Use of used equipment for new ones goals - this is not just a tribute to an environmentally friendly lifestyle, but also a real cost savings for the farmer. Old refrigerator has ideal tightness and thermal insulation, which makes it an excellent basis for creating a home incubator. Unlike foam boxes, the metal case holds its shape better and protects the contents from rodents and mechanical damage.
The conversion process requires an understanding of the basics of thermodynamics and electrical engineering, since you have to create a closed system with forced air circulation. The main task is to transform a static cold box into a dynamic environment where temperature and humidity are maintained with an accuracy of tenths of a degree. This is critical for the survival of embryos.
In this article we will analyze in detail each stage of transformation, from dismantling internal equipment to calibrating sensors. You will find out why the power of heating elements for a volume of 300 liters should not exceed 400-500 Wattsto avoid overheating and death of the bookmark. The correct approach will allow you to obtain output comparable to industrial designs.
Preparation of the case and dismantling of equipment
The first stage is complete disassembly of the internal space. You need to remove all shelves, vegetable drawers and, most importantly, dismantle evaporator and the condenser on the back wall. Be extremely careful when disconnecting the pipes if there is freon left in the system - its release into the atmosphere is prohibited, so it is better to contact a specialist to safely pump out the refrigerant.
After releasing the volume, evaluate the condition of the sealing rubber on the door. Tightness is a key parameter on which stability depends microclimate. If the rubber is cracked or has lost its elasticity, it must be replaced or restored with special means, otherwise heat loss will negate the work of the heaters.
⚠️ Attention: When dismantling the back panel and working with metal tools inside the chamber, do not damage the internal contour of the thermal insulation. If you puncture the wall of the refrigerator, the tightness of the insulation will be broken, and the structure will begin to freeze or overheat in the defect areas.
It is better to clean the internal walls of old plastic, if it has a persistent odor, and treat it with an antiseptic. Many craftsmen prefer to line the inside with food-grade aluminum or stainless steel to facilitate disinfection after each hatching cycle.
Heating and ventilation system
Organization of proper heat exchange is the heart of your future incubator. Unlike a freezer, there is no need for cold, so a compressor will not be used. To heat the air, traditionally incandescent lamps or nichrome spirals enclosed in a safe casing are used. Lamps with a power of 40-60 W, connected in parallel, are a simple and reliable solution.
However, simply heating the air is not enough. Without air movement, “heat pockets” form in the chamber, where the embryos in the upper trays will cook and those in the lower trays will freeze. Therefore, installation fan is required. It should work constantly, ensuring uniform distribution of heat throughout the entire volume.
The location of the heating elements should be such that the air flow from the fan first passed through them and then was distributed throughout the chamber. It is optimal to place heating elements in the lower part or on the side, but not directly above the eggs.
- 🔥 The heating element must have a thermostat to turn off when the set temperature is reached.
- 💨 The fan is directed to the heater or along the back wall to create a circulation.
- 🌡️ The temperature sensor is located at the level of trays with eggs, and not at the wall of the housing.
Automation and microclimate control
It is impossible to imagine a modern incubator without electronic controller. Manual temperature control using rheostats is a thing of the past, as it does not provide the required accuracy. For homemade designs, universal thermostats are ideal, such as XH-W3001 or more advanced Rexantthat control turning the heater on and off.
The controller receives data from the sensor and closes the power circuit of the heating elements. It is important to adjust the hysteresis (temperature delta) so that fluctuations do not exceed 0.2–0.3 degrees. Switching on and off too frequently will shorten the life of the relay, and too rarely will lead to temperature fluctuations that are dangerous for the bird.
To control humidity, you can also use automation by connecting an ultrasonic humidifier or a simple water heater through the second relay of the controller. Although many farmers prefer to control humidity manually, adding water to the trays as needed, automating this process greatly simplifies maintenance, especially at night.
Manufacture of trays and turning mechanism
The internal space of the refrigerator allows you to create a multi-tiered structure. Trays are made of metal mesh with a cell of 15x15 mm or of wooden slats covered with mesh. The distance between the tiers should ensure free circulation of air, but at the same time allow the maximum number of eggs to be placed.
The turning mechanism is a critically important unit. In the first two weeks of incubation, eggs must be turned at least 4-6 times a day (and ideally every 2 hours) so that the embryo does not stick to the shell. In the conditions of a homemade incubator from a refrigerator, the easiest way to implement a tilting mechanism.
