need help setting up grow room

basically its a bedroom one window with blinds my plan is to create a space cheaply i dont plan on filtering smell i will by a box for frame of window cut hole for the ducting leave window open a tidge to exaust and bring in freah air couple fans in the space 15 plants in 11 l pots 1000 watt air cooled hps hung directly from ceilling also extractor and ducting hung from ceiling then put mylar up around the space 6" by 6" area attached to the ceilling to create room lights on during day off at night for light leaks i have grown before and was quite succesfull i dont worry about smell because of location my main worry is ventallation as i dont wish to make holes in walls