I need to lower my temps five to ten degrees

[thal]

Equipment list:

GL145 tent 4'9" x 4'9" x 7'4".
600w HPS
400w CMH
Hydrofarm Growzilla reflector
Can 50 with 6" 440 CFM can fan
Dayton 463CFM fan for venting the reflector.
Ambient room temp 70 degrees.
Current operating temps 81-89 degrees.

So I've had this current setup running for the last 4 weeks to veg my plants. I was a little concerned because the flange for my vortex got delayed by 2 weeks, so I had it loosely connected to the reflector, but it wasn't an airtight seal, in fact, there was a 1/2" gap or so between the reflector exhaust and the fan intake. At this time my temps were between 81 and 84 degrees.

I get the flange, hook up my reflector, and wait for the temps to drop. They seemed to dip by about 1 degree - not exactly the change I'm looking for, but it is 90 degrees outside so I figure the high heat is something I'll have to deal with.

Three days ago I switch the plants to flowering. I decided to let them flower at night so that we don't have extra heat from the sun beaming in. The problem is that during the night our temps drop from 90 to high 50's, so the air conditioning turns off and the temps sky rocket. I guess we are having colder nights recently because the last few weeks my temps never got past 84 degrees, which is too hot for my taste but acceptable until the fall.

Last night I went in to take a look at the temps and they had reached 89 degrees, so I turned off the 400w CMH and just left the 600 going. That lowered temps to 80 degrees, which is still a little hot but livable. However, I really want the plants to have the 400w CMH going to, especially during this first two weeks of stretch.

My biggest problem is getting the hot air outside of the grow room, while still maintaining security. I could probably build a window insert that vents the hot air out the window, but I'm concerned that it will look odd to neighbors, and even worse, what if it blows out stinky air?

I could change the fan setup, and hook the carbon scrubber up to the reflector and have it push air through it and out the window. I have to follow plant restrictions so I have a limited number and the can 50 should have no issue scrubbing my small tent.

I can change it so that I'm blowing the hot air out into the rest of the finished basement, but that means I would have to shut the door when guests come over and that could heat up the grow room when I don't have a lot of options.

I don't have the extra funds to get a window or stand alone air conditioner or else I would do that. I also don't want to crank the AC in the house any further because it is a split level and they are already expensive to cool.

I could really use some advice.

 

[csharper]

Preface: I have a hunch you are overthinking this and you are actually at the temperature ideal. Air cooled 1000 watts in a properly ventilated tent in a room that stays 70f should be fine.

Where are you measuring temperature - at the canopy or floor of the tent? If the floor, then you are right to overthink this and you have a ventilation problem between room and tent. However, if you are measuring at the canopy, then step back a second and think (I have been in the mindstate you are in, but this is where you need to be and is all based on my obsessive semi-scientific observations):

1, is your thermometer an infrared thermometer or just the cheap digital or analog type?
2, If not infrared, is it black? If so, and even with white thermometers, there is heat buildup in the device itself, which makes the device read higher than an ir thermomemeter on the leaves (up to 10f)
3, Finally, floor vs canopy comes back into play. If you canopy is 90 and your floor by the intake vents is 70, that is pretty close to North American September when these plants flower. If you use AC to drop your canopy temperature 10 degrees, then your root zone and house is gonna be 60 which is probably worse for the plant.
4, Simplest thing is to forget the 12" light height stuff and remember your tent walls are reflectors, and move the lights up as high as possible, bringing the canopy/floor temperature closer.

I wrote all the following first, but then realized that we are both overthinking this and while the following is true, it is actually the wrong way to think if your whole house cooling can already maintain the room at 70. Because what I am saying about different zones is negated by that fact.

---- first pass at response:

in summary, you are asking for a way to remove heat energy without using any energy. What you have to do is spend $ on a used window unit (8000 btu is the MAX you would need, as much as half that if you consistently have).

Basically, your problem is you have equipment giving off heat, and no way to remove it.

cranking the whole house ac is not the answer - it is obvious that your grow room is in a different thermal zone than the thermostat. So bringing the AC down will have a non-linear change in the hallway with the thermostat vs the growing room = waste of energy = money you could invest in window unit

the only other option that is and will look stupid and probably won't work is to get a network of box fans (like 1 per 10 feet) or a proper blower and some ducting and pipe/ the hot air out of the grow room to the hallway or wherever the thermostat for that floor is.

 

[Dorje113]

Assuming your temps are too high, and 90 is getting there, but low-mid 80s should be ok....

I hear you about the funds, but find $100 and go to Home Depot and buy the 5000 Btu A/C, or, look on craigslist... but what it comes down to is you need it, and it is worth whatever it takes to keep your plants happy. Sometimes good or bad growers aren't determined by how much they know, but by how much they are willing to do to keep the plants happy. There can be no excuses and they must be your top priority if you expect good results. Saying you can't afford to spend $100 or crank the house a/c is indicates an adjustment of attitude or perspective is needed if you are planning on your crop succeeding.

I'm not trying to be a dick, I'm saying this because it kills me to see good people fuck everything up because they are too lazy or can't afford $100 to save a $5000 crop. I've seen it time and time again....

 

[thal]

I'm definitely not willing to sacrifice the whole setup over $100. I've been doing this for too long to do that. This is just a brand new setup and house and this has surprised me.

I think the first thing I'm going to do is leave the door open today and put a large fan in the room to help circulate the air out. it isn't ideal, but I think I only need to survive the summer, and if I had to close the door because of guests I could just run the 600 and that would stay at acceptable temps.

I have a cheap indoor/outdoor digital thermometer. It is laying on the bottom of the tent, in the shade, and the probe is toward the ceiling of the tent, right at the reflector level but not in the light. Those temps are pretty close, a few degree difference.

The odd thing is that none of my plants are heat stressed at all, and when I put my arm under the reflector it is comfortable, especially with the fan blowing on the canopy.

I appreciate the suggestions.

 

[toastfighter2]

A window a/c would be your best bet, but dumping some of the heat from your room might be a good idea to. With all the extra heat, a humidity problem is just around the corner. If you have the head room to do it, you could mount your can filter right above your light, draw through that, to your fan, and dump the clean air outside.

 

[thal]

My humidity won't be a problem. It stays at a pretty constant 37% thanks to the dry climate and basement combination.