Building a diy incubator, need help with the ventilation holes

[alireza18feb]

Hello,
I want to build this incubator (already got the parts) and I need help some help. heres a simple design of whats going to be built, the aspects are 40*35*35

first of all, to get the best results where on the box do I need to drill the vent holes? How many and what size should they be?
and I still dont know where to install the water pot...
can anyone tell my why should the fan blow the air up?how does air circulation work in this design? i thought that because hot air goes up the fan should blow it down but ive seen in so many incubators that the fan blows the air up..

 

[alireza18feb]

Anyone?

 

[nao57]

Well in terms of physics, you are trying to create an effect like a convection oven. That's how convection ovens ended up getting started. They were originally just trying to create stable temperature flow throughout and probably didn't realize they'd be going for a while concept of something that would be like we use today.

The idea is to create and circulate the air flow. Igloos use the same idea to keep warm.

So the concept is to have the air flow intake be near the heat source and the exit of the airflow to be at the other side wherever the least heat is, in order to draw that heat towards the weaker side. So you'd point the fan to be going from where the stronger heat side is towards the weaker heat side to balance the two sides out. But this means you'd have to be using your thermometer a lot over time to take readings and sort of figure that part out first; where the stronger heat is and the weaker heat in the box.

To do this, what people also do is have the intake holes lower, and the exit holes higher; because heat rises up.

But for me the hard part is thinking about how to regulate the temperature. Because overtime the heat source going for several hours doesn't stop. And it doesn't have its own thermostat. (At least I'm pretty sure a lot of them might not have a good thermostat, in the sense of how our houses have them.)

You get it? So a simple design has to be done to be affordable. But without a thermostat there's nothing to tell the machine, OK, how do I know when to reduce my own heat?

This is the part I'm worried about now; regulating the heat over time.

It seems like the reading now of the heat won't be the same 2 hours from now, and 6 hours from now with it on all the time. And that's why I get stressed out thinking about it, because I want it to work.

What I'd discovered is that internally a duck's body temperature is actually really high as an average. When you google this it says its 107.5. But the egg nest would be much, much lower. They use the material to regulate the heat. But the eggs themselves would cook wouldn't they if at 107.5 all the time? So there must be more to it than we realize. If the ducks themselves aren't cooking their own eggs and are somehow getting it to work, then humans should be able to figure out how to regulate it also. (If you are doing chickens, well...they must be built slightly differently.) I'm not saying the temperature should be this high. People will say it should be around 99 degrees. Hope I didn't make people freak out. I was just pointing out the natural brood mother's own body temperature is higher than people realize initially before that heat goes in the nest.

Its just maintaining the consistency over time, I guess.

To be fair I'm not an expert and just a beginner, but I was thinking about these questions myself and these are my thoughts, in the hope it will help you to work it out.

 

[Old McRonald]

For me in a nutshell the fan blows on the heat source whether it's a heating element or a light bulb to help disperse the heat and avoid hotspots in the incubator. As for ventilation holes on my diy cabinet incubator I built last year I drilled 2 holes 1/2 inch in diameter, the first an inch or so from the bottom and the other an inch or so from the top on the opposite side as the other to provide better cross ventilation. I didn't use any method to come up with size, just guessed and it worked great. It wasn't constantly running to keep up to the air exchange and I had a great hatch, only 2 didn't hatch out of close to 40 eggs. The 2 that I lost still pipped but the 1 I should have helped sooner and the other I should have waited longer. What works for me may not work for you, I have had plenty of bad hatches before with cheap purchased incubators which is what prompted me to build one. I am currently builing a new 2 story one, the top will be for chickens and the bottom for call ducks.

 

[alireza18feb]

Well in terms of physics, you are trying to create an effect like a convection oven. That's how convection ovens ended up getting started. They were originally just trying to create stable temperature flow throughout and probably didn't realize they'd be going for a while concept of something that would be like we use today.

The idea is to create and circulate the air flow. Igloos use the same idea to keep warm.

So the concept is to have the air flow intake be near the heat source and the exit of the airflow to be at the other side wherever the least heat is, in order to draw that heat towards the weaker side. So you'd point the fan to be going from where the stronger heat side is towards the weaker heat side to balance the two sides out. But this means you'd have to be using your thermometer a lot over time to take readings and sort of figure that part out first; where the stronger heat is and the weaker heat in the box.

