Downsides of using portable AC units?

WOW you have TWO 10" inline fans and you still CANT keep it cool?? that crasy what kinda lights do you have.....tell us the rest of your set up? where are you exhausting your hot air too? where are you pulling fresh air into from?? how big is your grow area?? so you using one fan souly for cooling light pulling outside air into lights then back outside the tent and your using the other fan for souly exhausting the tent? and have an olicilating fan for the plants?? and you still are in the 90's?

 

You must have some kind of other problem man, If you had even one 10" inline fan you should have no problems keeping that box cool as well as a 600w light. Are you exhausting the air out of the box, you said you had air pumping in and air being circulated but you didn't mention any sort of exhaust, all that air needs to go somewhere outside of your grow box.

EDIT: Yeah after looking at your journal theres another problem going on, even a 6inch fan should work to keep that space cool. I just think that a portable a/c unit is a bit on the extreme side for your grow space, those are mainly used for rooms or larger closets.

 

I've been using a similar unit to cool my growroom. It works great but mine is inside my growroom. Hookin up an outside thermastat is gonna be tough. Most thermastat systems just cut off the power when the room gets to the desired temp, then restores power when it gets to hot. Problem is when the power gets cut back on in those ac units, u still have to push a button for the unit to come on. So the thermastat will turn off your ac, but it won't turn it back on. If that ac is big enough to keep the whole room that your grow tent is in cool, then it can still be effective just using it's built in thermastat.

 

Hey Corp, is your 10" can fan sucking air thru your hood and out the box? Sounds like u have it the other way around in your first post?

 

CA, the most probable cause of the problem is due to you doing such a great job of creating an airtight box! By doing so you have also created negative air pressure inside the box; i.e. the fans are trying to exhaust more air than is available to them for them to work as designed. This is due to a lack of balance with the intake of fresh air coming into the box. the easiest solution is to create adequate fresh air input. Also, ensure you are pulling air and not pushing air. Those 600 watters put out a tremendous amount of heat and you are going to need to pull a lot of air across that light to keep the box cool and well ventilated, i.e. air circulation which is critical)

3" PVC elboxw (long sweep preferred) work great as intake vent pipes as the bend in the elbow will not allow light to penetrate inside the box in the event you have to turn on the lights during night time.

 

i just thaught i would mention that the only problem with the portable a\c is that youll have to empty the resevoir pretty often, maybe a couple times a day, a good solution to this is to make a hole in the bottom of the resevoir and attach a hose to it leading to a drain pipe or somthing along the lines

 

I think the problem may be that the closet space that the box is in just gets too hot and dosnt get enough circulation. I have measured the temps of the closet and it sits at about 82 degrees, but I believe that the 82 degree air blowing into the closet is rapidly heated by the light to the 90-95 im getting inside the box.



Sorry I didn't even see that post. Yep I think that's your deal. The space that u have your box in needs to be cooler to cool the box. I have a mother/clone box inside my grow room, it 3' wide by 2' deep and about 7' tall. I have a 400w MH at the top and a shelf on the bottom with 6- 3' floro tubes. The MH hood is air cooled with a 300cfm fan suckin air out the top, and a 12"X12" hole cut out in the door with a cheap vent cover over it to block some of the light from escaping. No inlet fan, just two fans inside the box to circulate air. Even with all the lights on my temp never goes above 78, but the ac in my growroom keeps the air gettin sucked into the box at around 70. So if u want your inside box temps to be around 80 then the air outside your box needs to be at least 70-75. The colder the air goin into the box is, the cooler it will stay in the box. Hope this helps u man. Good luck

 

I know you don't plan on using a window AC, but still, always great to know this.

 

Is the portable AC unit you're looking at have a duct that connects to a window? If so, you should know that it's not a sealed unit. The exhaust air from one of those could potentially be quite smelly since they suck air from the space and blow it outside. Just a thought...