Temp difference in rack.

[Beto510]

Hi all, so I've got a minor problem. I have a 6 tub rack that I built with 4" flexwatt hooked to my herpstat 2. The herpstat reads steadily at 99.9-100 degrees. Now my concern is the temps in the tubs I've only got the top two tubs with snakes in them. The lower on reads 91 degrease while the one on top is 4 degrees higher. Is this normal for a rack system ass the heat rises? Or do I have a problem the way mine is set up? Also how and where do you guys place your probes? I've got mine directly on the flexwatt held down with aluminum tape. Thanks all for reading!

[satomi325]

The heat difference between the top and bottom shelves are normal. The tops are always going to be hotter.
So adjust your rack temp accordingly so that all shelves are within an appropriate range. (Always under 95)
Maybe 88 for the bottom so the top can be a nice 92 (since you mentioned a 4 degree difference)

Also, you don't want to use aluminum tape to tape down the probe. It will trap heat and give you inaccurate readings. Tape the cord closest to the probe down(to avoid trapping heat on the probe). And you want it in the middle shelf in the middle of your flexwatt of your rack. I just use scotch tape to tape my probes down.

[RetiredJedi]

Yea, I tape just the very tip of the probe and then the wire closest to the probe.

[Beto510]

Won't scotch tape become loose after a while?

[snakesRkewl]

I have used HD packaging tape for a few years with no issues, I wouldn't use metal tape to tape down a thermostat probe.

I hope those are hot spot temps and not ambient temps?

[Andrew21]

If you meant 4 degrees between only 2 levels, then I don't think that's normal.

[RetiredJedi]

Won't scotch tape become loose after a while?

Where I tape mine in the places I said earlier I use skinny strips of aluminum tape.

[kitedemon]

It sounds like the room temp might be quite cool? What is the ambient room temp? Typically racks are kept at 80ºF room temps to maintain correct cool and ambient temps this also reduces the amount of gain there is.

[Beto510]

Ambient temps are at 80 degrees in my room and yes those are the hot spot temps I have a temp probe hot glued to the bottom of my tub. But now they are only two degrees apart maybe it's just normal. And yes i am only dig two tubs at the moment.

[don15681]

yes, there will be a difference in temp. if you have a temp gun. check the temps of the heat tape at each level. if you are using back heat, maybe put more air holes in the front of the top tubs. if using belly heat, I use newspaper and will put extra layers in the top racks.

might try having the 2 wires connecting to the heat tape at the bottom.