Homemade incubator - alternate method to regulate temp

[BrownEggFan]

Hello, I am new to this site and the world of backyard chickens! I recently built a chicken tractor and received 3 Rhode Island Red hens from a friend who wanted to reduce the size of his flock. These chickens had been with a RIR rooster, so I'm hoping that I may be able to incubate some eggs. I read several of the pages on making homemade incubators and made one minor change to the heat control. All of the designs utilized a water heater thermostat to regulate the temperature when using a lightbulb for a heat source. Because I like to experiment, and because I had it already, I used a regular dimmer switch so that I could adjust the wattage of the bulb. After completing the incubator, I turned on the switch and let it go for a few hours. I had to adjust the dimmer a few times, but finally got it stabilized at 100 deg. I only have an analog thermometer right now, but I'm going to purchase a digital one with a hygrometer before I add any eggs.

 

[ga_goat]

That was the way I done my first one , be careful about opening it after it has / had stabalized it sometimes don't go back to where it was .and drafts are critical with the dimmer setup .

 

[aprophet]

Quote:
If the air surrounding your bator stays exactly the same temp 24/7 then you are OK if the temp changes outside your bator then the temp inside will do the same if you are there to correct it cool, if not thats what a t-stat does

 

[muddstopper]

Heres just my take on using a dimmer switch.

First, the switch works by provideing resistance to the elctrical current. This excess current is then given off as heat. What this could mean is that over time your dimmer switch could actually burnout and possibly catch fire. Granted, the dimmer switch could last a very long time before this happens, but then again, it might burnout in the first week.

Second, a dimmer switch is made to regulate electrical current and not temperatures. what this will mean is that as the temps outside your incubator fluctulate, the dimmerswitch is not going to sense this change or provide for any corrections in the amount of electricity needed to maintain your desired temp. In other words, you most likely will have to continue to fiddel with it to keep your temps where you want them.

The only way a thermostat controls the electricity is by turning it on or off. It does this by using metal contacts that expand and contract according to the changes in the ambient temperature. Metal expands as it heats up, this expansion is usually used to break the contacts that carry the electrical current. As the metal cools off, it contracts which will close the contacts and send the electricity on down the line.

Even the more modern electronic thermostats will use the old expansion and contraction method for sensing temperatures. They might also be equiped with other electronic circuitry that can sense when the temp is approaching the desired setting and instead of just truning the elec. on or off, instead reduce the current to the heat source. This is to help insure that you do not get a overshoot or undershoot in your temperature control. Some thermostats also use a pulsewidth modulation that actually sends the electricty to the heat source as little pulses of power, these circuits are never really on or off, but will turn off if the correct temp setting is overshot, which doesnt happen very often with this type of thermostat. Since the power is supplied in small bursts a little at a time, these thermostats will hold very stable temperatures.

 

[BrownEggFan]

Thanks for the input, everyone. This definitely gives me some things to think about. I plan on keeping the incubator in my basement so the outside temperature should remain pretty consistent since it is below grade. Also, there shouldn't be any drafts as there are no windows or doors. However, I realize that a few hours of consistent temps is different than 21 days and I don't want to experience any drastic temperature fluctuations 2 weeks into the process. Maybe I'll go get a thermostat...

 

[BrownEggFan]

I purchased a digital thermometer and hygrometer and put it in the bator for about 2 weeks. I also added two small jelly jars full of water for mass. At the end of two weeks, the high temp was 107.4 and the low was 91.8.

I've purchased a thermostat and will be installing it before any eggs get added!