Reptile & Amphibian Forums

I have made a home made incubator out of a coke fridge and need to install a computer fan. I would appreciate any suggestions.

Thanks,
Kyle

I found a 4" fan at Radio Shack and I installed it at the bottom of my incubator, and it worked good for me last year.
Good luck with it, Mike Derks

I'm not sure which is best, but for an incubator that tall, I think it would be best to use two fans.
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Jay A. Martin
Jay Martin Reptiles

Not the best picture but along the left side you can see my air circulation system. It's a tube of PVC with a 12 volt DC fan from an old computer inserted in the top facing the right direction to work with natural convection and pull air down the corner. The wire cage on the bottom keeps space for air to escape out. Be careful to wire the polarity of your AC to 12 volt DC converter to the fan such that it spins in the intended direction. My first attempt was a curved blade fan and when it spun backwards it tended to straiten the blades out until they eventually rubbed against the housing and caused the motor to burn out (hence the baking powder to get rid of the smoke smell, probably neither are the best for the eggs).

I also tried to get fancy and placed a small outside air hole through the outside of the fridge into the big air down pipe near the bottom and another hole into just the fridge near the front bottom. Each hole was lined with a piece of the big aquarium tubing glued in place to keep the insulation from moving to plug the hole. I also glued screen over the outside of the holes to keep flies from getting in. The theory is that the Bernoulli effect of the air moving by the bottom of the tube should suck outside air in right before it hits my heat source in the bottom. That heat source by the way is about a foot of 11" heat tape sandwiched between two big ceramic tiles and held off the floor by four small blocks, it really doesn’t take much to heat a well insulated freezer/fridge. I've never done a smoke test to see if air really circulates the way I think it will. I did find that I needed to insulate the bottom shelf heavily because the radiant heat from the heat source kept it hotter than the top shelf. Apparently the fan did a good job of pulling down the natural convection hot air you would expect to gather at the top.

I also suspect you would not want a fan with much of any vibration as that might be bad for the eggs. Maybe some sort of system to isolate the fan from contact with the egg shelves.

The 4" radioshack fan works well. I use 3 of them because of the size of my incubator.
You can see them in the bottom of the incubator in the photo.
Becky

That looks like a pretty nice set up. Do you mind me asking how much time and money was spent there.
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Chris Farmer
Explicit Reptiles

Thanks, it was quiet a job building it. I would have to estimate about $400. It took a full weekend to build and then a couple of evenings to complete all the electrical. I am still hiding the Home Depot bills from my husband. You could probably build it alot faster if there were two adults. It was just myself and my 10 year old son building this monster. Those full sized sheets of melamine were horrible to handle, they barley fit in the back of the truck.
But it came out pretty good, I am proud of it.

Just curious what kind of heating element is in it and how stable are the temps in that large of an incubater? I'm in the process of building an incubator and keep going back and forth from the refridge style or a custom wood/melamine.
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2.3 het pied (RDR, alan bosch x 2, BHB x 2)
1.1 het albino (ben siegel, gulf coast)
1.2 het citrus ghost(gulf coast line)
1.0 citrus ghost (gulf coast line)
0.1 graz pastel female
1.6 05 normal bp's
0.6 04 normal bp's
2.5 adult normal bp's (some need breeding to see if norm)
4 various corns
0.1 brazilian rainbow boa (alan bosch)
1.0 american pit bull terrior
1.1 taco dogs (ankle biters)
1.0 grey cat
1.1 bearded dragons

a BAD dog is MADE not bred, support the American Pit Bull Terrior as the greatest breed of dogs on Earth!!!!!

I have the 3 fans on the bottom shelf of the incubator. They are drawing air down and blowing it over three 60 watt lightbulbs that are located in a chamber below the fans. The heated air is then forced up thru the false back and then forced down into the egg compartment, and over the egg boxes.
I hope I explained this correctly.
I have wired my lights into a thermostat and the fans run all the time.
I have been very happy with the results of my incubator. I have about a 1-2 degree difference from the bottom shelf to the top shelf. It's very close and stays very consistant. I like building my own incubators because you can build it to what ever size you need. They are heavy, make sure you build it on good quality heavy duty casters.

I completely understand how you made it. I thought of a similar design but wasn't sure how consistant it is. The design I've been thinking the most about is by building an internal box that is framed on the outside with another box built to that. In the space between the boxes filling with expanding foam insulation. The heating element will be 2 lengths of 11" heat tape running equal distances from one side (picture 11" of bare wood then the tape then another piece of heat tape followed by bare wood). In each rare corner of the internal box placing a fan inside a piece of 4" pvc pipe to circulate air from top to bottom. I will probably use 1/4" plywood for this to keep the weight down and will probably laminate the exterior box for curb appeal. The thermostat will be a helix propertional. The only thing I can't decide on is what to make the front out of. I've been thinking 1/4" plexi for it but not sure how this will do with heat loss or consistancy. Let me know what you think.
Josh Hutto........JKReptiles

It was sooooo much easier when all I had to incubate were a few clutches, lol.
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2.3 het pied (RDR, alan bosch x 2, BHB x 2)
1.1 het albino (ben siegel, gulf coast)
1.2 het citrus ghost(gulf coast line)
1.0 citrus ghost (gulf coast line)
0.1 graz pastel female
1.6 05 normal bp's
0.6 04 normal bp's
2.5 adult normal bp's (some need breeding to see if norm)
4 various corns
0.1 brazilian rainbow boa (alan bosch)
1.0 american pit bull terrior
1.1 taco dogs (ankle biters)
1.0 grey cat
1.1 bearded dragons

a BAD dog is MADE not bred, support the American Pit Bull Terrior as the greatest breed of dogs on Earth!!!!!

Sounds very similar to my design. The plexi seems to work fine, but my reptile room is always about 77 degrees. I like the light bulbs for heating better than heat tape..just a personal preference.
Becky

Do you use a proportional thermostat and if so how does it work with the light bulbs (do they tend to flicker and burn out)?

Not including the thermostat I think I have less then $10 in my incubator (broken freezer, fan salvaged from an old computer, 12V DC power converter salvaged from an old toy). But a nice proportional thermostat is the big expense.

I actually have a double thermostat system. I have a Helix as my main thermostat and then I have a Alife thermostat as a back up, just incase the helix should ever fail.
The light bulbs flickered a little at first until the temperature flexuations were controlled and the correct degree was reached. They are consistantly on now, just a continual glowing. They arn't very bright I think I replaced 1 of the three light bulbs last season. When the one light bulb burned out the other two bulbs just worked a little harder to keep the correct temperature. It's a great system.
I really like the fact that I can see in it without opening the doors.
I had debated about converting an old fridge, but for me this was where I had more experience. This is the second incubator that I built, I out grew the first which was a bout 1/2 the size of the monster. I built this one large enough that I shouldn't outgrow it for a long time.
Becky

I bought a radioshack computer fan and installed it yesterday