poultry climate control

1 - Temperature and humidity sensors: Four NTC temperature sensors and one humidity sensor is installed in each poultry house. In this section, value of each temperature sensor is shown. There is a color bar above each temperature value which indicates temperatures condition as bellow:

Green: Normal value
The value of the temperature is in the normal range defined for each sensor. Definition of the sensor limits will be explained later in section ‘advanced settings’ of this document.

Red: High value
The value of the temperature is in higher than defined limits.

Blue: Low value
The value of the temperature is in Lower than defined limits.

Yellow: Damaged sensor
When there is a problem in reading the value of sensor, the color bar changes to yellow. May be the problem is from cabling, connections or the sensor itself. To prevent detrimental effect on the condition of the house climate, the value of the damaged sensor is replaced by the average temperature value. So sensors failure doesn’t cause a any risk in broilers performance. Failure Detection of sensors is defined by some value limits which would be explained later in this document. The average temperature (حراره المتوسط) is calculated by adding 4 temperature values and dividing it by 4. The humidity value of the house is read from the SWD sensor which is installed in the middle of the house. The sensing element is the SENSIRION SHT10 which its technical data is presented in appendix A.

2- Birds age and Target temperature Target temperature (درجه المطلوبه) is the temperature set point. All temperature dependent equipment operates based on this value. So the climate control system tries to set the house temperature to this point by running supplemental heating system when the inside temperature is less than target temperature and running cooling system when the inside temperature is higher than target temperature.
As explained in broiler environmental management documents, the target temperature should be regulated by the farmer based on the flock behavior. The climate control system sets the target temperature automatically based on birds age and inside humidity and some other parameters. But note that the tuning of the target temperature should be done by the farmer based on his observation of the bird behavior.
For doing this, by touching the target temperature (درجه المطلوبه) value, a window with an input for changing the target temperature is displayed as shown in figure 2. Enter the new value and press “done” button.
Note that a password is needed for changing all variables in this system. Click on the phrase "lock" in the right above corner of the main page to display the password window 3). Then enter the password and click “done” button. Now you can enter the target temperature new value.
Note: All temperature and humidity values must be entered in tenths of a degree in this system. For example, 34.2 must be entered as 342, 33 must be entered as 330 and 65% must be entered as 650
To prevent human error, input values are limited to an acceptable range. For example, the system doesn’t allow you to change the target temperature of day one, above 36.0 and below 28.0 degrees Celsius. Method of changing these limitations will be explained later in this document in section “Variables”. As mentioned before target temperature in this system varies automatically based on birds age. This is done by function number 2 named dayTemp. More details about FUNCTIONs will be explained later in section “advanced settings”, but for now you can just check the function dayTemp as below:

Setting >> password >> functions >> dayTemp (2) >> edit

As you can see, the function is a piecewise linear one with the ageday1 as input. So it checks the birds age as input and produces a minus number as below:
So if you set the first day target temperature to 33.0, this function will decrease it to 31.0 for age 10. Also system interpolates values between table columns. For example, for day 25, dayTemp function output would be about
-45, so the target temperature is 28.5:
Target temperature = 330 – 45 = 285

Please note that all temperature and humidity values are considered in tenth of a degree. 28.5 is considered and calculated in this system as 285. Target temperature also depends on outside temperature to prevent cold air drop when outside temperature is so low. This dependency is done by function number 28 named outtarget, you can check this function as follows:

Setting >> password >> functions >> outtarget (28) (2) >> edit

Again it is a piecewise function with outside temperature as input:

As you can see in above table, when outside temperature is lower than 7 degrees Celsius, the target temperature increases 0.5 degree Celsius.
Setting the start date: The start date of brooding period can be defined for each house separately. Set the start date as follows:

Setting >> password >> Start Date.

Press “now” button to set the start date to today or set any date as start date by entering year, month, and day as shown in figure 5. The “clear” button will clear all logger data related to this house. Logger will be explained later in this document in section “advanced settings”
3- Outdoor temperature and humidity (درجه الحراره و رطوبه الخارجیه) Value of outside temperature and humidity is displayed in this part of main page. These values are read from an outside sensor which uses SHT10 sensor element by Sensirion. The main effect of outside temperature is on total ventilation calculation. This effect is described later in this section. Outdoor humidity is displayed as percent of relative humidity (%RH). System decides to apply minimum, transitional or tunnel ventilation based on outdoor temperature. Therefore, the correct operation of the outdoor sensor is critical in the proper operation of the ventilation system.

