Building a hatcher

[HatchCraft]

I wonder if there is a way to improve the airflow with them mounted to the top? A single layer hatcher would’ve been the easiest to build but if I’m going to have hot and cold spots that won’t matter.

I never achieved a uniformed air flow with a top mount heater/fan over a single layer of eggs . You may have better luck than I did. I hate to think of the time and money spent trying different designs only to discard them. I found directing the air front to back thourgh the egg trays gave me the best temp distribution. Keep in mind air flow also cools the eggs later in the incubation period. Developed embryos are exothermic and egg shell temp exceeds the incubators set temperature. I had real problems with my early hatchers as I insulated the cabinets and experienced runaway temps with energetic breeds. Cornish cross broiler chicken eggs were the worst. It causes you to vent more to off set temp increase that lowers the humidity. If I was in a cooler climate or had climate controlled room it many not have been a problem.

 

[HatchCraft]

I had a sportsman back in the day when they were the wood versions. I later made a couple cabinet incubators with the basic same set up. They all worked well.
With the pepsi-bator I needed to work within the box. I always went with a sportsman like set up cause it was proven but began to wonder if it would work better with the heat source at the bottom since heat raises. It was an incubator only so not any worry about hatching gunk dropping down onto anything.
With that I rethought, overthought then rethought everything again. I don't know any specifics of what works best. Of what is needed exactly. I did and do the trail and error game.
For my incubator I turned everything upside down and inside out. The heat source and thermostat is on the bottom. So is the water pan. I had the fan I put up top and it blows upwards so it's pulling air in and blowing it up then down inside the false wall. I put the second fan at the bottom just so it would blow across the heat source and with the size I thought maybe two fans in two locations would work better.
Everything work better then I even expected with a slightly lower temp at the top. The small bulb at the top evened it all out.
From this build and my past builds I've discovered one thing. It's not rocket science. I think very different set ups can work just as well as others.
You have your basics. Heat, air flow and ventilation. I think you just need to get a box size and configuration and go from there. The bigger the more challenges.
I think the two fans at the top would work potentially. Have an idea on size of the whole thing? Still planning on using your hatching tray or trays? Figure out that then go from there.

In my experience, significant temperature layering top to botton is a sure sign of insufficient air flow. The air flow needs to be really positive in a cabinet style set up. The number of fans, size, speed and volume are really important to achieve a uniform temp. That being said, sportsman incubators are known to vary several degrees top to bottom and people generally have good success. I have used false backs in some incubators but found it's not needed In a multi tray cabinet style incubators if air flow is sufficent for the cabinet size. I have used a false bottom on some single egg layer incubators to return air under the tray.

 

[HatchCraft]

I'm interested in what you've already come up with.
Are you talking multiple stacked trays as a hatcher?
Always stayed away from that idea just because didn't want trays of hatching eggs hatching above others. Common is wire mesh bottoms on the trays. That lends to too much dropping on below trays.
With any solid bottom trays I am wary of getting good air flow throughout.

I use either a solid bottom tray or a liner over wire bottoms. I use the liner in the solid wood trays as well because its easier to clean after the hatch. I would forget trying to flow air through the trays top to bottom. I had terrible results with that design, but other people say it works. Air flowing down the front and through the trays front to back works best for me. Air returns up behind the trays, but no false back required. The area in front and behind the tray act as an air plenum and need to be size correctly for required air flow.

 

[Kung_pao]

Your incubators are awesome looking. I really don’t know much about positive and negative airflows. Or where to put vents and fans. Do you think it might be possible for me to angle the fans for better air circulation vs mounting flush against the top of the incubator.

 

[HatchCraft]

Most table top incubator have the fan centered in the top blowing up with outlet vent holes directly above the fan. The inlet vent will be near the bottom. In theory air blows up and out, down the sides , across the eggs and returns to the center of the incubator. I don't think the air distribution will be perfect, but good enough. Box size, shape and fan of course will have an affect. You'll have to consider where to put a water pan if you don't use the external humidifier. Can you control the fan speed with an incukit?

 

[Kung_pao]

I don’t think the fans are adjustable. I did buy an external humidifier.

 

[Kung_pao]

I never achieved a uniformed air flow with a top mount heater/fan over a single layer of eggs . You may have better luck than I did. I hate to think of the time and money spent trying different designs only to discard them. I found directing the air front to back thourgh the egg trays gave me the best temp distribution. Keep in mind air flow also cools the eggs later in the incubation period. Developed embryos are exothermic and egg shell temp exceeds the incubators set temperature. I had real problems with my early hatchers as I insulated the cabinets and experienced runaway temps with energetic breeds. Cornish cross broiler chicken eggs were the worst. It causes you to vent more to off set temp increase that lowers the humidity. If I was in a cooler climate or had climate controlled room it may not have been a problem.

I had never thought of the developing eggs getting hotter than the incubator without good airflow. It makes sense but had never crossed my mind. It’s really nice to have someone really explain stuff like this.

 

[HatchCraft]

I had never thought of the developing eggs getting hotter than the incubator without good airflow. It makes sense but had never crossed my mind. It’s really nice to have someone really explain stuff like this.

I was looking at the incukit looks like it has a flat plate (heating element) the fan blows againt to distribute the air to the sides. It mentions the fans being high speed which is good for air circulation but might be very loud. The reviews looked positive anyway. Get your box dimensions worked out.

 

[Kung_pao]

Will do, hopefully I don’t work this weekend so I can get this project going.

 

[Kung_pao]

I haven’t abandoned this project. Just became swamped with work and this freezing weather. I’m actually going to talk to someone tomorrow about a coke cooler lol.