Designing a new incubator... Any input and advice will be greatly appreciated!

[Aphrael]

Above is a sketch of how I understood Jessshan8's suggestions... Did I understand correctly? The bulbs would be behind the divider, and the fan placed in the divider. Vent holes in the back cover... However, I want to ask if I should rather put the 3 bottom vent holes in the divider? Since that will be solid... OR make the divider out of wire mesh and wood? The red x is the placement of the thermostat wire... And then several thermometers will be placed inside the machine... Looking okay? I really want to do this right

Tomorrow I will start building the box

You'll need either an intake fan or leave a gap in the divider. You need somewhere for the cooled air to suck in and then get heated to blow out the other end, creating air flow around the box. In my opinion, from my limited experience I would have more than one fan blowing the heated air out. I know there are some who say you don't want to much air flow. But in my (again very limited) experience with my homemade incubator, more is better. I have 2 fans for a smallish coolerbator (1 blowing across each bulb). If I turn off both fans there are hot and cold spots of course. With only one fan the temps vary by several degrees, but with both fans on it holds rock steady, only altering by 0.3c (which is the minimum variance setting on the stc-1000). Anyway, just my $.02. I'm eager to see how your build comes along.

 

[Aphrael]

I see that no one actually answered your question. I have built several incubators like the one you are designing and have found that if you place the light bulbs 2/3's the way up in the back with a fan just above them it works really well to draw the heat from the lights and force it in somewhat a circular motion. Up across the lights over and across the eggs to be drawn up again past the light bulbs. I would use no more than 2 75 watt bulbs though and would, if it were mine 2 65 watt bulbs. Placement of the thermostat is crucial as well. I wound place it between the two bulbs and just slightly above them. I would also do a test run on it just to make sure the temps stay within parameters. (99.5 +- 1 deg F) as you might need to move the thermostat to get it placed just right to maintain temp. Good luck and I look forward to seeing the finished results. Hopefully you will post them (pics).

I'm curious as to why you would put the thermostat sensor near the lightbulbs? Should it not go into the egg area so you know that part is heating to the correct temp? It seems to me that right near the lightbulbs it would heat fast and turn off before the main chamber could heat up. I understand the reasons behind putting a water heater thermostat near the lightbulbs. But I'm confused why a digital probe would need to be near them also. Could you please explain? I am trying to learn as much as possible about building these as efficient as possible.

 

[BoereMeisie]

You'll need either an intake fan or leave a gap in the divider. You need somewhere for the cooled air to suck in and then get heated to blow out the other end, creating air flow around the box. In my opinion, from my limited experience I would have more than one fan blowing the heated air out. I know there are some who say you don't want to much air flow. But in my (again very limited) experience with my homemade incubator, more is better. I have 2 fans for a smallish coolerbator (1 blowing across each bulb). If I turn off both fans there are hot and cold spots of course. With only one fan the temps vary by several degrees, but with both fans on it holds rock steady, only altering by 0.3c (which is the minimum variance setting on the stc-1000). Anyway, just my $.02. I'm eager to see how your build comes along.

Thanks for your input... It makes sense to put in two fans... I'm such a newbie at this, having made one cooler box incubator with a very bad hatch rate (1 chick out of 22 eggs) I know I need as much input and advice as possible! Hence all the sketches... lol

I'm curious as to why you would put the thermostat sensor near the lightbulbs? Should it not go into the egg area so you know that part is heating to the correct temp? It seems to me that right near the lightbulbs it would heat fast and turn off before the main chamber could heat up. I understand the reasons behind putting a water heater thermostat near the lightbulbs. But I'm confused why a digital probe would need to be near them also. Could you please explain? I am trying to learn as much as possible about building these as efficient as possible.

Hmmm... Another point to ponder... I'm also thinking placing the sensor near the eggs might be better... I don't know!

 

[dheltzel]

For calibrating thermometers, remember that water does not boil at exactly 212 (or freeze at exactly 32). With distilled water a sea level you can get very close
What I do is to calibrate it with a digital infant thermometer. They must be very accurate in the range that we want (98.6 to 100+ degrees).

Probably either method gets it close enough, but I find the boiling/freezing a lot more work than buying another thermometer.

