Reptile & Amphibian Forums

I am building a rack and am going to install heat cable throughout, in a routered channel. I am looking for advice from people who have used it. What exact types were used? What control devices were used? Any other comments and/or suggestions?

I have been using that type of system for over a year now.

It has been working perfectly. I use the 3 watts per foot heat cable sold by Creative Pet. I think Zoomed also sells it, but is a little more expensive. It comes in a variety of lengths of cable and all you need is to plug it inline with a thermostat to control temps.

This heat cable is far safer than some of the other forms of heat out there.

How many passes under your rack containers are you making with the 3 watt cable? I'm thinking about going with the 15 watt per sq ft stuff, making one pass under the back of the rack in a routered channel and controling it with a proportional (voltage regulating) stat or a rheostat.

On a side note, as a prior poster suggested, I think the increased voltage drop in the longer lengths of cable is the reason for the watts per sq ft increase.

Safety is a major concern for me(I guess for all of us) Do you really think that the heat cable is one of the safest ways to provide heat?

Where would you place flexwatt? (in terms of safety)

Also The Flexwatt type heat pads made in Scotland that do not require thermostats?

I like to keep things simple where possible.

Thanks

Bob.

>>Do you really think that the heat cable is one of the safest ways to provide heat?

Of the electric forms of heat that can be used in a rack, yes.

>>Where would you place flexwatt? (in terms of safety)

What else is included on the list?
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Current snakes:

0.2 Gonyosoma oxycephala - (Silver/Yellow)

3.3 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

3.3 Gonyosoma janseni - (Black & Tan)

I meant that safety wise, if Heat cable were one of the safest ways to heat (Fire hazard wise, used in a rack or under a cage, plastic or wood given adequate air space/flow.)

Where would you rate regular Flex watt hooked up to a standard Thermostat?

And also the Flexwatt type plug in heat mats that are marketed not to need a thermostat if just a specific temp. hot spot is not critical to have?

For example:

Old fashioned plumber pipe cable being one of the worst fire hazard wise.

Modern heat cable being the best?

Thanks, Sorry for being a bit confusing. Bob

This is a difficult question. I'm not comfortable with saying that old fashioned plumbers heat tape is the most dangerous. Don't get my wrong, it probably is, but that data is biased by how that tape was used.

I've been keeping snakes since 1986 or so and can't begin to tell you some of the horror stories about how plumbers tape was used back then. I can tell you I was considered quite unique in having a 110V thermostat. It's not wonder there were accidents. With modern thermostats and understanding it's probably as safe as anything else.

Moreover, the apparent danger of that heat tape was biased by how it was used by homeowners. Sorry, but we really can't assess the danger of a product that's burned down a hundreds of homes, we need to limit the data to how/when things are used with herps.

If flexwatt were used in the same applications I'm sure there would be even more accidents.

I do suspect modern heat cable, the type designed for being run through potting soil or in grout for floor heat, will be safer.

But I won't go as far as to say "much" safer as it's still a type of electric resistive heat. I probably did say that in previous posts, but I'm not so sure that's fair.

With that said, my best guess of how these products rank in terms of safety.

1) Heat Cable

2) Wired/sealed heat pads (Ultratherm, Cobra, etc.)

3) Flexwatt

4) Plumbers heat tape
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Current snakes:

0.2 Gonyosoma oxycephala - (Silver/Yellow)

3.3 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

3.3 Gonyosoma janseni - (Black & Tan)

n/p

I agree that heat cable is probably safer than other forms of resistive heat, at lease of those that can be used in a rack.

I would route a grid system that will allow you to put as little or as much rope under any given tub as needed. Just use a little imagination, it will make sense.

There are the Zoo Med and Big Apple products. What I don't understand is the watts per foot listings for both products. Both of their 25 foot products are about the same, 1.7 and 1.9 watts/ft. respectively.

But then there is logarithmic relationship between length and watts per foot depending on the length of either product.

For example, the ZooMed 15' product is 1.3 watts/foot, the 25' product is 1.7 watts per foot, 50' is 2.2 w/ft, 100' is 2.5 w/ft.

A similar logarithmic increase is seen in the Big Apple Product.

The only thing I can think of to explain this is the non-linear relationship between watts and heat. For example, a 50 watt lightbulb does not give off twice as much heat as a 25 watt lightbulb.

So perhaps the longer products need more wattage to give off as much heat per foot as the shorter products? I don't know, I'm thinking out loud here.

In that case are we better off with two 25 footers rather than one 50 footer? Same heat, less wattage?
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Current snakes:

0.2 Gonyosoma oxycephala - (Silver/Yellow)

3.3 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

3.3 Gonyosoma janseni - (Black & Tan)

Chris your math is right but in addition I wonder if voltage drop is a factor? Where did you get the number for watts/foot.
If voltage drop is a factor your deciding to go with 2 25' vs 1 50' again would be more efficient. But on the other hand amps drawn would also be another factor, I don't think anyone has thought of.
Jeremy

Jeremy,

Just got off the phone with an electrical engineer friend. He made several good points.

First, he's about 95% certain than the products would have the same heat production per foot even though the longer ones have more watts per foot. He said part of that is the logarithmic relationship between wattage and heat in resistors (which was my theory), but also had to do with surface area in relation to wattage and voltage dropoff as you suggested.

But he'd need to run some numbers to be sure.

Off the top of his head he said it would probably make more sense to run two 11.5' cables instead of one 23' cable, for example, but that the differences would likely be trivial.

In terms of racks, there are probably benefits to running multiple cables per rack anyways, so that's something to keep in mind.

It also makes me wonder about my rope light. I have two different lengths running. One 12' and one 48', I believe.

Later today I'll take four measurements. Two near the beginning of each rope and two near the end of each rope. It will be different to see how close they are.

This is a slightly different situation than the cable since there are multiple bulbs run along the length. Not sure if they are a series or in parallel.
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Current snakes:

0.2 Gonyosoma oxycephala - (Silver/Yellow)

3.3 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

3.3 Gonyosoma janseni - (Black & Tan)

>>Off the top of his head he said it would probably make more sense to run two 11.5' cables instead of one 23' cable, for example, but that the differences would likely be trivial.
>>
>>In terms of racks, there are probably benefits to running multiple cables per rack anyways, so that's something to keep in mind.

With this I totally agree one would think you could almost run three one for minimum temp IE ambient heat suplement.

2 Hot spot day time
3 Night time drop supplement

I know you could do the same with two but I like the idea of a back up source. Only problem is thermostat control. Which bringd back to me plan I mention a few weeks ago. Total PC Control with the right setup a home Pc could control hundreds of probs and heat source's. Giving you minute temp changes across a broad spectrum. Better than mother nature.

One down side the engineering and programing would be long and tedious and really expensive.

One can Dream
Jeremy
Let me know what you find.

I was just checking on your heat rope theories regarding the different brands out there. I got mine at Big Apple but now I see they have a special sale going on. For any of you interested there is a Buy 3 get the third one for free offer. In my calculation this makes the cost per foot extremely affordable. I also checked out some of the other brands and they looks similar but I'm very happy with the consistency of heat across the rope on the Big Apple product.

The one thing that I saw another company do is list the total length of the rope but did not bother to list that part of that length does not heat. I was glad to see that Big Apple only lists the length that actually produces heat. I'm running quite a number of ropes on a single Herp Power Thermostat and they all seem to be running constant 92 degrees across the length.

Winston