than 21 C (70 F) is too cold for good growth.
Low temperatures at night are OK down to about 60 degrees outdoors, then start to effect the growth in a big way. Mid 50’s will cause mild shock and 40’s will kill your plants with repeated exposure. Keep your plants warm, especially the roots. Elevate pots if you think the ground is sucking the heat out of the roots. This is an issue if you have a slab or other type of cold floor.
As temperature goes up, so does the ability of the air to hold water, thus reducing humidity, so a higher average temperature should reduce risk of fungus.
Contrary to many reports, high humidity is not good for plants except during germination and rooting. Lower humidity levels help the plant transpire CO2 and reduce risk of molds during flowering.
Studies indicate the potency of buds goes down as the temperature goes up, so it is important to see that the plants do not get too hot during flowering cycles.

D. Gold: CO2, Temperature and Humidity, 1991 Edited by E. Rosenthal.

 

[SpoCannabis]

Interesting....I've always thought opt. temp was around 74-78... food for thought

 

[Elcap]

If I read your vent plant right, this is pretty simple to solve, IMO.

You are pulling room air, and blowing it up the chimney? Like this?:
Basement->room->filter->chimney.

The heat rises thing aside, you're pulling so much air through there that you are effectively blowing your ac'ed air straight up the chimney with a very little time for it to do any cooling of the surrounding space.

Thnk about it...all that air leaving through the chimney MUST be replaced in the basement or you'd have a vacuum. So it's going to come flooding in through window cracks, doors, etc from outside the basement and THAT air that's coming in, is going to be warmer than the basement, and definitely warmer than the AC'ed air it's replacing. Instead, try recirc your room air within the basement, using the remainder of the basement as a sort of "lung room".

I think you can easily solve your problems by putting your room exhaust right back into the basement and venting the separate air cooling the lights out the chimney (that air should come from somewhere other than your cooled basement room, or you'll be doing the same thing...blowing your cool air out of the room before it can cool anything).

The heat rising aspect is not going to overcome a 2x/min air exchange rate. Id' be surprised if you could get the space more than a few degrees below the ambient temps since you're blowing all your hot AND cold air up the chimney and replacing it with ambient air at such a fast rate that you're essentially going to stay close to the ambient temp. That's my take, FWIW.

 

[afgooey]

Thanks afgooey... Yeah the ducting is insulated. And yes, SpoCompton summers get scoarching lol... are you a PNW guy??

yeah i live in pnw also,love it here not to mention the best cannabis in the nation grow right here in my,pnw flower room ,lol.good luck with that,issue.

 

[SpoCannabis]

Actually pulling air like this... but i see what you're saying

Room-Hood-Fan-Outside
&
Room-Filter-Fan-Chimney

I'm thinkin, should I have my charcoal filter just recirc'ing the air within the room, instead of piping my possibly cool air out through the chimney? I want to continue exhausting the air from the hoods outside because it is extremely hot, I know that for a fact...

 

[HydroFarmer]

Hey Spo,

Long time no hear from. Good to have you back brother....

I read this thread and I am leaning towards what eclap said about sucking the clean air right out thru your chimney exhaust. I think 11k BTU's is plenty to cool a flowering room the size you mentioned. Try exhausting back into your basement and see what the temps look like.

Peace
HF

 

[SpoCannabis]

Hey HF, thanks for the input. Long time indeed... i'll catch up with ya later...gotta figure this heat problem out...

Ima try to just exhaust the air from the carbon filter back into the room, so there isn't so much of a vaccuum, pullin in warm air.... we'll see what happens... With the setup I have, I am limited as to what I can do as far as "fresh" air...

 

[SpoCannabis]

Ok everyone... tried recirculating the air pulled through the carbon filter back into the room... still seeing high 80degree temps.... PLEASE HELP! I am at such a loss right now...feel like everything was done right, but still seeing extremely high temps. Extremely frustrating - specially after spending so much on this system.

Help me out here guys/gals...

 

[FLhydroponics]

Whats your humidity?

 

[Payaso]

You seriously need a decent air conditioner big enough to deal with the square footage you have. It will cool and lower the humidity...you have too much water in there to consider anything but at least 5,000 BTU's of cooling power. And the jury-rigged air dam ain't worth the powder to blow to hell IMHO...waste of time and electricity.

Don't forget that the entire mass of water you have in there to do DWC retains heat also... so a chiller and reduction of the water temperature will help also.

You obviously need more air flow, two circulating fans is nowhere near enough. Take the front cage of the fan off to reduce load on the oscillator and they last longer Four fans at least!

A dehumidifier would also be a big help to the air-conditioning system.

Best of luck with this one!

 

[Payaso]

You need more fresh air!

 

[Guest 18340]

The general consensus is that portable ac units suck at cooling. I have no doubt that a window unit will cool your room no problem.
I live in the dirty south so you can imagine the heat issues I have to deal with, trust me that unit you have is just wasting ALOT of electricity. They can be made to work, but theirs a better way.
You have windows for a window units? If not, theirs mini split units. They're very efficient and so quiet. Alittle pricey but they are worth every penny. Just my 2 pennies.
Evl...