My Edgestar 28 runs a good bit but not all the time. The 28 bottle Thermo-electric units are at the maximum limit of Thermo cooling capacity and are going to run more than a smaller one to maintain temps in the summer months. 78 outside to 66 in the unit is a pretty big job for a 28 bottle Thermo. Mine does hold 65-66 very well though even when the house is a little warm when I come home in the afternoon.
RH in my unit holds 64-66 most of the time but does spike up or down every now and then. I have found that if I cover the front of the unit with a blanket and it holds much better temp and humidity. I am using 2.5 lbs of beads in 1/2 pound bags.
And of course, make sure you plugged the hole!
