Testing sampling location for independent ventilation system

400 sample sets would not be practical nor necessary, in my opinion. Even if you got the sampling done super inexpensive at $500 per sample set (if the sampling requirements are the same as U.S. LEED 2009 and you get a volume discount) that would be $200,000 and would take at least a month if all went well and nothing failed the first test series (very unlikely). How are these suites arranged (e.g., a lot of seperate low rise buildings with 4 to 10 suites per building, a single high rise building, several high rise buildings)? What is the square meterage of the footprint of the building(s)? How are the common areas ventilated if there are common areas? How much square meterage is in a suite (or what range)? Depending on the size of the footprint and how many floors I would probably just determine the number of sample sets on that information. For example, a 10 story building with a 4,000 square meter footprint would have two sample sets randomly arranged on each floor for a total of 20 samples ($12K to $20K cost done in a week or less if nothing failed - again unlikely). Of course, before you pursue such a course of action I would try to get approval beforehand. I can't imagine a reasonable reviewer would expect a sample set in each suite.