Pc Grow box. FIRST TIME how to mask the odor?

Ok dont laugh, im a newbie but im going to build a grow box, and insulate it with Mylar Reflective film and put 1 120mm fan and 80mm double ball bearing fan (1 exhaust 1 intake) and Four lights are 2400k (fall) and the other four are 6500k (summer) In order to produce optimal growth rates the 6500k light bulbs will be used during the seedling and vegetative plant stages. And than when flowering is ready plug in the 2400k bulbs for budding. Im going to use a lot of ona gel to help mask the smell but i need this to not smell like anything besides a normal computer. I have a med card but still live with my parents im (1 and they cant know about this. Ive heard about carbon filters but not sure where to get one, how to set it up and not trying to spend 150$ anything under 100$ would be good. Any design tips or ideas would be helpful, thank you!

Home made carbon filter and/or vent outside. That small of a grow should defuse very quickly outdoors. The unit needs to be air tight but still be provided air in and out. Negative pressure, you want a little more air going out than coming in. That way of there are any air leaks, it will suck in outside smell fee air instead of leak out stinky air.

sorry for the newb questions but how would i make a home made carbon filter? and im not sure if i can make a vent outside considering its a computer and hoses going out side from the back of a computer would be obvious, and would i have to keep the fans on all the time?