I dont know your code in your state but in Oregon or at least Portland you need to run a flue in the type venting for the appliance. Single wall, double wall, tripple wall or whatever it calls for, also if it does not have a spot to bring in fresh air to the unit you need to figure out how many square inches of fresh air you need and cut one hole 12 inches of the floor and one 12 inches of the cieling to bring in the combinde square inches you need. Just for example you would need 2 14/14 holes for fresh air.
If you need any help pm me, but like others have said be very safe and check your codes in your county. It is just not worth it and you could void any insurance you may have on the place. I hope all works out well.