Reptile & Amphibian Forums

I am looking to either purchase or make a rack system for my colubrids with Flexwatt. Which type of mounting is more effective; back or belly? basement they are in is 65-69degrees so I neem to make sure they have a sufficient hot side.

I can't see the back heat working too well, but it must serve it's purpose since people use it.

btw, does anyone have any rack plans or know where I can find them. I would use 28-32qt containers.

thanks
jeff

If you like wasting electricity and sick animals, go with the back heat.

I would need some containter dimensions and what kind of meterials you would like to build the racks out of. I did a coupel quick layouts for a friend of mine for a fish wall that held some 55g's and a 75

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Nick and Drayko

>>I am looking to either purchase or make a rack system for my colubrids with Flexwatt. Which type of mounting is more effective; back or belly?

Belly heat is more efficient, but not because heat rises. In fact only convective heat rises and it is nearly impossible to create a convective current in a typical rack setup.

Flexwatt produces radiant heat which moves in a straight line parallel from it's source until is is reflected or absorbed. In a typical rack setup with belly heat that means either up & into the box or down into the shelf below. In the latter case, that simply means the shelf is heated up and becomes a secondary radiator for the heat source, in other words there is more thermal mass.

Also, in a typical rack w/belly-heat setup, a large portion of the box is heated up which also increases the thermal mass.

With back heat the heat either moves into the back of the tubs or escapes out of the back of the rack. Also, with back heat there is less thermal mass to be heated up.

However, thermal mass can be increased and the back of racks can be covered with reflective insulation, both of which duplicate or even improve on some of the advantages of belly heat.

Which begs the question if there is any advantage to back heat?

In my opinion, yes. In a cold room it can be very difficult to create a proper thermal gradiant without flexwatt needing to reach very high surface temperatures. This holds true whether back or belly heat is used.

The one advantage of back heat over belly heat is that it is very rare for any surface of the tub to reach uncomfortable or even dangerous temperatures. This is actually pretty common with belly heat. One exception is the heating design of the new Vision racks which are just really, really slick. As far as I know it's not been duplicated in any other commerical rack. But its merits would be hard to duplicate in a DIY rack.

With belly heat if you set the Tstat probe to control the hot spot the opposite end of the tub often does not get warm enough. Conversely, if you set the Tstat probe to control the cool end then the hot spot can become dangerous for the snake. At least in cool rooms.

Also, back heat is less susceptible to heating accidents that can arise from accidental or forgetful shifts in the placement of the Tstat probe.

Lastly, I'll comment that the most efficient way to heat a home is with radiant heat sources either mounted on the ceilings or upper walls of a home. If belly heat were more efficient then we would expect floor radiant heat to be more efficient in homes. Yet, it is not. Now there are many reasons for this that I won't get into, but its still interesting information.

>> ... basement they are in is 65-69degrees so I neem to make sure they have a sufficient hot side.

How many racks/snakes will you be keeping? How large will the basement room be where the rack(s) will be maintained?

It may actually be prudent for you to heat the room, at least slightly. Remember that room heat is more efficient if you have a medium to large collection. I used to keep the equivalent of sixteen, 25 gallon tanks in a 7'x7'x8' room. Without heat I would have need about one 60 watt bulb per tanks, or about 960 watts.

But with my oil-filled radiator heater set at 600 watts I was able to heat the entire room. And the heater rarely had to run to heat that small of a room. I only needed small amounts of supplemental heat for each cage, not 60 watts. And I could have kept a heck of a lot more than 16 tanks in the room.

>>btw, does anyone have any rack plans or know where I can find them. I would use 28-32qt containers.

I always recommend finegtps.com and arbreptiles.com. Between the two you should be able to come up with a design that works for you.

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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

2.2 Gonyosoma oxycephala - (Green)

4.3 Gonyosoma janseni - (Black)

Until recently I was housing a friends snake collection. He had a melamine rack with an open back.

I took that rack and one strip of rope light across the back of each tub. I then stapled a piece of Reflectix to the back.

Without even bothering to tape of the sides or anything it keep the back of the tubs 5*F higher than the fronts. But it was a heated room.

My friend now has the rack back but it's in a cool room. I just got off the phone with him. He taped up the sides and the tubs still have a perfect thermal gradiant.

I really believe the key is thermal mass and reflective insulation. Rope light has decent thermal mass due to the PVC casing and Reflectix blocks 97% of radiant heat.

Essentially, the back of the rack has been turned into a Radiant Heat Panel.
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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

2.2 Gonyosoma oxycephala - (Green)

4.3 Gonyosoma janseni - (Black)

Way in the back left of this picture is the rack I'm talking about. You can see the Reflectix poking out of the sides.

The Reflectix was so loosely attached the rope light was poking out of the sides.

My friend took that rack back and folded the Reflectix over onto the sides and taped it down. This rack is now heated fine in a cold basement. Again, it's the thermal mass of the PVC casing and the reflective nature of the insulation that makes the difference.

Same thing could be done with flexwatt, expanded PVC sheet, and Reflectix. Again, main advantage over belly heat is probably safety for the snakes.
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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

2.2 Gonyosoma oxycephala - (Green)

4.3 Gonyosoma janseni - (Black)

I second what Chris has said. It is highly recommended to heat the area not only the rack. If you leave the area unheated you will have to run the heat tape at a much higher unsafe level to attain a proper hot spot while still having an over all cold tub.

