Ac question

Hey,
I have always used other methods of cooling my grow room by air handling, but than I ventured to AC units to help with the finishing touch for my room that would run during day time. (other room runs at night) It seems that everyone runs AC units for there grows, but people forgot to mention that the AC unit that ducts out blows hot stinky weed smell out and stinks up my acreage. Thats unacceptable.
I have researched swamp coolers, mini ac splits and my favorite, the re-vamped monster grow excel stealth series. So now I am down grading, going to be running 6 1000HPS instead of 10, and running the system in a seal grow room with CO2. Any advice and life experience would be greatly appreciated. This grow will be underground in 2 twin 8x20 shipping containers 8 guage thick, only 1 foot of topsoil ontop of containers. Not looking for lecture for underground growing, just cooling a sealed room. Any help is appreciated! Thanks! Also This will be first run with CO2, any advice and products there would be great. I want to go burner with propane.
Oh, any info on diesel genset would be good. I know a few grows with them but they run at a bigger scale 40kw etc etc-not my interest.
I have done plenty of reserach on gensets etc and cooling a seal grow room but looking for advice from people, and problems they may have ran into.

I use mini splits

How well do they work?? When the lines say they are pre charged does that that mean they are a flexible tube and all you need to do is just quick connect the copper fittings?? Did you have any issues with the system well installing or getting it to run at full capacity? How loud is the condenser for the unit you purchased? My idea it has to be stealth big time because of increased family visits and the woman letting the grow continue.... I was thinking I would build a nice small shed and place the unit inside the shed and run the condenser underground with the air handler... Can you run the large outdoor unit inside a shed? And what about freezing issues, did u have to get a heat pump? Thanks. I do look for answers but most are vague and do not say wat issues u get if your winters can hit -48 but averaging -22C in BC. Thanks.

Any other advice? Anyone!.!.