Thanks for experimenting and the results were as you expected 🙂 I did my own experimenting today during an easy run that last 1 hour and the temperature was 20c where I was running under the AC and the AC was set to 21c. I put a 1.5 liter jug under the drain pipe and after an hour almost exactly 1 liter was in the jug. I assume it would be close to 2 liters if running hard. I have had great experiences with Panasonic and TLC ACs so not sure if "my AC is the best ramble" is accurate but whatever floats your boat.
Anyhow, I figured out this AC icing issues that I have had over the the last 20 years in Thailand in my exercise rooms. All the responses claiming it wasn't the humidity got me thinking. I knew it was the extreme humidity in my small exercise room that was causing the icing without any doubt.
Solution, run my AC as a normal person does. Set it too 21c for a couple hour before the run so the coils aren't as cold when I start my run. The AC can then rid the room of humidity and the coils won't ice over. Also run the fan for a few hour after exercising to dry the unit out which only draws 14 watts.