Heating system for poultry houses
?What is the reason for using modern heaters to heat the houses
As we all know, in the different stages of broiler farming, the most sensitive stage of farming is from the first day to the age of fourteen days, and at this stage, providing suitable environmental conditions is very important. At this special and sensitive stage of farming, because the chickens are kept in an enclosed part of the house, the heaters inside the house must provide the desired temperature at the standard level for the growth of the birds. For this reason, creating an environment with the right temperature for the growth of the chickens is important and vital for better performance during the breeding period.
What is poikilothermic? This may be the first time we have come across this word, but it is nothing more than this: at the age of 4-7 days, from the beginning of the chicks’ rearing period, they are not able to provide their own internal body heat, and the breeder must help the chicks with the heating system installed in the house to provide heat so that they do not face any problems during the rearing period, and therefore heaters play an important and fundamental role in providing heat to the house. To achieve the set goals, a standard temperature must be provided for the birds, which is a comfortable and pleasant temperature range for the birds. In this regard, whenever the temperature of the house is too low and persistent, it affects the performance of the poultry, as they gather together in this low temperature range and their activity decreases, and subsequently the search and activity for water and feed consumption ceases, and they will not have the desire to consume food and use the energy they have already stored to warm themselves (the internal body temperature of the chicken reaches 23.3 degrees Celsius before death). Conversely, if the temperature of the house reaches about 45 to 47 degrees Celsius (the temperature of dehydration), the chickens are forced to avoid consuming water and feed to cool themselves and they start panting and spreading their wings, and as before, instead of being used for weight gain, energy consumption works in the opposite direction and imposes more costs on the producer.
After 14 days, the next stage of poultry farming is called the production stage, in which the entire house is available to the birds, and in this stage, heaters again play an important role in providing the desired temperature of the house. (In normal and usual conditions, the entire house is not provided to the birds until the 21st day of farming). And after the 21st day, the growth and production periods are almost combined, where the chickens are able to provide their own internal heat and start to gain weight.
The primary goal of raising broiler chickens in the house is to ensure that they grow well and create a comfortable environment for them to gain weight. This is very challenging in places where the air temperature is very cold and we want to hatch them exactly in the cold season. If you have noticed, the temperature of the house is high in the early part of the breeding period depending on the age of the chickens, and the older they get, the lower the temperature is so that we can provide a suitable environment for the birds and show better performance. As mentioned, the younger the chicks are, the more they need an external heating system to provide their internal body heat (appropriate heat must be provided in their environment to maintain their internal body temperature so that they do not have to spend energy to warm themselves) and vice versa, as the birds get older, because their body system produces heat to heat them and we must gradually lower the temperature of the house so that they avoid panting to cool themselves. Keep in mind that the heat supply should be based on the breed and a number of other factors (of course, it also depends on whether the age of the mother flock from which they were hatched is over 30 weeks or less). According to the catalog and poultry farming guide, the temperature of the house at one day old is always considered to be 30 degrees to 33.4 degrees Celsius (of course, breeders sometimes need to raise the temperature of the house to 34 degrees Celsius). (Of course, it is always very useful to follow the guide and sometimes you can reduce or increase the temperature of the room to the appropriate level based on experience) and accordingly, after each day of increasing the age of the birds, reduce the temperature of the room according to the recommended instructions, which is done gradually and until the temperature of the room is reduced to 21 to 18.5 degrees, which is around the age of 30 days. And if the breeder wants the birds to have more weight, and this is usually over 60 days of age, the temperature of 18 degrees and a little less is very suitable for them because their weight has increased and more heat is not suitable for them.
Heating Systems for Poultry Houses
:There are two types of heating systems commonly used in broiler farming
Radiant Heaters
Ceiling-mounted (ground-mounted) heaters
Ceiling heaters, which can be either pedestal-mounted or suspended, heat the air inside the house. However, radiant heaters perform three functions: heating the air inside the house, the birds, and the house bedding. Research that has focused on both types of heating systems has shown that both are effective in improving poultry performance. Although most producers in developed countries currently believe that the second type of heating system cannot provide a suitable solution for optimal poultry performance and growth, they mostly use the first type to heat the house because ceiling heaters cannot heat the floor of the house, the litter, and the poultry as they should. Of course, it should be noted that in the early stages of breeding, using bedding materials such as straw on the floor of the house is a necessity to keep the poultry warm.
