Yes, Blunt, and the intent was to be so. Overloading your circuits can be very dangerous, and expensive. Carefully find out exactly what is going on, and especially watch for overheating on wires cords and pluge as you do so.
And yes, runing both on a 20A circuit is possible, especially if they do not start at the same time. Generally the ratings are overstated, so the actual draw can only be determined by accurate measurement. And, most 20A circuits will take a bit of overload for a while. I have had both ACs running on a 30A circuit, but even with 30A breakers and plugs, they will begin to show a lot of heat, especially at the plugs, due to higher resistance there. Now, I do know that it will work, but probably is not a good idea to depend on.
