Steven, passive AGSS is “frowned upon” in the UK now (as HTM 2022 will no doubt indicate). Active systems are now officially recommended.
Personally, however, I believe that any AGSS system is simply a waste of money, as long as the theatres are adequately ventilated. Most anaesthetic mixtures are heavier than air, so the low-level exhaust ducts (ie, about a foot above the floor) found in modern theatres are more than adequate in getting rid of exhaled gases.
By the way, in my experience, early (passive) AGSS systems were simply a spigot at the low-level extract, with the familiar convoluted tubing running from there to the expiration valve.
How are your theatres out there in Nova Scotia, I wonder?
