hi, i think i have some advise for you.. i have built 2 sealed rooms and i have helped my friends with theirs. a sealed room is the best but not as easy to deal with as 1 may think. heat is the biggest problem and most of it comes from the lights. so cooling the lights is the most important thing to do. remember, the closer the light to the plant the better it grows. you loose more than have the lumes every 6in or so. with that in mind you need the coolest supply of air to cool the lights you can find. you said you where going to use air from another room. if you run that air through the lights and back into that room you will heat that room. if you heat the room even a few degrees you will see the same increase at you lights. which means you might have to raise your lights a few inches. if you send the air from the room through the lights then outside, you would be venting out your house by creating negative air pressure in that room. which means your central air or heat will run more running up your electric bill. the solution is to pull air in from outside and return it to outside. i run my hose in my attic. i put them right at the suffet vents at opposite ends of the house. that air never touches the air in room so there is no sent to worry about. you want as much cfm as you can muster. that means long sweeping bend in tubes as much as it means big fans. straight as possible. now cooling the air in the grow room. this should not be hard if you are cooling the lights enough, mine are 85f degrees 1ft from 1khps. your portable ac will work fine if its a duels hose. if not you need to get a role of duct tape and convert it to one. this is real important because a single hose unit is not efficient enough and it vent your room out causing it cool new hot air instead of recooling the air it just cooled like a duel hose does. an ac guy probably explain the next part better but i try. your ac has 2 air inputs and 2 air outputs. the output that is cooled goes into room you want cooled. the output that is hot goes outside. its hot because it just cooled the condenser in your ac. thats the heat that was in your growroom. the feon carries it to the condenser. it needs to leave it there so it can go get more. if it can't get more your ac wont work. my point, is the same as the one for the lights. use the coolest air available to cool the ac dont run the lights and ac together. that would be biggest waste of electric. if done right you wont need a filter. the only time smell gets out is when you open door. if your running co2 this way is the best hands down. if your ac is single hose it will remove your co2 by venting out the room like i said earlier. you would be wasting your time with co2. i learned all this because i tried and tried till i got it all to work. wasted alot of time and money. i hope i save you some headaches.