bar fridge.

[K1LOS]

Alright, after much searching i now have 2 bar fridges ready to be converted to incubators. One of them still works, so i think i will just keep that as a fridge.

I was planning on having it heated by lightbulbs, any opinions on this? I thought i would do 2 bulbs, one at the top back wall, and one at the bottom back wall. I would have to experiment with what wattage to use.

I'm still deciding on which proportional thermostat, its a tough call. I want to save money, but i don't want a piece of junk. Do i have to get a Helix or a Herpstat or the like, or can i get something from Rona? I want the digital display for the thermostat on the outside so i don't have to open the incubator to check the temp.

I also want a small indicator light on the outside so i know how often the bulbs are on (heating). Not sure how i'll do this, I imagine it would be a small LED or something.would i not have trouble wiring bulbs of varying wattages in series? Any suggestions?

I seem to be getting mixed opinions on fans, will i need one or not?

This will be a multi-prupose incubator. Currently i am just producing gecko eggs, but the beardies are coming of age, and i plan on getting some snakes (species undecided still) in the near future.

Alright, so thats what i'm thinking. What do you all think about that? I wanted to get some advice from the more experienced before i went and wasted a lot of time and money. Any input is appreciated. Thanks

Geoff

[mykee]

If you plan of produced at least a couple of hundred dollars worth of stuff in your incubator, I would recommend shelling out the bucks for a Helix. I would also recommmend heating your fridge with heat tape rather than light bulbs.

[Stockwell]

Don't use light bulbs.. they burn out or pop with voltage spikes, plus its too much heat in one spot and they use up valuable space. Use Flexwatt, power resistors, or order the element that Hovabators uses.. I've used all 3.
You'll need only about 28watts for a standard bar fridge.
I made one for Corey Woods using my own controller and a power resistor, and a bar fridge and that's all it consumes.. You need only 5 to 10 watts per cubic foot of volume to raise temps 20 degrees above an ambient of room. 70 to 90 equals pythons.

[K1LOS]

How much is the Helix? What heat tape should i use, 3" or 11", how much do you think i would need? PCPC is still the only place in ontario i know of to get it, does anybody know somewhere closer to ottawa?

Any electricians out there that know how i can wire up that indicator light?

Thanks

Geoff

[mykee]

Helix: $220. Heat tape: you'll probably need close to 10 feet of the 11" stuff ($70-$90).

[K1LOS]

10' for a bar fridge? I don't think i could even fit that much in there! Can you explain please.

Geoff

[Stockwell]

You wont need that much. Calculate the cubic foot volume. LXWXH
Once you know the internal volume multiply by 10 watts per cubic foot. Then the heat tape you'll need depends on the watts per foot of the heat tape... 11 inch is 20w/F, 4 inch is 8w/F
I'd use a couple strips of 4 inch across the bottom and up the sides as far as needed to give the desired watts. Work out the number of inches of heat tape and divide by two, and install 2 equal lengths and wire them both in parallel.
The reason I'd use two lengths of 4 inch rather than one smaller one of 11, is so you can position the fan between the two strips to move the air across it evenly.
Like I said, I made one of these for Mr. Woods, and it only consumes 28watts, and controls at 90F just fine. Its just under 3 cubic foot of internal volume.
Having too much heat will cause over-shoot, and having too little means it takes too long to reach setpoint and too long to recover from having the door open..
Ideally you want a heat- to setpoint time, of about 15 to 30 minutes from room temp ambient of 70
You're going to need roughly 2 pieces of 4 inch, 2 feet each in length. That will give you 32 watts which should be loads for a standard bar fridge

I actually much prefer to build my own enclosures out of wood. That way I make the incubator to fit the space I have and to fit the containers I like to use. There is no good reason to use bar fridges... Guys think you need an insulated box, but that is simply not true. If you have a good controller, you don't need insulation because any losses will be made up almost instantly. Plus power is cheap. So you use a couple watts more for uninsulated incubators, its insignificant.
I build mine like this, with sliding plexiglass, so I can see whats going on without opening a big door and losing all the heat(which happens with bar fridges.
http://www.ssnakess.com/photopost/data/504/18011590Incubators03inprogress-med.jpg
Below is a closet full...these were made to fit the space
http://www.ssnakess.com/photopost/data/500/1801incubaotrs04-med.jpg

[K1LOS]

Thanks for the explanation Roy.

I'm not the greatest carpenter and i got the barfridge for free, so i will still go that route. Insulation must make some sort of difference in stabilizing the temperature, no?

I do like being able to see inside without opening the door. I noticed in the classifieds right now there is a converted bar fridge with a plexi window built in. I might try that one day when i get my hands on a dremel.