The essence of the method is simple: the trays are fixed on one common axis or frame, which can tilt in one direction or the other at an angle of 45 degrees. The drive can be a regular one geared motor-wheel from car wipers or an electric motor with a gearbox controlled by a timer.
☑️ Checking the rotation mechanism
An alternative to tilting is to use a roller system where the eggs lie on rotating rollers, but for a refrigerator the inclined frame is structurally simpler and takes up less usable volume.
Calculation of power and energy consumption
The energy efficiency of a home-made device directly depends on the quality of thermal insulation. A standard household refrigerator with a volume of 300-350 liters in winter at a room temperature of +20°C consumes significantly less energy than in summer. However, the heaters must be calculated with a margin.
Usually, to maintain a temperature of +38°C in a well-insulated housing, 10-15 watts for every 10 liters of volume are sufficient. That is, for our refrigerator, the total power of lamps or heating elements should be about 400-500 Watts. Exceeding this power will result in the thermostat operating in the “on-off” mode at very short intervals.
| Parameter | Value for a volume of 300 l | Note |
|---|---|---|
| Power heating | 400-500 W | Optimal 4 lamps of 100 W each |
| Consumption per day | 3-5 kW/h | Depends on external temperature |
| Humidity (1-18 days) | 50-60% | Hygrometer control |
| Humidity (19-21 days) | 70-80% | Biteing period |
It is important to consider that Incandescent lamps not only provide heat, but also light. This can be a benefit for visual control, but some bird species prefer hatching in the dark. In this case, the outer part of the glass can be painted over or IR heaters that do not produce visible light can be used.
Launch, testing and debugging
Before laying expensive hatching eggs, the device must go through the stage idle run. Turn on the incubator without eggs and observe the thermometer readings at different points in the chamber. The temperature spread should not exceed 0.5 degrees. If it is colder in the corners, add an additional fan to mix air masses.
Check the operation of the humidification system. The water should evaporate evenly without forming condensation on the walls, which could drip onto the eggs. Condensation is a sign of poor ventilation or excess humidity, which leads to the development of mold and bacteria.
⚠️ Warning: Do not use flavored water or additives not intended for incubation for hydration. Steam with chemical impurities can penetrate through the pores of the shell and destroy the embryo.
The secret of stable humidity
Place a wide, but not deep container of water in the lower part of the refrigerator. The larger the evaporation area, the more efficient fanless humidification works. To quickly increase the humidity before biting, you can throw a sponge into the water, which will increase the surface area.
After successful testing for 2-3 days, when you are convinced that all parameters are stable, you can start laying. Keep a log, recording the temperature, humidity and time of each egg rotation.
Hygiene and disinfection after hatching
After the chicks hatch and the cycle is completed, fluff, shell remains and specific microflora remain in the chamber. The metal body of the refrigerator allows for aggressive disinfection, which is not available for foam analogues. Use solutions of chloramine or hydrogen peroxide to treat all surfaces.
It is better to wash removable trays with a brush and laundry soap, and then dry them in the sun. Ultraviolet light is excellent at killing remaining bacteria. Regular cleaning of fan filters is also mandatory, as fluff can clog the blades and disrupt air circulation in the next cycle.
Keeping cleanliness is the key to ensuring that your fan will last for many years. Mold that has settled in the cracks of the seal or on the shelves can cause the death of the next generation of birds, so do not be lazy to carry out general cleaning after each hatch. refrigerator incubator will last for many years. Mold that has settled in the cracks of the seal or on the shelves can cause the death of the next generation of birds, so do not be lazy to carry out general cleaning after each hatch.
Is it possible to use an old refrigerator with a non-working compressor?
Yes, this is an ideal option. A compressor and cooling system are not needed in the incubator; they only take up space and can create unnecessary noise. The main thing is that the body is intact and the door closes tightly. If the compressor interferes with the placement of trays, it can be carefully dismantled by cutting the tubes (after making sure that the freon has come out).
What humidity should be in the incubator from the refrigerator?
In the period from 1 to 18 days (for chicken eggs), the humidity should be kept at 50-60%. From the 19th day, when hatching begins, the humidity is increased to 70-80% to soften the inner shell of the shell and help the chick get out. For other types of poultry, the parameters may differ.
Is it necessary to make holes for ventilation in the housing?
Yes, an absolutely sealed refrigerator will “suffocate” the embryos. It is necessary to drill holes with a diameter of 20-30 mm in the lower part (for inflow) and in the upper part (for exhaust). Their total area should be about 10-15 cm² for every 100 liters of volume, but the exact size is selected experimentally so as not to disturb the temperature regime.