This is not a noob "where do i put the thermostat probe" question.. but more geared towards people who have AP racks specifically and know how the heat tape is installed in them.. and why there may be such a drastic temperature change from where the heat tape bends and the flat areas of heat tape the tubs rest on. Ali at AP wasn't sure so i figured i'd check here to see if anyone else had experienced this. So far i love my rack and plan on doing business with them again, just tryin to get these temperatures sittin right, and beginning to wonder if it may be a defect in the heat tape itself..

I had originally planned on placing my thermostat probe in the middle of the heat tape on the middle shelf, but after doing so, I soon noticed that this kept the tub from sliding in because of the snug fit (which is a good thing). I then decided to try the probe in the corner of the same shelf, directly on the heat tape, where it "snaked up." I then took an accurite thermometer and taped its probe to the inside of the middle tub directly above the heat tape so I could play around with the thermostat temperature settings and get an appropriate hot spot temp. Now normally, when i was just in tubs without a rack, I would have to set the thermostat 5-7 degrees higher than what i wanted my hot spot to be to make up for the heat loss when transferring through the plastic tub and the newspaper. I soon realized that when i had my thermostat probe in the corner where the heat tape bent, the accurite probe that was inside the tub was reading higher than my thermostat which was directly on the heat tape. I then decided to tape the accurite probe directly to the middle of the heat tape while my thermostat probe was left in the corner. My thermostat probe read 96.4 degrees while my accurite probe was 118 degrees.

Now my question is, is this suppose to happen, where the corner of the heat tape is so much cooler than the middle? And if so, will the long parts of the heat tape (on the bottom of the shelves) get hotter than the shorter strips running up the sides? kind of like more "surface area" before the bends? I plan on playing around with it more when I get off work tonight, but from my understanding, the heat tape is suppose to be the same temperature all throughout regardless of whether it bends or not. none of the heat tape was creased really, yet some of the bends are pretty tight, but thats just how it is installed in the AP racks. when i have the thermostat probe taped to the middle of the heat tape (without a tub in of course, because it won't fit) i get the expected results just fine with the thermostat set a few degrees higher than the desired hot spot temp.

Ali suggested it could be due to air flow or the sides of the rack being cooler than the middle, but i dont believe this to be the cause of a 20 plus degree temperature fluctuation, especially since my room is not cool at all.

any ideas? anyone else experienced this? when i get home i'll try taping the thermostat probe to the heat tape where it runs up the side, but the heat tape on the sides felt cooler to the touch than the tape on the shelves as well.