2Biz,
Thanks for giving me a chance to clarify. The Gerand Metering Valve comment was unrelated to the Mr Heater ... so that is probably where the temporary confusion is. It is just that it appeared to me that you went through a process of tweaking flows of some of your ball valves. I assumed that by observing that some of your ball valves were more closed or more open judging ... by the levers on the ball valves. I just commented based on our need to balance flows accurately ... the Gerands with the ability to verify flows more precisely has been helpful. I am not saying for sure that it applies to your system but just wanted to share the good experience we have had with Gerand Ball Valves vs ordinary ball valves when it comes to balancing & verifying flows. I hope this at least makes sense as to where I was coming from in posting in the manner that I did.
As far as the exhaust considerations of at least most ventless heaters ... it might not be relevant to your situation. In our situation ... we have to be very careful not to have any exhaust seep in to other areas of the rest of the adjoining areas of our facility. I remember visiting with Kate Car when she was Editor from Professional Car Washing on the phone once about carbon monoxide ... but that was a quite a bit different ... it was in one of our isolated separated car wash bays & occurred because of a driver leaving his vehicle on while he was washing & was rendered unconscious (but was rescued by an alert person waiting in line at the car wash). A car wash owner without
doors on both the entrance & exit probably would have more difficulty relating. The guy needed to be emergency airlifted to a Minneapolis-St.Paul Medical Center ... so it was not trivial.
Mike Walsh King Koin North Dakota