New incubator problem

Hello, ive made an incubator from an old fridge, and i placed an heatingg cable on the back, and four cooling PC fans on the top...im getting the 5° of temperatura diferente between the top and the bottom, any advice?

Hey there,

I would love to help out. Please provide more information, the size of the fridge, how much heat cable you're running, thermostat/probe placement, and what you're using to measure the temperature.

A photo would be great too.
How long did you have it running before you took temperatures?
4 fans might be too much airflow?

4 fans seems like overkilled, I only used one.

My guess you have 2 fan flowing toward the top and 2 blowing toward the bottom?

If your temps are 5 degrees higher on the top and you have fan flowing air toward the top shut them down.

Ideally a picture of your incubator would really be best to see how the heat is placed and where the fans are placed.

You will have a temperature differential in your incubator which is ok (I have 2 degrees differential)

Here an old picture at the bigining of the construction, now it have a front glass. soon i will post some pics.
http://i1212.photobucket.com/albums/...oso/spacer.gif
http://i1212.photobucket.com/albums/...oso/spacer.gif
http://i1212.photobucket.com/albums/...82609434_n.jpg

i had only 2 small 5V fans but i think 4 would help with this to much heat on the top, but seems makes no diference. The incubator have 80/90cm high (34in). i use a cable with 50W on the back ( i tried all the back and then tried in the back but just starting in the middle and ending in the bottom and solve a little bit but not enough.

i use several digital probing thermometers, and some fish termometers on differente shelfs.
I use the thermostat probe in the middle but i tried in differente spots with no success.

That little mini fridge shouldn't be that much problem.
How long are you waiting for temperatures to settle?

Quote:

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Originally Posted by cris17

Here an old picture at the bigining of the construction, now it have a front glass. soon i will post some pics.
http://i1212.photobucket.com/albums/...oso/spacer.gif
http://i1212.photobucket.com/albums/...oso/spacer.gif
http://i1212.photobucket.com/albums/...82609434_n.jpg

i had only 2 small 5V fans but i think 4 would help with this to much heat on the top, but seems makes no diference. The incubator have 80/90cm high (34in). i use a cable with 50W on the back ( i tried all the back and then tried in the back but just starting in the middle and ending in the bottom and solve a little bit but not enough.

i use several digital probing thermometers, and some fish termometers on differente shelfs.
I use the thermostat probe in the middle but i tried in differente spots with no success.

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The picture is not helping, you need a current picture showing heat placement and fan and at that size 4 fans is overkilled. I run a LARGE fridge incubator with 1 fan, hand have run large coolers (36 inches) with no fan at all.

here some update pictures.
I'm trying with and without water bottles, and with/without PC fans.

http://i1212.photobucket.com/albums/...o/DSC05362.jpg

http://i1212.photobucket.com/albums/...o/DSC05363.jpg

http://i1212.photobucket.com/albums/...o/DSC05361.jpg

http://i1212.photobucket.com/albums/...o/DSC05360.jpg

I would eliminate the water bottles on the shelf .... they are more than likely restricting the air flow you are trying to create with the fans

Heat rises. Since your fluctuation is at the top of the bator why don't you consider centering the heating element a bit more? Maybe even consider heat tape over the cable? Very nice work though, congrats.