11" flexwatt ?

How hot does 11" 20 watt flexwatt normally run?

I built a rack like Pwilliams58, and decided to use 11" flexwatt, because that is what Reptile Basics sold. I built the rack out of 3/4" melamine, and used 28 quart Sterilite tubs. I altered the rack by installing a 3/4" melamine back that I taped the flexwatt to. My flexwatt is running at approximately 110 F, but my hot spot in the tubs are only reaching 87 F. The flexwatt is running at 100% power.

I would double check your connections, is it soldered or crimped?

I believe there is no difference how HOT flexwatt gets regardless of whether it's 11" or 3". The 11" just covers a larger AREA.

I use 11" flexwatt to heat a row of 20 gallon long tanks placed next to each other, and 3" on my racks. It works great.

Ed I just noticed that you are using the 11" flexwatt as BACK heat. That's probably why you are having a hard time keeping your hot spot at 87 with full power. My guess is that while you are running at 100% your ambients are probably going to run high while your hot spots will run low.

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Originally Posted by llovelace

I would double check your connections, is it soldered or crimped?

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I used the flexwatt crimping tool to crimp the connections.

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Originally Posted by Jenn

Ed I just noticed that you are using the 11" flexwatt as BACK heat. That's probably why you are having a hard time keeping your hot spot at 87 with full power. My guess is that while you are running at 100% your ambients are probably going to run high while your hot spots will run low.

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My ambient in the room now is 77 F, so the flexwatt is bringing the hot spot temp up 10 F, but I thought that it would bring it up higher than that. I thought of running belly heat, but it would have been much more difficult to run than back heat.

BTW, thanks you both for your comments.

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Originally Posted by Jenn

I believe there is no difference how HOT flexwatt gets regardless of whether it's 11" or 3". The 11" just covers a larger AREA.

I use 11" flexwatt to heat a row of 20 gallon long tanks placed next to each other, and 3" on my racks. It works great.

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I assumed that the 11" flexwatt would get hotter than the 3", because the 3" is only either 6 or 10 watts per foot, and the 11" is 20 watts per foot.

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Originally Posted by Wh00h0069

I assumed that the 11" flexwatt would get hotter than the 3", because the 3" is only either 6 or 10 watts per foot, and the 11" is 20 watts per foot.

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You are correct. The 11" will get hotter than the 3" (6 or 10 wpf). I have never tried to plug each type directly into the wall, but if you do, you will see how hot each can get with unregulated power. With that said, I have my 11" on my hatchling racks set to 96 degrees, and the back of my tubs is normally around 91 degrees.

But wouldn't it take more power to produce a given amount of heat from a larger piece of flexwatt?

And, I was talking about the ambient temps inside the tub not the room Ed.

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Originally Posted by Jenn

But wouldn't it take more power to produce a given amount of heat from a larger piece of flexwatt?

And, I was talking about the ambient temps inside the tub not the room Ed.

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Hi Jenn, You are right about the ambient in the tubs running high and the hot spots running low.

Wh00h0069 asked,

How hot does 11" 20 watt flexwatt normally run?

I did a test for you.

With the heat tape running full power in a room that was 79 degrees, I was shooting temps from 107 at the coolest spot to 131 at the hottest. This was 11" flexwatt, temps shot directly at the surface with an infra red gun. The heat tape was uncovered and laying on a piece of pvc sheet. I let it stand about 20 minutes to stabilize before shooting temps.

I have a back heat rack with 11" heat tape that works just fine. I can maintain my basking area in the rear quarter of 12 qt tubs at 90 degrees in a room as cool as about 72. At that point I am sure the flexwatt is receiving full power from the t-stat trying to keep up.

I suspect the larger tubs may be a little harder to heat. How far from the heat tape are you measuring the basking temps?

One thing I would recommend would be to put some reflective foil behind the heat tape. That is between the melamine back panel and the heat tape, with the reflective side toward the heat tape.

I think you might be surprised at the difference this makes.