Reptile & Amphibian Forums

Howdy-
I just built a melamine rack and have left the rear of the rack open. I was thinking of putting an 11" Flex-Watt attached to a 12" piece of melamine running down the middle of the rack. This leaves a 6.5" gap on both sides of the flex-watt. I thought maybe I could spare a little weight and let the tubs "breathe" a little. Question is, in anyone's experience is it going to be warm enough, too warm, or just right. I am housing Boas. The room is slightly heated due to the door in the small room being closed all day. Also, would anyone recomend a BAH proportional thermostat or any other brand? Any input would be appreciated.

Thanks-
Brett

you said your room is slightly heated,what temperature is that? back heat is not very effiecent and unless your room temp is around 75 degrees or higher i think your going to be disappointed,and leaving 6.5 inch gaps on each side of the flexwatt is going to add to the ineffiecenty.i built a 10 level rack with 3" flexwatt (6 watts per foot,belly heat) the total wattage is 170 watts,if i used 11" down the back the wattage would be 310.also with belly heat i can adjust the humidity in each tub by placement of the water bowl,not an option with back heat.i have found that belly heat is more expensive and less effiecent with less options.as far as thermostats if you do a search you'll find tons of info from past posters,i personally use herp powers from big apple and am pleased with there performance.have fun!

....my previous post should read: i have found that BACK heat is more expensive , less effiecent and has less options.

Thanks for the response. When I woke up this morning I was thinking about belly heat. So I am glad that you mentioned it. How would you wire that? It seems like it would be alot of connections. My room is about 84 during the day and drops down to 76-78 at night, but I was thinking belly heat might be a little better for the animals.

Thanks

You need to present the facts straight. You said your room is a little warm.. but 84 deg is not a little warm. You don't need any heat during the day. At night the rack can be heated by back heat, but you must cover those gaps with 1 1/2" thick styrene foam insulation. Cheap and easy.
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Mark

Belly heat may be overkill for an 84* room. But if the rack is against an outside wall the lower levels may not be that warm.

I actually don't like belly heat, at least not how it's utilized by most keepers. Back heat is less efficient but when utilized correctly it actually does a better job of creating a heated air-space, something more appropriate for Boas than a hot spot on the floor. But then again, with your room being that warm you really won't have to worry about a hot spot, so you really can go with whatever you feel most comfortable with.

But I digress. If you don't need that strip of melamine down the back for structural integrity (which you likely don't) then just use the foil-covered styrene insulation as a faux-back for the rack.

The foil-covered product is important - the shiny surface will reflect the predominately radiant heat rays produced by Flexwatt.

In fact some tests I've run recently lead me to suspect that the bubble/foil insulation that comes in rolls would be even better. Unfortunately I've yet to run these tests using FlexWatt so I can't whole-heartedly recommend that particular insulation. Besides, the styrene/foil stuff is easier to buy in small quantitiy.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

yes you would have many connections,two per level.i believe that's why many mfg's use back heat,much less labor intense.they can be wired in series,beanfarm.com has a illustrated guide on there web site.also with belly heat you can put in switches or wire different levels seperately so you can heat just the levels that your useing.84 degree room temp with belly heat is overkill? not at all,it just means you will use next to nothing in electricity.belly heat creates a "hot spot"?,only if you choose to make that spot hot,you can set the thermostat where ever you want.i have a back heated 6 hole rack that barely heats 3-4 inches "sideways",correct me if i'm wrong doesn't heat naturally rise???

Hi TWH,

I don't like it when flexwatt is used under the following conditions:

1) rooms with low ambient temperatures

2) underneath a plastic box with little or no air-space,

3) with a single layer of newspaper

4) far away from the water bowl

These conditions are far from the ideal way to create a heated air-space with a gradient for many species. Under these situations keepers often either create a very hot spot in one area to achieve suitable temperatures elsewhere in the tub, or simply heat that one small area and don't worry about the rest of the tub (which then tends to be too cool).

This is not appropriate for many species and for the same reasons that "hot rocks" are so strongly admonished for reptile use. Actually, hot rocks would arguably be better under these circumstances since the "rock" portion adds a lot of thermal mass to the environment.

Not to even suggest, however, that I recommend hot rocks.

>>it just means you will use next to nothing in electricity.

The most efficient way is not necessarily the best for the animals.

>>correct me if i'm wrong doesn't heat naturally rise???

I guess you are 1/3 correct. There are three types of heat movement. Convective, conductive, and radiant.

Flexwatt produces mostly radiant heat. Radiant heat bounces around like light rays and continues to do so until it is reflected in another direction or hits something that it can warm up. In the case of belly heat in cool rooms, a thin layer of plastic with little air space and a layer of newspaper does not provide much in the way of thermal mass for the flexwatt to heat up. If it did, more of the radiant energy would be converted to convective/conductive energy and heat the air.

To be completely fair, under my criteria above, Flexwatt may still not be the best choice. It would have to run hotter but it would be better suited to create a heated air space, provided the appropriate conditions were met.