If you heat the area I would go with back heat if you go with a completely enclosed tub rack style. I build my racks usually 2" deeper then they need to be for the tubs and snug enough that there is a minimum of open space around the tubs to the front. This allows the area in the back of the rack to become warmer along with the tubs which helps keep it warm. I won't use belly heat in tub systems due to the high amount of heat tape required and the more heat tape wired in line means more chance for one or more pieces to go bad. (Plus heat tape seems to vary in surface temps when you measure a strip as much as 5 degrees with personal tests. And this is all in one single strip.)
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Randall L Turner Jr.
www.aircapitalconstrictors.com

Agreed. A oil-filled raditor pluged to a T-stat works great. I have a room temp abount 65degrees. With the oil heater set at 75degrees, back heat on my racks works great. Flexwatt set to 90degrees, I maintain 82-85degrees in back of tubs at all times.

.........folks,please try this and post your results:take 5 or 6 thermometers with probes and take the room temp,temp on the back heat tape,temp on the back of the tub then at one inch increments towards the front of the tub.i did this and was blown away with the results i'd like to see your numbers.

.........a 10 level rack with belly heat.i routed a shallow channel for the 3' flexwatt,i then covered the channel with metal tape and heat tape on top.the back of the rack is covered with reflix insulation,it works great.in a cool room you can take out a tub and place your face in the opening and FEEL heat.i'll be useing reflix in all of my new racks.

>>.........a 10 level rack with belly heat.i routed a shallow channel for the 3' flexwatt,i then covered the channel with metal tape and heat tape on top.

I'm confused, you have a layer of heat tape, a layer of foil tape, and then another layer of heat tape?

>> the back of the rack is covered with reflix insulation,it works great.in a cool room you can take out a tub and place your face in the opening and FEEL heat.i'll be useing reflix in all of my new racks.

That's really the key. With Reflectix you don't slow down the loss of heat, you outright reflect it back. I'm glad the rack is working out.

Is this the hatchling rack we discussed via e-mail?
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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

2.2 Gonyosoma oxycephala - (Green)

4.3 Gonyosoma janseni - (Black)

..........metal tape on routed melamine then heat tape on top of metal tape.

they both work but it really depends on where you are going to install the racks and what you plan to keep in them. I used 4 inch flexwatt, belly heat, in a rack that I built out of maple plywood. It worked well but direct belly heat can cook your snakes if your dimmer, thermostat, or rheostat fail. It has been some time since I have read a post about this but a few years ago it was fairly common to hear of a controller failing. If you install belly heat take the time to router a groove in the shelf so the boxes do not slide right over the flexwatt. I believe that this is one of leading causes of flexwatt burning out. The plastic surface / insulation gets scratched.
As far as back heat, I have 4 small racks that use back heat. No problem getting the temps up into the mid 90's for my balls. However, if the room is cold or the racks are up against a cold wall, near a window, etc. they tend to lose heat. This last winter in So. Cal. was very wet, cold, and long. I had so much problem trying to control my evening temp drop and bring the temps back up during the day that I had to install 2 inch rigid insulation on the backs of the racks. On the two that have a side facing a sliding glass door I had to install 2 inch rigid insulation on the side facing the glass. The insulation resolved the problem. The room the racks are in has ceramic tile flooring. Very nice during the summer because it stays cool. It also cooled the racks from the bottom. I built a small wooden base and set the racks on top of this. These racks worked fine in the previous years. The unusual winter made a difference as did a major change in my collection. I moved out several colubrids and brought in more balls.
Just sharing my experience with both types of heat.

gradually got cooler as you worked your way forward, that would be great. But there isn't such a heater. With Flexwatt, you get a hot spot over the tape and then an immediate cooler spot as soon as you are off the heater. There is no inbetween. Well, you can approximate a gradient with heat rope, but it is awfully time consuming. Point is, a hot spot surrounded by cold cage is not a good environment. Things that can help are increasing the room temp or else lots of insulation or Reflectix in or around the rack.

My room is not heated. Even still, I find back heat to be effective and safe. To make it effective I had to insulate like crazy (and it sounds like Reflectix ala Chris Harper would have been a better choice) but it works. No runaway hot spots, and no hot-spot/cold-box syndrome. Plus, there is a more gradual temperature gradient and not a drastic "heat/no heat" one.

Good luck,
Mark

...using back heat.

Chris, your rack is exactly what I plan on making. I have Kings and Corns. The room is fairly large and I will probably have 15-20 animals max.

Couple more questions
1. Where can I get Reflectix?
2. Any good recommendations for an oil heater?

thanks
Jeff

>>1. Where can I get Reflectix?

I bought a 48"x30' roll for about $35 at Menards. I have also seen it at Lowes. But if you're just using a little bit, you can buy it in bulk at some ACE Hardwares.

If you do buy it in bulk you can line the room with it. It really helps, even if the walls are insualted.

>>2. Any good recommendations for an oil heater?

Get one with 600, 900, and 1500 watt settings.

I do recommend running it through a thermostat for safety.
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Current snakes:

1.1 Gonyosoma oxycephala - (Silver/Yellow)

2.2 Gonyosoma oxycephala - (Green)

4.3 Gonyosoma janseni - (Black)