Homemade cabinet buld ?'s, false back and fan question?

[KYBOY]

Im looking at building a cabinet hatcher/incubator with shelves sized so I can use my 42/egg turners in it for incubation if I want..Ive pretty much decided to go with a standard coil heat source with a back up wafer and a PID control/RTD PT100 sensor for the temp control. Im kicking around the idea of a false back for circulation. do you think its worth the trouble? Also the standard GQF fan(210CFM) is around $48..Does anyone know a good alternate source for a metail fan of that size?
thanks

 

[HatchCraft]

I have built with and without false backs. I don't use false backs anymore. Assuming you are building an incubator patterned after the sportsman type incubator and as long as there is plenty of air flow you won't need one. Use a high cfm fan like you were describing and allow for a 3" or more space top to bottom in front of and behind the turners . Don't make the incubator any taller than necessary . Using a false back will even out the temps top to bottom, but won't allow for the front to back laminar air flow over each tray of eggs. And as a side note, base on my experience, builders way over ventilate incubators.

 

[KYBOY]

yep, not really trying to reinvent the wheel on this one..I already have a Dickey cabinet bator and Im gonna make this mostly a hatcher but able to use my small turners if I want..Gonna use the size fan that comes in the dickey, the heating element but Im going with PID controls for temp..

 

[HatchCraft]

No need to reinvent the wheel , it is a solid design of which I have built a hundred.I use a lot of PID controllers , occasionally with the wafer backup. Quality PIDs are very reliable, but like everything electronic they can fail. I install the backups with a double pole single throw switch in case there is a failure to heat. Like if the ssr fails or there is an open sensor. This will let you chose between the normal position of PID controller with high temp wafer backup or if it fails to heat, the switch lets you bypass the controller altogether and run solely on the wafer thermostat. Also useful being able to bypass the controller when setting backups temp.

 

[KYBOY]

That's a good idea, I was already planning on the wafer backup. Im going to order a PID from auberins. They have the SSR's and RTD probes too. I guess you break the lines between the PID and wafer with the switch????

 

[HatchCraft]

If your using a pid you want one that will drive an ssr as opposed to a mechanical relay. They make both types. In one position the dual pole switch send power to the line voltage side of the relay . The controller will open and close the connection between the line and load side of the relay. With the switch in the bypass position power is sent directly to the load side of the relay. The wafer thermostat is wired between the load side of the relay and the heating element. Sorry, a drawing would be better . Hope you can understand my explanation.

 

[KYBOY]

Yea I understand the pid I'm ordering will drive an ssr relay. Basically the pid(and ssr) replace the front wafer of a duel wafer set up and the switch breaks power from the pid to the back up wafer? Correct me if I'm wrong it's been a long day. LoL