Please help! How much of a temperature variance is tolerable?

[Engteacher]

Here are the modifications I've just made....

I moved the thermostat from the wall of the igloo cooler to the wood frame of my egg turner and didn't drive the screws home. Instead, I left about 1/2 inch and pullet the thermostat out away from the wood for air flow. It's also further away from the bulb now, so we'll see what that does.

I have aluminum foil on hand, but I want to see what a difference this makes first.

 

[eggsellentfarms]

The suggestion to move the thermostat closer to the heat source sounds like a good idea. make sure you space it off the wall 1/2 inch or more. I mounted mine to a little chunk of 1 x 3, which in turn is mounted to the wall. Also, in my incubator I have a temp probe inside a ziploc bag filled with water in the middle of all the eggs. Even though the air temp fluctuates between 96 and 104, the probe to simulate the egg temperature stays between 98 and 101. I also have a full water bottle sitting under the eggs to act as thermal mass and stabilize the temperature a bit. I just had my first hatch which was a little disappointing, but right on time. I would like to find a thermostat with an ease of installation and low price like the water heater thermostat, but with a tighter temperature range. I don't know if I can blame the low hatch rate on the water heater thermostat just yet though, because several times during the first week I accidentally left the light on in my incubator and the temperature got a little high.

 

[Engteacher]

After two hours, we're still seeing a 6 degree temp swing and it's running a bit hot. We'll leave it over night and then try to turn it down a bit right away tomorrow morning. I put a silicon filled "egg" inside with a probe that we had already double checked for accuracy with the other thermometer. It's running at 94 degrees, but I'm sure it hasn't cured yet. Once that happens, it might read something a bit different.

Do you think I should add water yet? I have sponges in position and my humidity is just 20%. Does anyone know what impact will humidity have on my air temperature?

 

[Delight in Dominiques]

Just have to put this in to complicate things even more. A while back I seen in the forum where a bator maker used a wall thermostat. I was testing out my own homemade bator and I found the water heater thermostat was way too off for keeping a close range in temps. Tried every thing that was on here. spacing closer. holes you name it. The disk in the water termo relies on radiant heat. With air it will take time for the disk to cool or expand. I rigged up the wall thermostat and I have been running it now for the last three weeks Max temp 100.4 to min temp of 99.2. Best I could zero it in. The only differance between the water and the wall thermostats are that you will have to use a 12 volt power supply (already using that to power your cpu fan) runing it through a single pole single throw relay (should be avalible at any auto parts store). The idea that the wall thermostat would lets say act like a light switch. The metal coil on the thermostat shrinks and expands with the temps, moving the mercury bulb which throws the 12 volt power to the relay which in turn opens and closes the contacts for the light. Here is a diagram.




Now if you still don't understand how a relay works here is a great site that probably explains it alot better than me. http://www.bcae1.com/relays.htm. I have had great succes with this rig. Works very well and stays very consistant. I could probably go and buy a wafer disk and make life alot easier. What fun would that be? Also with the face off the thermostat there is a analog dial reading counter clock wise in larger increments to slow down the rate of cycle for the coil. Turn the needle clockwise to the highest setting allowing for a quicker responce from the thermostat. Good luck.

 

[rebelcowboysnb]

Yes you can use a home thermostat. I have used 2.

My big Incubator that you can see here has one.

It is cycling a 1800 watt hair dryer. It is going on its second year of contenious operation without me having to touch the thermostat. You can watch live video of the thermometer here.

My first incubator was 12Volt an used a home thermostat with no relay.

They work great but if you need someone to tell you how to wire it all up it is probably not your best option.

No, hot water thermostats are not the best thing for the job but nothing will compete with it for under $10. You just have to understand that the more sensitive the thermostat is the farther it has to be from the light bulb but the less sensitive it is the closer it has to be to the light bulb. Hot water thermostats need to be about an inch from the light. Closer in small bator an farther away in a biger one. If you can fit your closed fist between the light an the thermostat its to far away.

 

[Engteacher]

Wow! That distance from the bulb is just the opposite of what I was thinking. I thought it would have to be further away. I can certainly move it nearer.

I'm sure I can pick up a wall thermostat, but it would be hard to find one that would have a range of above 100 degrees. Or, is there a way to trick a normal one out? Most only go up to 90, right?

 

[rebelcowboysnb]

The new cheep wall thermostats(coil type) have an adjustment screw that you can use to make them go that high..

The old murcury bubble types just need to be mounted out of level...
http://cmfarm.us/fridgebator.html
See this one just behind the hair dryer..

 

[debbie.h]

I have my thermosate attached to the hardware cloth that is in front of the lightbulb. That way the back side is close to the heat.

 

[Engteacher]

So after some minor tweaking, here's what I've got. My light bulb stays on until the temperature reaches 101 F. The temp drops to 97.4 and it kicks back on . The cycle time is about 7 minutes. I have a water vial with a thermometer probe inside and that reads 99 to 100.

My humidity is 50%.

So, does it sound like I can chance it with some hatching eggs?

Corrected the cycle time.

 

[rebelcowboysnb]

Sounds good.