To do this, what people also do is have the intake holes lower, and the exit holes higher; because heat rises up.

But for me the hard part is thinking about how to regulate the temperature. Because overtime the heat source going for several hours doesn't stop. And it doesn't have its own thermostat. (At least I'm pretty sure a lot of them might not have a good thermostat, in the sense of how our houses have them.)

You get it? So a simple design has to be done to be affordable. But without a thermostat there's nothing to tell the machine, OK, how do I know when to reduce my own heat?

This is the part I'm worried about now; regulating the heat over time.

It seems like the reading now of the heat won't be the same 2 hours from now, and 6 hours from now with it on all the time. And that's why I get stressed out thinking about it, because I want it to work.

What I'd discovered is that internally a duck's body temperature is actually really high as an average. When you google this it says its 107.5. But the egg nest would be much, much lower. They use the material to regulate the heat. But the eggs themselves would cook wouldn't they if at 107.5 all the time? So there must be more to it than we realize. If the ducks themselves aren't cooking their own eggs and are somehow getting it to work, then humans should be able to figure out how to regulate it also. (If you are doing chickens, well...they must be built slightly differently.) I'm not saying the temperature should be this high. People will say it should be around 99 degrees. Hope I didn't make people freak out. I was just pointing out the natural brood mother's own body temperature is higher than people realize initially before that heat goes in the nest.

Its just maintaining the consistency over time, I guess.

To be fair I'm not an expert and just a beginner, but I was thinking about these questions myself and these are my thoughts, in the hope it will help you to work it out.

Thank you Nao, the info was really well written and through, however I still haven't got my answers, of course I'm using a digital thermostat, I don't know where to put the sensor, and I still don't know where I should drill the vent holes, and what size they should be

 

[alireza18feb]

Thank you

For me in a nutshell the fan blows on the heat source whether it's a heating element or a light bulb to help disperse the heat and avoid hotspots in the incubator. As for ventilation holes on my diy cabinet incubator I built last year I drilled 2 holes 1/2 inch in diameter, the first an inch or so from the bottom and the other an inch or so from the top on the opposite side as the other to provide better cross ventilation. I didn't use any method to come up with size, just guessed and it worked great. It wasn't constantly running to keep up to the air exchange and I had a great hatch, only 2 didn't hatch out of close to 40 eggs. The 2 that I lost still pipped but the 1 I should have helped sooner and the other I should have waited longer. What works for me may not work for you, I have had plenty of bad hatches before with cheap purchased incubators which is what prompted me to build one. I am currently builing a new 2 story one, the top will be for chickens and the bottom for call ducks.

Thank you Mr. McRonald, so I will drill two holes on each sides one at the top and the other one at the bottom right? And where should I place the water pot and the thermostat and hydrometer sensor? And becuase I live in a port city my room humidity is about 50 percent, should I avoid the water pot before the hatch period? Sorry for asking too many questions, I just thought I'd use your precious experience

 

[nao57]

A lot of people seem to be trying to put the thermometer, thermostat etc as close to the center of 'where the eggs will be' as they can in the videos I'm seeing. And that makes the most sense to me. And technically you don't have to only have one thermometer. I got two of them, so I could play around with the readings a bit and spaced them around the middle. (But that can also increase stress at first, because it makes you very aware of how hard regulating temperature is like the others said.) It was quite alarming to me how the center of my box near the heat would be just right, but the far corner of the box would have a drastically different temperature before I started using towels.

I'm afraid I don't have enough experience to tell you how many holes and how big they should be. But I still do think you want the intake low probably low and under the heat source (think how igloos work), and the outvent high up where you are trying to draw the heat from.

*Some of how big the holes should be will also depend on how powerful your heat source is.* To determine that you'll probably have to leave the heat on for awhile and play with temperature readings for a bit 'over time' to find out if you are too hot or too cold.

So you have an advantage also.

If you look at natural humidity outside by average for your state, you will see you have a natural humidity advantage in March and winter months for bonuses to humidity. Cool right? XD (Although by the same token it may be harder in the deep summer heat for some states and areas.) In theory, the humidity sensor could be somewhat affected by the elevation of height off the ground the machine, and also elevation inside of how high or low you place it. But I don't know specifically how much those readings will change off a few inches.

