1999 odyssey blows some cold air when moving

From your posting I am unclear exactly what the problem is but it seems your ac works when moving but not when idling. Could you clarify if the fan is working. Your belt could be loose as there is a greater load on the compressor when idling. Low freon could also be cause.

It could be a number of things. Check to see if the clutch is turning on the compressor. If it keeps turning on and off (cycling) it is low on freon. Is the condenser clean and free of bugs and road debris? Is the radiator fan coming on? If not that could explain why it is cold while driving, but hot while idling. Most all vehicles will blow colder on the AC when driving down the road because you are getting cooler air through the condenser. Hooking up a set of gauges to the vehicle will tell you best what is going on. Basic rule of thumb is: low side should be in the 30-40 lb range while running and the high side should be around 100 lbs higher than the ambient air temperature. Anything drastically different means you have a problem.