So maybe my gripe is not with belly heat, but rather with keepers how blindly assume it's an appropriate way to deal with cool conditions.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

You are exactly right. IMO belly heat is often misused in this hobby, but often the snakes are tough enough to do well anyway.
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Mark

The reason why it ends up working under these conditions is that we're relying on the snake for thermal mass, especially with the heavy bodied ball pythons and such.

I just don't agree with this, at least in conjunction with belly heat.

I'm glad to hear I'm not alone
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

CH duece.........it wasn't that long ago you were a fan of belly heat,"who hath bewitched thee brethren"? (lol) have you ever put several thermometers with probes in a back heated rack? what i did with mine was to put probes on the flexwatt and then in 1 inch increments,if the room was not at least 80 degrees the temp didn't go anywhere near that which would benfit the snake.belly heat isn't perfect but it out performs back heat greatley.BTW in my rosy's tubs i put the small water container in front and then in the back over the flexwatt i put a small c shaped patio block,this keeps the tub evenly heated, i'm surprised how well this works.i think in cases were there are low room temps thermal mass would be effective in preventing cold spots.i haven't experminated with this to much,but something to consider.have fun!

>>CH duece.........it wasn't that long ago you were a fan of belly heat

Yes, and you e-mailed me about it privately, at least I believe it was you, when I made a post similar to my first in this thread. Maybe you never got my response.

Note that I've never said back heat was best under all circumstances.

I like belly heat when it is used properly. From my experience it is VERY rarely used properly. It is often used as a crutch to overcome less than ideal circumstances by herpers who just don't want to think about it.

I have taken temps in racks with back heat. But there was already a nice ambient temp and I was using a reflective rather than resistive type of insulation.

I do plan on running some more tests with various heat sources and different types of insulation. I'll try to refrain from further comment until I run them.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

Thanks guys...I appreciate all the input. I am going to try the one 11" strip back heat. My room is somewhat heated and I hope it will be ok. It seems like alot less wiring and work. If it doesn't work out I will re-route 3" to each shelf. Again, I appreciate all the help.

Brett

>>BTW in my rosy's tubs i put the small water container in front and then in the back over the flexwatt i put a small c shaped patio block,this keeps the tub evenly heated, i'm surprised how well this works.

This is exactly what most keepers should be doing... providing something (other than the snake) to increase thermal mass.

A small plastic flask of water would work great, as does your patio block example. Of course neither of these would work as well with a large snake that could push them around.

Another option I have though about is having a large piece of ceramic tile over the flexwatt. Then have the box slide on shims that are just a hair taller than the thickness of the tile.

This is also why back heat works so well in expanded PVC racks... it is just so conductive.

At any rate, sorry I forgot to comment on this earlier. I'm glad to see you're in the minority when it comes to improper use of belly heat.

Lastly, regarding the small rack you have with back heat. Try putting some heavy duty aluminum foil between the back of the rack and the heat tape. Preferably hanging a bit loose with a bit of an air space behind it. Not ideal, but it's cheap and should reflect some of the radiant heat back onto your snakes.

Shiny side facing towards the snakes. Use several regular sheets if you don't already have the heavy duty stuff.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

chris....thanks for the ideas on my 3/6 hole rack.i bought two of them orignally and was told by the maker that they would warm 13-16 degrees above room temp.i informed him my winter temps get down to 60,we both live in michigan.well to make a long story short they failed big time,at 70 degrees they could only raise the top hole 10 degrees.after many emails and phone calls he finally agreed to take them back,in route one of them got damaged and i told UPS i didn't want it back.but they returned it anyway so i repaired it and now am using it.it's made out of 1/4 inch dense plastic and the 11" flexwatt is calked to the back wall.it would be a major job to change it.when i went to the hardware store the other day i found a display of bubble wrap with a highly reflective metal foil on one side,they had a mitten like tester,when i put my hand in it within seconds you could feel it getting warmer.i think i'll cover the outside of the rack with this material,it seems promising.have fun!

I think I know what rack you're talking about. He's a good guy and I strongly suspect he fully believed he was telling the truth. But testing a rack in Room A does not mean it will work in Room B, even if the temperatures are the same.

Unfortunately, putting this reflective insulation on the outside of your rack won't be nearly as effective as putting it between the PVCX and the flexwatt.

As the radiant rays of the flexwatt pass through the PVCX they are converted to conductive heat. The reflective insulation won't be nearly as good at blocking this type of heat.

If you can buy this reflective material in small quantity, it is worth a shot. Otherwise, e-mail me with the dimensions of the rack and I probably can send you some.

I also have some cheap ideas for adding supplemental heat to the rack. We can go over that in e-mail.

And just to make sure we're talking about the same material, here's a shot of my herp room covered with it.

Is that the same stuff? I believe I'll have some leftover but I still need to cover the door.

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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

You mention wiring flexwatt in "series". If you meant that in the true electrical sense, Flexwatt should NEVER be wired in series. Per Calorique's documentation it should always be a parallel circuit.
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