This stuff is pretty interesting to think about.

Now about whether you should wait on putting in the humidity sensor...that's tricky because you are also weighing out if its too humid with also, if you skip having experience using the humidity this time, you'll have less experience on it next time. Plus, if you practice using the humidity sensor now, that will let you work out any needed tweaks and fixes now. But the humidity will be harder for you to work with later in the summer and early fall if your state is like mine. Here in Utah, we have higher humidity in winter months and really dry semi-desert summers and early falls. (But for some people that might be the different if you are by the coasts or deep south.)

 

[LLranch]

I have built several incubators over the years and find the temperature stays most stable with the heat directly on the intake side of the fan and the thermostat probe connected directly to the output side of the fan this makes is cycle on and off more and quicker for less temperature swing. The vent holes are an after thought when I'm testing the incubator make more or bigger holes to lower the humidity less or smaller holes for higher humidity

 

[alireza18feb]

A lot of people seem to be trying to put the thermometer, thermostat etc as close to the center of 'where the eggs will be' as they can in the videos I'm seeing. And that makes the most sense to me. And technically you don't have to only have one thermometer. I got two of them, so I could play around with the readings a bit and spaced them around the middle. (But that can also increase stress at first, because it makes you very aware of how hard regulating temperature is like the others said.) It was quite alarming to me how the center of my box near the heat would be just right, but the far corner of the box would have a drastically different temperature before I started using towels.

I'm afraid I don't have enough experience to tell you how many holes and how big they should be. But I still do think you want the intake low probably low and under the heat source (think how igloos work), and the outvent high up where you are trying to draw the heat from.

*Some of how big the holes should be will also depend on how powerful your heat source is.* To determine that you'll probably have to leave the heat on for awhile and play with temperature readings for a bit 'over time' to find out if you are too hot or too cold.

So you have an advantage also.

If you look at natural humidity outside by average for your state, you will see you have a natural humidity advantage in March and winter months for bonuses to humidity. Cool right? XD (Although by the same token it may be harder in the deep summer heat for some states and areas.) In theory, the humidity sensor could be somewhat affected by the elevation of height off the ground the machine, and also elevation inside of how high or low you place it. But I don't know specifically how much those readings will change off a few inches.

This stuff is pretty interesting to think about.

Now about whether you should wait on putting in the humidity sensor...that's tricky because you are also weighing out if its too humid with also, if you skip having experience using the humidity this time, you'll have less experience on it next time. Plus, if you practice using the humidity sensor now, that will let you work out any needed tweaks and fixes now. But the humidity will be harder for you to work with later in the summer and early fall if your state is like mine. Here in Utah, we have higher humidity in winter months and really dry semi-desert summers and early falls. (But for some people that might be the different if you are by the coasts or deep south.)

OK I'm gonna avoid using elements as I've been told that they can cause fir or that they keep releasing extra heat after their power is cut but the thermostat, so what I'm gonna do is I'm gonna use two 100 watts light bulbs as they are convenient and easy to find, so can you please have another look on my design, the fan blows the air up into the light bulbs, then how does the air circulate? And according to this, where on the box should I put the holes? I'm attaching a picture of this incubator I've recently seen and I'm very pleased with how it looks, I've seen it's efficiency as well, so I thought I'd built one myself, I want to know where the vent holes and the sensors are placed in this incubator and I seemingly can't guess.

So that's an advantage? If the humidity inside the incubator is 45 percent already I'm not gonna be using water inside it?
Oh I don't live in America sir, I live in a hot and humid city, a port city in Iran.

Thank you so much for the info, I'm still confused with the vent holes, I'd be really grateful of you could mark them on my design photo.

Please take a look at this design, I can't seem to locate the vent holes and the sensors in this incubators, can you?

 

[LLranch]

Thank you sir, so when you consider adjusting the correct humidity needed, do you also consider ventilation since eggs also need to get enough oxygen and that only results from a proper air ventilation?

I have never had embryos die due to a lack of oxygen they simply don't need that much. Also light bulbs continue to put off heat for several seconds after they shut off just like a heating element I have used both over the years I have lost hatches due to light bulbs burning out heating element seemed to last a long time without burning out