A gallon per day is probably a very high water output estimate.
You could rig up a "P" trap to drain the water into, and that trap full of water will prevent air or bugs from entering the trap. Have 3/4" PVC drain go down to the outside of the RV, then down about 2", then over to the right about 1" then up 1/5" to end. Water will stay in the 1" of pipe and prevent bugs from getting into the pipe.
That is what we do with home air conditioners. They tend to put out a lot of water until the air is dry, then very little after that.
Fred.