I have heard you have lots of experience in this. Can you tell me why some people are against fans? It just seems logical to me, but i have little experience with incubators. Thanks

Geoff

[Stockwell]

Insulation of the box is over rated by herpers, and comes from the days when only slow thermostats were used. There is nothing wrong with insulation, but you have to consider the thermodynamics of the entire system, including the egg media and the electronic controllers ability to adjust to small temperature changes.
Certainly with a crappy bi- metal type thermostat an insulated box is a good idea because the thermostat wont be able to respond quick enough to overcome minor losses of heat. Bi-metals are slow to respond.
This is not the case with electronic controllers with small remote sensors which can respond to minute temp changes in a few seconds
The egg box , essentially sealed, with a good base of moist vermiculite, or even water if you're using that method, is in itself a very stable mass, and it would take several minutes to both increase and decrease the temperature of that mass.(providing the lid is on)
By sensing the air temperature outside the egg box and switching the heat on and off based on that temp, you are controlling on the smalles mass that changes temp first and that is the correct way to do it. Never make the mistake of putting the controller sensor in the egg box.
The egg box in a well designed system, generally sees next to no change in temperature if you're controlling on the air surrounding it.
Air temp changes much quicker than anything solid or wet with more mass.
If your temperature controller has a very tight differential(on-off swing), or a proportional output, it will be directing power to the heater very frequently to compensate for minor changes in air temp...
This high duty cycle isn't possible with old fashioned thermostats, but is one of the beauties of using electronic controllers.

Adding insulation, isn't a bad thing, but basically only decreases the duty cycle of the controller and saves power by requiring the heat to be on less. This is really not an issue , however one benefit is during a power failure, insulated incubators will not drop in temperature as fast as basic boxes like my designs.
Now I have inverter backups for mine, so I don't worry about that, but I'd probably still toss a bath towel over them in the event of a power failure.
Some guys like to load the bottom of incubators with bottles of water... This makes good sense and has much the same effect as insulation because it adds a huge volume of mass which will take a long time to heat up and cool down. This will stabilize the entire temperature mass inside the incubator cavity, but it will also greatly increase the time it takes to reach setpoint when you first plug it in.
But I don't bother with this adding water.. Water is heavy and dangerous around the electrics which I always put in the bottom.
Once again, keep in mind that while a huge mass of water will serve to stabilize the temperature, it won't do that better than a good quick responding controller will. So in my estimation, it isn't worth the bother.
The hassle of adding insulation or mass to the incubator needs to be weighed against the real improvement in temperature stability.

Fans are an important aspect to even disturibution of heat in an incubator, and all my designs utilize fans. This isn't to say your incubator wont be just as successful without one. However,without fans you tend to have more internal differences ie hot and cold spots. This of course is theoretical and isn't always a concern.
The only problem with fans is that they produce heat themselves, and they tend to dry out the air since circulation will greatly increase and more air will be exchanged and lost through cracks or openings..
Now, fans must be properly spec'd and most people don't know which one to buy or what speed it should move, and those that complain about fans have generally had bad resutls with ones that produce too much heat or move at too high an RPM.

Fans with low wattage and low CFM(cubic foot per minute) are the trick here, and they probably wont be the one at the local Radio Shack.
Some fans consume 12 watts or more... In a small incubator that could respresent half your heating power, adding an uncontrolled heat soure. This can and has resulted in over heated incubators.

Its best to run fans constantly and not switch them on or off with the heat cycle, but to do so, fans with low wattages around 7 or less must be selected. You also want to only stir the air, not make the incubator into an air tunnel.. So CFM should be selected for the size of box. 19 to 32 CFM is the range I usually use for 2 to 4 cubic foot units. The smaller the box , the lower the wattage and the lower the CFM.
In really tiny Hovabator size incubators it can be tough to find fans small enough and DC fans might be required but then you need a DC supply. In really tiny units, its probably safer to not bother with a fan, rather than risk putting one in that is too hot and moving at too high an RPM.

I don't like fridges because, they have no window, and the pop can thing on the door is in the way, and they rarely fit where you want to put them or hold your favourite Rubbermaid. For me they are more trouble to convert and have really no aspect to make the effor worthwhile
For this reason, I prefer to build my own box... I stain and varnish it, so it looks the way I want it to look, I make it the size I want, and I put sliding doors in, lights etc.

