I work in the HVAC field that deals with adding glycol to loop systems with fluid using several different means. I am not an expert on the injection by any means, we usually sub that out to a specialist. We would need to know how many gph and velocity the system returne vs the capacity of the hpop lpop and reservoir. Also an accurate diagram of the actual flow pattern. There is a possibility even on an open loop that thru the flow patterns internally that only a portion of that oil recirculates. I bring that up because I have seen systems that have glycol injection systems freeze for odd reasons like velocity differences or flow patterns not allowing the glycol to enter certain areas of the piping. I have also seen in hydronic heating system with piping where you actually get simulatanious oposite flows thru the exact same pipe due to temperature or viscosity differences. I had a 2" pipe that had heavier glycol water flowing say left to right in the botton of the pipe while at the same time thinner water with less glycol flowed right to left. I would never have believed it if I had not witnessed it myself. And it defied all reason or logic but we proved it by taking samples and temperature reading from the pipe. We just changed a couple of fitting to change the flow and the problem never returned.
I have also seen many strange flow pattern in air and water. I had a supply run cut too close to an elbow in a supply duct. This is a supply duct that blows air to the home from the furnace. The run/pipe was cut right next to a 90 degree elbow on the main duct. The air making that turn created a negative pressure area in a positively pressure duct which caused that new run/ pipe to actually suck air in. I had to moved the run/ pipe about 1 foot away from the elbow on the same duct and it blew like hell. 12" went from suck to blow in a duct that is a positively pressurized supply duct..
I changed my oil 400 miles ago, so I will pull a specific volume of a sample from my pan and put it in a clear glass and spot test on white paper. Then I will pull the same volume from from the reservoir he describes. If there is full circulation the oil should be very close to the same color/transparency. All though not pefect labratory analisys I would say if there is a difference in color/transparency, there is at least to some degree truth in what he claims.
If there are areas where the velocity or flow changes there may be "dead" areas thru that oil injection that would trap oil as he describes. I have rounded everything up today to give it a try tonight as soon as I have time and will post pics
Last edited by utah300rum : 06-25-2008 at 01:50 PM.