# Maintaining temperature problems



## Cisse (May 2, 2017)

Hello,

I'm having some problems maintaining temperature in the incubator and I hope someone can help me understand the cause.

The incubator is a DIY case, originally used for making yoghurt. It consists of a wooden box with insulation panels on all inside sides (except the door). There is a ceramic heat lamp of 50 Watts mounted in the bottom left corner. There is a simple thermostat relay that will switch the light on when under the preset temperature and off when 1 degree above.

I experimented with various placements of the thermostat sensor, and decided to place it near the lamp at the bottom to have the fastest response time. The problem maintaining temperature seems not directly related to the placement, it just causes the amplitude and frequency of the temperature waves to be a bit different.

The eggs are raised 6 inches or so from the bottom.

I placed an independent wireless sensor on top of the eggs. Please see the chart below:









As you can see, the temperature was maintained without problems until 16:00.

The drastic temperature drop is caused by opening the incubator to turn the eggs. I tried to minimize the time the door was open by quickly taking out the eggs and closing the door, turn the eggs and insert the eggs again.

I let the incubator warm up again, but as you can see, 30 minutes later the temperature curve is stabilizing around 36.4 degrees (Celcius). My first question here is, why does this happen? The thermostat is still set to the same value but this does not result in the same temperature at the eggs location again.

I then turned up the thermostat target temperature considerably and watch the temperature raise to 38.9 degrees again, which is the same top temperature we had before the temperature drop. I then changed the target temperature to the previous value again, thinking that it would be able to maintain the temperature as before, only to see it drop again to a low point at 17:10. I then again turned up the target temperature to see it raise to 38.5 again. I will probably need to continue monitor the temperature evolution and keep on changing the thermostat target until it is stabilized again. However, this whole process takes more than an hour with sub-optimal temperatures for the eggs.

So my second question is, what could I possibly do about this? A stronger lamp? Installing a fan?

Thank you in advance for any insights.


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## seminole wind (Aug 22, 2015)

Some incubators take a long time to recover. What I've heard to do in those cases is to provide some sort of item that will help stabilize the temp. Like balloons filled with water. Or like a hot water bottle (either warmed to the right temp beforehand.) And if possible a heat lamp at the door when you turn the eggs. Otherwise, sometimes thermostats are the problem.


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## Cisse (May 2, 2017)

Thank you, I will add some water containers. So I assume the lamp is not powerfull enough?


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## seminole wind (Aug 22, 2015)

It could be. It depends on how big the area is. If big, you could try adding blocks of Styrofoam to fill up the space. If you use containers for water, put the lids on and use warm water.


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## Cisse (May 2, 2017)

Thanks again for your help. Unfortunately adding water containers did not help much, we still need to keep on adjusting manually after opening the box.

After reading http://www.electronicsprotectionmag...out-temperature-control-and-sensor-selection/ the reason is now much clearer. I guess I should add a fan (to propagate heat faster) and move the thermostat sensor close to the eggs (to react faster).


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## IncubatorWarehouse (Nov 28, 2016)

If you do not mind me butting it, it does sounds like you may have figured out this issue but I have a suggestion. Adding a fan will help keep the air circulating and provide a more reasonable reading to your thermostat and in addition to that we find it best to put your sensor in a centralized location in the incubator to get the most "average" internal reading. Best of luck.


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## Cisse (May 2, 2017)

Not at all, I appreciate the input. The article mentions to put the sensor as close to the target as possible, so I intended to place it at the center of the eggs. I haven't tested any further though since none of the eggs seemed to be fertalized .


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## seminole wind (Aug 22, 2015)

What I did with real babies in incubators is to have a heat lamp on above what I'm doing so opening the incubator is in very warm air.


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