Ok Appreciating the responses. Idling is certainly an option & possibly the best option under my circumstances. I was just checking if there were other options I didn't know about. I am trying to be considerate of Fuel Bonus, too.
I once saw a guy that had rigged up a piece of light duty flex hose (like clothing dryer vent hose) from the front vent door of the reefer to the driver side window. Each end of the hose had some sort of box (looked homemade) attached to it that fit the vent door and the window openings. I imagine something like this would work pretty good... Especially if you placed a small fan in the window box to draw air through the hose from the reefer.
How much is the fuel bonus??? It May pay better to forget the fuel bonus and keep your foot on the floor and get more miles, instead of puttering along going slow to conserve fuel? Then you can idle to your hearts content.
I’ve seen 3 so far. Gasoline generator, with a 500 btu a/c unit in passenger window. I had a 850 btu single hose portable, running off 2000 watt Generator. All bought at Walmart, It worked good at night, but not so good above certain point, 85 daytime- no good. Like Truckdriver31 said 2 hose portable units are better. Single hose units a waste of time.
It's like a sauna outside this morning in San Antonio. Not in my truck though... up to 9 mpg by turning the key off every time the truck stops and keeping my foot out of it. This runs off a 3500 watt gas generator—$5 a day.