By the way, and to offer some personal experience to this topic, my reason for engaging in this discussion was the failure of my Dometic fridge. I had it parked on my driveway, which we use as a volleyball/badminton/basketball court, so it's pretty close to level except for a slight slope for water drainage. I went into my camper and noticed a pretty strong ammonia odor. I thought, "man, my blackwater tank is really fermenting! I didn't think I'd left anything in it!!!" So I opened the toilet flush valve and saw that it was empty, plus it didn't stink as much in the bathroom as it did in the rest of the camper. So, I figured something in the fridge must be causing it (at this point I didn't even know the refrigerant was ammonia...but I was about to find out). When I opened the fridge door I was hit in the face with a blast of anhydrous ammonia, and when I say "hit",. I mean HIT! It was one of the most powerful experiences of ammonia gas I think I ever want to experience. It HURT my face and eyes and caused me to immediately choke. I made it out of that camper like I was on fire. No lasting damage (I hope) but a good learning experience. Thus my interest in the ARP device. I also am in the market for a new cooling unit and am leaning toward RVCOOL which has information about, and recommends the ARP control.