too much air ?

[caj]

I am building a incubator out of a full size fridge. I want to use a fan big enough to move the air from top to bottom. How do you tell if its too much. What will happen if there is too much air speed?

 

[PurpleChicken]

Too much air speed will cause high and low temp spots.

Put some spacers between the fan and the top. Then blow the fan up
so it disperses and goes down the sides.

A gentle circulation is all you need. You can test it by checking temps at each
height and then adjusting the fan speed/position.

 

[hinkjc]

Too much air can also cause the chick to dry out and stick to the egg during hatch.

 

[Intheswamp]

Quote:
Jody, could this mean that disconnecting the fan or either using a still-air incubator for hatching might be better than having a fan running? Seems the hot/cold spots incountered within a still-air might not be so detrimental at the hatching stage whereas drying out the membranes is detrimental. Just tryin' to figure things out before I try incubating this fall.

Ed

 

[AK_Button_Mama]

I have to say that the moving are is BAD durning hatch. I am dealing with it right now in the sportsmans I have all the bob eggs are drying out. I am about to build a hatcher that has a light in it and a thermostat and that is it no moving air in there for the hatcher!

 

[caj]

The fan I am using is a 4" high velocity from Wal-Mart for $7. I started out about 2" from the top facing up and the first shelf is 16" down from the top, second shelf is 24" down and third shelf is 32" down from the top. I had a 2.5 degree difference from top shelf to bottom shelf ( 16" ). I turned the fan to blow down and reduced the temp difference to about 1 degree. But now I am worried about too much air velocity on the eggs. I am trying to decide to put another fan in the bottom of the fridge or get some dryer vent hose and duct the air from the top to the bottom. I am using a repti-temp 500r thermostat and hair dryer for heat. It seems to be working well. The hair dryer only runs for 3-4 seconds and not very often. The temps hold good so far. Thanks for the help. Todd

 

[dancingbear]

Can you use a rheostat with the fan to reduce the fan speed? Or get a smaller, slower fan? I think your mistake was getting a high velocity fan, when you really need a very gentle low velocity fan. The idea is to have circulation, but not a breeze.

 

[caj]

the fan said high velocity on the box, but it does not blow very hard. I think the height of the fridge is too much for one fan unless I duct the air from top to bottom. I think I will give that a try tomarrow. I want all three shelves within at least one half degree.
Thanks, Todd

 

[pascopol]

Quote:
Also remember the larger fan running on slower speed is better than small fan running on high speed.

Larger fan will move more air smoothly and gently, small fan will cause turbulence (swirls of air) creating cold and hot spots.

 

[dancingbear]

Quote:
Excellent point, a bigger fan with lower speed would be much better.