 

[Jessshan8]

Quote: The placement of the sensor close to the bulbs is to prevent over heating as the bulbs will heat everything up from the bulbs then moving out. You could have the temps as much as three degrees higher closer to the bulbs then where the sensor is depending where the sensor is. This helps prevent over cycling of the bulbs and the fans will help even out overall incubator temperatures.

I would leave three inches open both under and over the divider to facilitate optimum air circulation. You could cover the bottom opening in wire if you desire. As far as the bulbs you can use the double bulb fixture such as in ceiling lights in a house. I have found them at out local thrift store for about 2 to 3 bucks. You might have to take apart the fixture apart to get the bulb fixture but that is super easy as they are just held in place by a metal flat spring type connection or threaded tube, like the photo below minus the pull switch.

 

[Jessshan8]

Quote: Placing the thermometers with the eggs and adjusting where the sensor is will give you the best result. There is no one perfect answer here. The object is to get steady and optimum temps at the eggs. You might have to adjust the placement several times to get the best results. I would recommend running it for thee or four hours to ensure stability where ever you end up with the sensor.

 

[aart]

For calibrating thermometers, remember that water does not boil at exactly 212 (or freeze at exactly 32). With distilled water a sea level you can get very close
What I do is to calibrate it with a digital infant thermometer. They must be very accurate in the range that we want (98.6 to 100+ degrees).

Probably either method gets it close enough, but I find the boiling/freezing a lot more work than buying another thermometer.

So you can check your boiling temp at altitude here. I'd check even a digital infant thermometer against a known.

 

[dheltzel]

I agree that any consumer-grade thermometer could be off. I thermometer intended for human use is likely to have pretty strict manufacturing spec, no one wants to get sued for being off 2 degrees and some kid getting brain damage.

Has anyone tried the infrared thermometers you just point at a surface? I don't know how accurate they are, but it's a intriguing idea to be able to scan the eggs to see if any are hotter or colder. Finding a temperature difference could make possible to adjust air flow to even it out.

Sometimes I just like high-tech for it's own sake. A mother hen is hard to beat and she's doesn't have any of that technology, but I still like it!

 

[Aphrael]

The placement of the sensor close to the bulbs is to prevent over heating as the bulbs will heat everything up from the bulbs then moving out. You could have the temps as much as three degrees higher closer to the bulbs then where the sensor is depending where the sensor is. This helps prevent over cycling of the bulbs and the fans will help even out overall incubator temperatures.

I would leave three inches open both under and over the divider to facilitate optimum air circulation. You could cover the bottom opening in wire if you desire. As far as the bulbs you can use the double bulb fixture such as in ceiling lights in a house. I have found them at out local thrift store for about 2 to 3 bucks. You might have to take apart the fixture apart to get the bulb fixture but that is super easy as they are just held in place by a metal flat spring type connection or threaded tube, like the photo below minus the pull switch.

Placing the thermometers with the eggs and adjusting where the sensor is will give you the best result. There is no one perfect answer here. The object is to get steady and optimum temps at the eggs. You might have to adjust the placement several times to get the best results. I would recommend running it for thee or four hours to ensure stability where ever you end up with the sensor.

Than you very much for the explanation. That makes a lot of sense. I am one of those people who can't stand doing something just because that's "the way it is supposed to be". I go crazy until I find out WHY something is done a certain way. I need things to make sense to me. I'm guessing I didn't run into problems with my little coolerbator because it is fairly small and even sitting with the eggs it wasn't all that far from the bulbs, and it is also all open except for a foil shield to keep the direct light from the eggs. Your suggestion and explanation is probably going to save me a lot of grief when I get my cabinet built. So again thank you!!

So you can check your boiling temp at altitude here. I'd check even a digital infant thermometer against a known.

Ooo. Thanks for that link. Very helpful!

 

[Aphrael]

Thanks for your input... It makes sense to put in two fans... I'm such a newbie at this, having made one cooler box incubator with a very bad hatch rate (1 chick out of 22 eggs) I know I need as much input and advice as possible! Hence all the sketches... lol

Hmmm... Another point to ponder... I'm also thinking placing the sensor near the eggs might be better... I don't know!

I LOVE your sketches, and I'm following your thread with great interest! Your design looks very much like what I'm hoping to build soon to replace my coolerbator. Do you think you'll get it built in time for the hatch-a-long? Set time is getting close!