?What is radiant energy
Radiant energy flows in the air in the form of electromagnetic waves and collides with objects, and as a result of this collision and contact, it transfers the heat it has stored in itself to the object (such as sunlight and infrared light); of course, it should be noted that the radiant energy emitted from the energy source depends on the ambient temperature (the higher the ambient temperature of the energy source, the more energy it emits). For this purpose, infrared cameras can be used on various surfaces, objects, and objects for greater certainty. Radiant heaters provide desirable heat for birds in two ways. The first method is that since the chicks are in the environment, they directly absorb radiant energy using their physical shape (volume) and absorb heat. The second method is that the litter in the house, since it occupies a large surface area, also absorbs radiant heat and thus absorbs heat from objects. It should be noted that since the litter also receives heat, this same thermal energy is again transferred to the chicks through the legs and a desired desired thermal environment is created and maintained between the chicks and the litter. In the meantime, the temperature of the litter under the radiant heater can increase up to 54.4 degrees Celsius (keep in mind that most small birds transmit cold to their internal body space through their legs, and whenever we can choose a method for heating the litter that is more reliable, it will be more economically suitable for the breeder). And of course, the further away we are from the heating environment, the less heat it will provide (when someone visits the breeding hall, they may feel a temperature difference of 5 to 10 degrees above the heads of the chickens, but since there is no fixed object in that space to receive the energy, this is why the difference in temperature between the chickens and the height is felt higher).
Heater Source Gas Pressure
The energy source of radiant heaters is natural gas or propane and varies depending on its type (the style of the heater and its type). And based on the pressure of the gas supply source required, they are divided into two general categories. In normal conditions, heaters that operate with a small amount of gas (natural gas) usually operate with a pressure of 5 to 14 inches of water column, and for heaters whose energy source is propane gas, the gas pressure is around 11-14 inches of water column (Note: An inch of water column is a unit of pressure measurement that is mainly used in North America to measure small differences in pressure, meaning that 1 inch of water is the pressure exerted on it by a column of water 1 inch high at a given temperature). However, heaters that are used with high pressure to provide heat to the room must apply a pressure of about 138.5 inches of water column (especially heaters that operate with both natural gas and propane). The heaters that are commonly used in poultry farms today are those that operate at low pressure. The reason for this is that most breeders are not equipped with the necessary facilities in their breeding halls, and their repair and service require special skills.
Radiant Systems
These types of systems that breeders use in breeding halls are open flame heating systems, meaning that their flames are visible and air is supplied from inside the building to provide oxygen. In this section, we will try to talk about radiant systems whose flames are visible.
Type 1: Circular radiant heating system
Type 2: Rectangular radiant heating system
It should be noted that the most common type of system is the circular radiant system (Figure 1). Circular heat supply systems (artificial mothers) are most often installed above the feeder and waterer system to provide a suitable and comfortable environment and to stimulate the chicks to consume food.
In halls 76 meters long and 12 meters wide, at least 14 artificial mothers (radiant heating systems) are required to heat the hall (Figure 2). The number and size of the above systems (based on input BTU – the British Thermal Unit used to measure heat, defined as the amount of heat required to raise the temperature of one pound of water (453 mg) by one degree Fahrenheit (34 degrees Fahrenheit is 1.11 degrees Celsius)) will vary depending on the breeding system and should be spaced 8 to 12 meters apart and 2.30 centimeters above the litter. It is important to note that they should be installed in a way that does not interfere with personnel and daily operations.
The components of the artificial brooder system include an aluminum plate, a fuel-fired heat source, and a hanging hook. The aluminum plate can be made of stainless steel that reflects heat to the chicks and their diameter can vary from 79 to 100 cm and the temperature of the inner crown surface of the artificial mother varies from 93 to 204 ° C. The size and shape of the heat emitter of the artificial mother varies by manufacturer, but all of these systems provide the heat needed to raise birds. Usually the heat producing burners are cast iron type that are used to control the heat and distribute the heat evenly to warm the bird space. Most circular artificial mothers are available in two types of pilot and direct spark. In the ignition system using a direct spark, a high-voltage electric arc is created between two electrodes and causes a light gas to flow through the burner. The important and practical point here is that the fuel required to provide the spark for the heat of the artificial mother is not used continuously and this type of system can save between 377 and 126 kilocalories (4 BTUs equal 1 calorie) in energy consumption per hour and this time makes it economical in energy consumption when the breeding hall does not need additional heat and all systems have taken into account safety issues in the construction of systems to prevent fires in the hall to prevent any accidents.
Plate artificial mothers are thermally evaluated and operated by a thermostat (thermal transistor) that has an internal thermal detection sensor. A thermistor (thermal transistor) can control and manage four heating systems and only turn on the places that need heat and the heating system starts working in that position. Of course, the behavior of the chicks should always be examined in the field to provide the desired and required heat, and the criterion and validity of these systems are determined by the behavior of the chicks. Visible flame systems can provide about 80,000 BTU of heat (a unit of measurement of thermal energy) per hour and, as you can see in (Figure 3), create a rectangular heating pattern on the floor of the hall. Artificial brooder manufacturers recommend that in halls 12 meters wide and 60 meters long, 6 artificial brooders be considered, and for halls 12 meters wide and 76 meters long, 7 artificial brooders should be considered, and for halls 20 meters wide and 92 meters long, 14 artificial brooders should be considered. Of course, it should be kept in mind that the distance between artificial brooders in the hall is considered from 11 to 15 meters based on the desired hall and the width of the hall.
