Stuck on ventilation

[buysser]

hi friends, I'm having a problem with ventilation and im stuck. I have 550 cubic feet grow room above an insulated and heated garage in an attc and that is very well insulated inside and out. should mention that the weather where I live can get very cold and can get very hot with high levels of humidity.
I have ran a 10 foot 6 inch duct with an inline fan from a room in my house directly into my grow room. we keep our humidity controlled and our temperature at 73 to 75 degrees year round.
the room is ventilated with a 340 CFM exhaust fan that I have in coming right at the center of the top of the room.
I know I'm going to have to cool the room down dehumidify and heat. I can get a separate heater and a separate dehumidifier but cool in the room down has proven to be a problem. I started looking at dual hose portable air conditioners and I'm told by several manufacturers that I cant run an intake line from outside because it gets too hot here.
I am very concerned about stealth and I looked into a DIY but I don't think that's the best answer for me...
how do i cool my room down the right way?
Thanks so much

 

[buysser]

Reply to me: I'm going to use LED's to help with heat.. Any thoughts or questions I missed? Thanks

 

[labexperiment]

Would a portable air conditioner not be a solution?

 

[buysser]

Exactly what I thought labexperiment and that was the original plan but before I pulled the trigger I called the manufacturer and they said that if I ran air from the outside, and because it gets so hot here, the A/C wouldn't keep up and it would burn the unit out. A window unit drips to much for the attic and is too noisy.
Had it all planned out and that one call (glad I did) stopped me in my tracks. There's an answer out there but I just need to find it.
tks for the reply

 

[labexperiment]

If you match the sq footage to the size of portable AC you buy there should not be an issue. I believe 10,000 BTU can do up to 600 sq feet. But I may be mistaken on that exact number, you should google it. As far as the dripping, nothing a pot catch tray would not solve.

 

[KingJohnC]

For your plants you will need to exchange the air in your grow area at least 5x per hour, more to dissipate heat.

 

[buysser]

For your plants you will need to exchange the air in your grow area at least 5x per hour, more to dissipate heat.

I've been experimenting with my lights the last few days trying to come up with a trend and so far with all my exhaust running in take with the de humidifier my lights increase the temperature by about 15 degrees and lowers the humidity by about 10%. right now it's 95 degrees outside with 60% humidity and I'm sitting in 86 degrees with 38% humidity with a 70 degree line from the house coming into the room. I've got an ideal 12000 BTU Portable is on its way