I took a look at the controller in your link http://cgi.ebay.com/ws/eBayISAPI.dll?Vi
K:MEWAX:IT. Now from what little info they had posted, my observation is that the heating element just plugs into the controller. Looks like a regular lamp cord type plugin. If that is the case, you can reduce the wattage below the 600w range by simply using nichrome wire and adapting it to attach to a regular lamp cord and plug it into the controller instead of the 600watt heating element that is provided with the unit. Using nichrome wire and measureing its length with an ohm meter to around 60ohms will allow you to reduce the wattage to about 250w. This will result in a lot slower initial warm up time in your incubator, but will also reduce the chance of overshooting the desired temperature range during the on/off cycles of the heating element.
I didnt see anything resembleing a sensor to control the thermostat function. It could be built into the provided heating element, (not likely), might be a seperate external sensor that could be placed somewhere inside the cabinet, or it could be mounted onboard the controller itself. If it is mounted on the controller itself, you would have to place the controller inside the cabinet in order to regulate the temperature. If the sensor is mounted remotely by use of a wire, you can mount the controller outside the cabinet and use the wire to place the sensor inside the cabinet where-ever you want it.
When assembleing your cabinet, I suggest that you do away with your low voltage 12v fans and look for some 120v fans. The fans need to run continuosly, the 120v fans are very simple to wire into your on/off switch and reduce the clutter of haveing to add a lowvoltage adapter in your wireing circuit. You can find 120v pancake fans similar in size and shape as the computer fans you purchased at surpluscenter.com. They are very cheap, $10 +/- depending on the fan you choose
Reguardless of which fan and heating element you choose, you should have the fan mounted to blow air across the heating element and not pulling the heat from the heating element. Pulling the heat from the element will cause excessive heat buildup in your fans and probable shortening the life span of your fan.
Blowing the hot air across your water pan will help create the humidity levels you will need for incubation. I use a large Sterlite container with lids in my incubators. I cut holes in the lids to effect the amount of air flow that actually reaches the water in the container. Start with a small hole and work your way up until you get the humidity ranges you desire. Then cut the hole a little larger and use duct tape to down size the hole. This will allow you to simply pull the tape off to raise your humidity levels during lockdown. If the fan is blowing directly across the water container, and it is full of water, a 2inx2in hole will be a good starting point for finding the right humidity level. I probably should also mention that I use a float valve inside my water container and a seperate water pail connected by a hose to maintain the water level for proper humidity control. If you dont have a float valve you might have to leave the lid off your water tray so that the humidity doesnt fluctuate as much as the water is used up.
The false back inside your cabinet is a good ideal. Most cabinet bators use this method. Usually the heating element is mounted in the top of the cabinet above the egg trays, but seperated buy a false top. the flase top will have some sort of vent slot that allows the warm air to ciruculate downward to the eggs. This is important because it keeps the eggs from coming into direct contact with the very hot air as it is delivered from the heating element. The flase top also provides a place to place your water tray. The fan is usually mounted behind the heating element and on the back side of the false back. The fan blows air across the heating element and draws the reurn air backup from the bottom of the egg tray compartment. This is because a slot is usually cut into the bottom of the false back wall just for this purpose. This circulation means fresh hot air comes down from the top, over the eggs, thru the bottom and reurns to the fan up the back wall of the incubator. Insulating the back exterior wall of the incubator will help reduce heat loss as the warm air moves up the back (much cooler) exterior wall.
If you decide to use the 12v fans and a wall wart to power the fans, you wont have to worry about which wire goes where from the adapter to the fan. If it is connected wrong, the fan will do one of two things, run backwards or not run at all. If this happens, just reverse the wires. How many of the fans you use will just have to be trial and error on your part. The goal is to provide even heat distribution inside the cabinet, not to create a breeze blowing across the eggs. To much airflow across the eggs will result in moisture evaporation from inside the eggs, even though you might have a high humidity reading inside the cabinet.
I didnt see anything resembleing a sensor to control the thermostat function. It could be built into the provided heating element, (not likely), might be a seperate external sensor that could be placed somewhere inside the cabinet, or it could be mounted onboard the controller itself. If it is mounted on the controller itself, you would have to place the controller inside the cabinet in order to regulate the temperature. If the sensor is mounted remotely by use of a wire, you can mount the controller outside the cabinet and use the wire to place the sensor inside the cabinet where-ever you want it.
When assembleing your cabinet, I suggest that you do away with your low voltage 12v fans and look for some 120v fans. The fans need to run continuosly, the 120v fans are very simple to wire into your on/off switch and reduce the clutter of haveing to add a lowvoltage adapter in your wireing circuit. You can find 120v pancake fans similar in size and shape as the computer fans you purchased at surpluscenter.com. They are very cheap, $10 +/- depending on the fan you choose
Reguardless of which fan and heating element you choose, you should have the fan mounted to blow air across the heating element and not pulling the heat from the heating element. Pulling the heat from the element will cause excessive heat buildup in your fans and probable shortening the life span of your fan.
Blowing the hot air across your water pan will help create the humidity levels you will need for incubation. I use a large Sterlite container with lids in my incubators. I cut holes in the lids to effect the amount of air flow that actually reaches the water in the container. Start with a small hole and work your way up until you get the humidity ranges you desire. Then cut the hole a little larger and use duct tape to down size the hole. This will allow you to simply pull the tape off to raise your humidity levels during lockdown. If the fan is blowing directly across the water container, and it is full of water, a 2inx2in hole will be a good starting point for finding the right humidity level. I probably should also mention that I use a float valve inside my water container and a seperate water pail connected by a hose to maintain the water level for proper humidity control. If you dont have a float valve you might have to leave the lid off your water tray so that the humidity doesnt fluctuate as much as the water is used up.
The false back inside your cabinet is a good ideal. Most cabinet bators use this method. Usually the heating element is mounted in the top of the cabinet above the egg trays, but seperated buy a false top. the flase top will have some sort of vent slot that allows the warm air to ciruculate downward to the eggs. This is important because it keeps the eggs from coming into direct contact with the very hot air as it is delivered from the heating element. The flase top also provides a place to place your water tray. The fan is usually mounted behind the heating element and on the back side of the false back. The fan blows air across the heating element and draws the reurn air backup from the bottom of the egg tray compartment. This is because a slot is usually cut into the bottom of the false back wall just for this purpose. This circulation means fresh hot air comes down from the top, over the eggs, thru the bottom and reurns to the fan up the back wall of the incubator. Insulating the back exterior wall of the incubator will help reduce heat loss as the warm air moves up the back (much cooler) exterior wall.
If you decide to use the 12v fans and a wall wart to power the fans, you wont have to worry about which wire goes where from the adapter to the fan. If it is connected wrong, the fan will do one of two things, run backwards or not run at all. If this happens, just reverse the wires. How many of the fans you use will just have to be trial and error on your part. The goal is to provide even heat distribution inside the cabinet, not to create a breeze blowing across the eggs. To much airflow across the eggs will result in moisture evaporation from inside the eggs, even though you might have a high humidity reading inside the cabinet.