[Stockwell]

One last thing... Before Jeff Favelle jumps in. :)
Many herpers have great success using very simple "wet type" incubators utilizing styros or coolers containing water and good quality aquarium heaters.
Many of the theories and principles I discussed above, still hold true with this technique... A heated body of water, has no hot spots,thus requires no fan, and also has great mass which serves to stabilize temps.
Water systems have long start up times, but once up to temperature can be very stable if you don't mind dealing with water , the mess, the weight and increased shock hazard that comes with a wet system.
Water type incubation systems can and do hatch hundreds of eggs.

[Jeff_Favelle]

For gecko eggs, I'd go with the dry system that Roy has posted pics of. It will work wonders and that's that. No sense messin' around with what works.

[K1LOS]

Will the dry system work with kingsnake eggs as well? I am pretty sure they will become my future project.

thanks a lot for all the pointers everyone (Uncle Roy especially), you are going to save me the time, trouble, and money of having to redo all of this in a year!

I haven't started the incubator yet, i have to finish a cage up first, then i will get to messing with the incubator. So i have lots of time, the more opinions and pointers the better.

Roy: Where do you suggest i find one of these low watt and low cfm fans? What are they marketed for?

Jeff: do you exclusively use the styrofoam cooler w/ water method? You are a semi-pro breeder, correct? must be a lot of coolers around your house!

Thanks everyone,

Geoff

[HumphreyBoagart]

Roy,
Just wondering if this is correct before I go building something with or without a major componant...
So this incubator has no water in the bottom? Just the damp vermiculite/perlite in the containers? Right?
Hence the name dry incubator?
Thanks,
Hump.

[Stockwell]

Geoff, my dry incubators hatch everything I work with(look in my gallery) and that includes a wide variety of parchment shell layers.. Kingsnakes, Milksnakes,Greybands, Ratsnakes, Pythons, Skinks, Geckos etc.. They hatch them all. I also use my incubators as baby raising nurseries. Right now they are full of baby Solomon boas and hold back sand and rosy boas.
Incubators also serve as infermories for sickies, and I design mine to be adjustable right up to 100F, just for that reason.
On top of that fan blown dry incubators also thaw out rodents...pronto...:)
I use NMB brand fans and buy them from Newark Electronics. I have posted on this before giving part numbers. One I often use sits right in front of me on my desk, so it's Model 3115FS-12W-B10
It's only 3.25 inches square, and consumes 4.5 watts generating 22CFM, I think. It's suitable for incubators in the 2 to 3 cubic foot range and can be seen in my posted pics above
You can buy the fans over the phone with a credit card, or possibly on line as well www.Newark.com
Do a search on "incubators" or "Newark" and see if you can find my past post with part numbers.
Here's the thread with some part numbers
http://www.ssnakess.com/forums/showthread.php?s=&threadid=42832&perpage=15&pagenumber=2

[Stockwell]

Originally posted by HumphreyBoagart
Roy,
Just wondering if this is correct before I go building something with or without a major componant...
So this incubator has no water in the bottom? Just the damp vermiculite/perlite in the containers? Right?
Hence the name dry incubator?
Thanks,
Hump.

Yes, that is correct. A dry incubator is a controlled heated air space. It's dry so there is no water, to make a mess or corode instrumentation.
The humidity is controlled automatically in separate closed egg containers which are then placed into the controlled air volume.
The egg containers can then hold whatever type of substrate you prefer either moist vermiculite, perlite, spaghnum moss... even water, although that represents a spill hazard and makes rubbemaids awfully heavy.
I generally use moist vermiculite in my boxes, but have used everything I listed... It all works.
I even hatched some gecko eggs on marbles piled in water one year just for a laugh.
I might add that dry type incubators are also ideal for hatching dry shell type eggs like Frog eye geckos, Crocodile geckos etc, by simply putting them in containers holding only dry sand.
I've had occasions where I have both snake eggs and frog eye gecko eggs in the same incubator.
The only difference is the substrate and humidity inside the individual egg containers.
This is an advantage over wet incubators where the entire air volume is at a high humidity since ther is open water.

[Jeff_Favelle]

Jeff: do you exclusively use the styrofoam cooler w/ water method? You are a semi-pro breeder, correct? must be a lot of coolers around your house!


I use ONE large incubator (4 feet x 3 feet x 3 feet) for the pythons that is a custom-made wood box, insulated on the inside, lined with 3 layers of plastic poly, two 250W submersible heaters, connected to a Helix DBS-100. I hatched 7 Jungle Carpet clutches in 2004 with this incubator and 9 Ball Python clutches. The incubator can hold up to 30 clutches of python eggs at any one time.

My Honduran incubator is the same deal, but on a smaller scale. It can incubate about 18-24 Hondo clutches simultaneously.

Cheers!

[HumphreyBoagart]

Awesome thanks for the help Roy!
Much Appreciation! : )