Artificial brooders are used in two types of high pressure and pressure in breeding halls. And their height from the litter is often considered to be about 2.13 to 2.74 cm. Because this heating system produces twice as much heat as the existing round (circular) heaters, this type of system should be installed at a standard height and distance from other heaters so that excessive heat does not prevent birds from consuming feed and water.
Tubular Radiant Heaters
Tubular radiant heaters are a type of closed flame heating heater (Figure 4). This type of heater requires air from outside the room for internal combustion to produce heat. The heater flame is enclosed in a tall metal box and a fan heats it, and the combustion gases in it transfer heat to the room through the tube. The exhaust gases are discharged inside the room and then transferred to the outside of the room by the ventilation system. The amount of heat produced per hour for these heaters is about 50,000 to 150,000 BTU. These types of heaters should usually be installed 6 to 18 meters apart in the room. The key point is that since these types of heaters must be installed on the ceiling and in the center of the house, their distance from the point where they are installed should be 25 to 30 cm. This type of system heats a larger cross-sectional area of the house and requires fewer of them than other systems. Unlike other heating systems that need to be lowered every time, this type of system is a separate operation.
The temperature near the combustion box tube can reach up to about 537 ° C and provides a temperature of 176.6 ° C up to 12.20 cm away from the heater. At this time, the ceiling reflectors direct less heat towards the chickens. Two important components for reflecting thermal energy to the floor surface
are: 1- The installed height of the heater 2- The surfaces of the reflectors
Tubular heaters must be able to distribute heat to the water and feed lines. This type of heating system tends to distribute heat more evenly across the bedding and starts heating the brooder area in an oval shape from the combustion box. This type of system, like radiant heaters, creates temperature ranges that the birds can choose to stay in for their own comfort.
Some tubular heaters have two heating stages and can operate at both low and high levels. The first stage, which starts with low levels, produces about 75,000 BTUs of heat energy, and the higher levels produce about 125,000 BTUs of heat energy. (An important question that may come to mind here is when do these types of heaters use these two heat levels?) Most of the year, these types of heaters use the first type of level, which has a lower heat energy output, but the higher heat level is only used during very cold days of the year. The low-level heating type saves energy because it has fewer on-off cycles and a longer heating time (the more on and off, the more fuel is used). When a tubular heater is first started, the tubes must be heated to the desired temperature in order to provide the temperature.
Heaters with a radiant tube system with a lost gas pressure and a direct spark ignition system are the most common types of heaters. One of the important things in setting up the aforementioned heaters is usually 6 meters apart and a height difference from the bed (distance from the floor of the hall) and 3.60 cm. An important and essential point in relation to these types of heaters is that their temperature regulation system is near the floor of the hall, which you should align their thermostats with the center point of the heater and hang it up to a level of 30.5 from the floor of the bed, and in the meantime, try to be between the water and feed lines.
However, the weakness of the (tubular) and rectangular radiant systems is that whenever one of them is out of operation, approximately 25% of the total heat entering the house is lost, which can lead to the house becoming cold and the birds getting sick, and creating wet bedding (Figure 6).
The heat capacity of tubular radiant heaters (which are between 2.5 and 6 meters long) is between 40,000 and 90,000 BTU per hour and their fuel source can be natural gas or propane. These types of heaters, which are in the shape of a Latin V, also include two heating stages. The recommended installation of these types of heaters in houses with a width of 14 meters and a length of 76 meters is 6 units. And it depends on the age of the birds (the distance between the heaters is the same as above).
Hot Air Heaters
The heaters used in breeding halls provide between 30,000 and 325,000 BTU of heat energy per hour. These types of heaters use the energy from fuel combustion to heat the air in the hall and distribute the heat through the hall with pressure. These heaters are usually installed on the side wall of the hall (of course, they are installed in the middle of the hall on four legs with a certain height) to distribute the heat produced throughout the hall.
In the meantime, in the hall we will have different thermal temperature levels from the ceiling of the hall to the bed (thermal stratification) and due to the temperature difference that exists for heat, the points closer to the ceiling are warmer. We use agitator (circulator) fans to remove the hot air trapped in the ceiling and direct it to the lower parts so that the heat can reach the bed of the hall. Typically, three or four low-pressure gas heaters with a capacity of 225,000 to 250,000 BTU are required for young chicks. Most models operate at about 60 percent of their full capacity.
Conclusion
The first question that comes to mind when considering heating systems for breeders is:
Can the existing heaters provide a suitable thermal environment that will improve the performance of the birds?
How much will it cost to create a suitable and desirable environment for the birds?
Keep in mind that 19 cubic meters of propane gas is used per year to heat a breeding house.
In recent years, radiant heaters have become more widely used, as they cover a larger area in terms of heat output, making them more cost-effective.
