Please check with your local code enforcement as I am not familiar with Canadian codes. Although I wouldn't really expect them to differ too much from U.S. codes in regards to HVAC installations. Due to backdraft through ventilated soffits, doors & windows, the only feasible option is to run the exhasut & combusiton air intakes through the roof. Again, check with local codes to determine height of piping above roof line and distance of separation between exhaust and intake. Condensate is passive gravity fed so anywhere you can run the lines to outdoors or a drain should be acceptable. Use PVC for this as poly tube doesn't lay flat enough to accomodate total drainage.