Flexwatt placement question for DIY plastic rack

I am just trying to figure out the best way to heat the three tubs. I've never setup a rack, Flexwatt, or Herpstat before. The DIY how-to's show assembled racks with no attention to where the Flexwatt is placed.The top of my rack can fit 3 x 15qt Sterilite tubs at a slight angle so I was going to have all three of them on one shelf. Would it be best to just use one large 36" strip of my 4" Flexwatt aross the rear of the shelf to heat the 3 tubs? I have three 2010 hatchlings coming soon so I'm trying to get everything setup. I'll be wired to a Herpstat. I was going to put the probe in between two of the tubs to read the temp and adjust the temp as needed based on the readings of my Acurite thermo/hygro combos. I just want to make sure the tubs are at the proper temp/humidity before the snakes arrive next month.

Regards,

B

My rack sound similar. I ran one strip of 4 inch across the shelf in the back, and it has been working great. I put my probe on the underside of the tape and set it at 93 degrees. This give me a hot spot at 89-91 degrees depending on the tub I am checking.

made me work my brain here a little LOL.
I thought this was an interesting idea...........3:40 mark

http://www.youtube.com/watch?v=a2jgkjJ0cHY

That was a pretty interesting idea.... I may have to try it out...

only makes sense to me to set it up that way, then if everything is working right your temps should be dead on your settings, right?

That's the best video I have seen on Flexwatt. Thank you very much! I feel supremely confident in my setup now :) Can't wait for my trio!

Regards,

B

That was a good video, my only remaining questions is -

Can I run a strand of heat tape at around 3 feet long with no breaks, with a strand of heat tape at a foot long?

Will the Herpstat supply wattage per foot, or will, if I hook my probe to the three foot strand, will my one foot strand be cold, or consequently putting my probe on my one foot strand, will my three foot strand get too hot?

This is my setup
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| 3ft. |
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| 3ft. |
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| 1ft. |
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| 1ft. |
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| 1ft. |
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I would think that would cause a problem just because there would be different resistances?

You have to keep the flexwatt at equal lengths. I'm sure of that from all the reading I've done.

Regards,

B

Yup, I contacted Dion from Spyder Robotics, and he said he was sure using different lengths of Flexwatt would result in different temperature ratings from each run.

"They will not all be the same temp. There are differences in heat output
between different lengths of flexwatt and often even in the same lengths of
flexwatt even when they are at the same voltage. Its not an issue with the
thermostat but the difference in resistance and environment of the heat
tape. Even with a simple rack setup where every level has the same length
of flexwatt the top racks will be much warmer than the lower ones due to
heat naturally rising. However, in a standard rack its usually a couple of
degrees difference top to bottom which is not enough to cause a concern.

So typically when building a rack you want to keep the enclosure size the
same throughout the rack so that its easier to regulate."

Dion Brewington
Owner, Spyder Robotics