4- Number of birds (عدد الطیر) The flock number of chickens affects the amount of minimum ventilation. System calculates the amount of minimum ventilation based on birds age and number of birds available in the house. So in addition to setting the start date, the number of birds must be entered correctly in start of each brooding period. To do this, click on the value of (عدد الطیر). A window for entering number of birds is displayed as follows:

Enter the new number, and press “done” on the keyboard. Now press “Done” button on the left bottom side of window.

To prevent human error, this number is restricted in range of 8000 and 15000 based on your house size and capacity. Obviously, these limitations are changeable and the method of changing is explained later in this document.

As mentioned before, a password is needed for changing all variables in this system. If the system is locked, click on the phrase "lock" in the right above corner of the main page to display the password window (figure 3). Then enter the password and click “done” button. Now you can enter the number of birds new value.

Number of mortalities (هلاکات):

In addition to entering the initial number of birds in the start of brooding period, the number of mortalities can be entered day by day. This helps the farmer in analysis of poultry welfare and health. The remaining number of birds is shown in (طیر الموجود) part. Also the percent of mortality is shown next to the number of available birds and is calculated as follows:

percent of mortality=(total number of mortalities )/(initial number of birds)*100 %

To enter number of dead chickens, click on the value of available bird number (طیر الموجود), and enter the number of mortalities (هلاکات), as shown in figure 7.

5- House schematic
A simple schematic of the poultry house is shown in right side of main page as shown in figure 1. Heaters and fans positions and status are illustrated in this simple schematic. As can be seen in the schematic, there are 2 heaters, 4 small fans and 5 big fans in each house. The status of each fan and heater are shown as follows:

Green: Switched on

If the equipment is switched on

It’s color changes to green.

Note that the green color just means that the system has issued turn on command. If there is any problem in cabling, electrical cabinet equipment and so on, the system cannot detect it, unless it has an error detection system(EDS).

White: Switched off:

If the equipment is switched off, It’s color changes to white. Note that the white color just means that the system has issued turn off command. If there is any problem in cabling, electrical cabinet equipment and so on, the system cannot detect it, unless it has an error detection system(EDS).
Yellow:Damaged
If the equipment has an error detection system(EDS) and EDS detects a failure in equipment, its color changes to yellow. Big fans in your house have EDS system.

As you can see in figure 8, there is a number next to each big fan. This number is the rotation speed of fan in RPM. These RPMs are read from error detection system (EDS). It uses electromagnetic sensors (Hall effect sensors) to measure rotation speed of fans. EDS can detect any failure in electrical equipment, cabling, belt or motor which causes the fan not to rotate in predefined speed when the turn-on command is issued from the climate control system

Total ventilation:

In the middle of the house schematic, amount of total ventilation (تهویه الکلیه) is shown in m3/min. Here we are not going to talk about the method of calculation of this number, but it’s important to know how this amount of ventilation is applied in the house. There are 2 types of fans in each house:

Four Small fans with capacity of about 9000 m3/hour or 150m3/min

Five big fans with capacity of about 36000 m3/hour or 600m3/min

Small fans speed is controlled by an inverter driver. So the total capacity of small fans is about 36000 m3/hour or 600 m3/min.

The procedure is as follows:

If the total calculated ventilation is less than 600 m3/min, this is provided by small ventilators and inverter (سرعه). Minimum value for inverter output frequency is 20.00 Hz. For example, if the calculated ventilation is 300m3/min, the inverter speed would be about 25.00 Hz. Take note that all small ventilators contactors are turned on and the speed is controlled by inverter. So the small squares in house schematic (small ventilators) are always green, showing they are switched on, and speed is speed is controlled by inverter (سرعه).

If total calculated ventilation is more than 600 and less than 1200, a big fan is switched on and small fans speed are controlled by inverter again.

This process will continue in the next steps as well. Each big ventilator 600 m3/min and inverter 600 m3/min.

As shown in figure 8, the total ventilation is 906 m3/min. all small ventilators are switched on (green small squares), one big ventilator is switched on, and inverter output has a value of 18%. This value causes a frequency of about 25.00 Hz in inverter. Because the big ventilators have EDS, rotation speed of working ventilator is shown in the schematic.

Note: 50.00 Hz in inverter is maximum frequency of main power supply and causes fans to work in its nominal speed. The relationship between the ventilator and the frequency in the allowable range is almost linear.

By the way, the amount of total ventilation can be tuned based on famer observation of birds’ behavior, litter quality and air quality.

For doing this, by touching the total ventilation (تهویه الکلیه) value, a window with an input for changing the total ventilation coefficient is displayed as shown in figure 9. Farmer can change the total ventilation by changing this coefficient. Entering number 100% means that total ventilation is applied as calculated by the system. For decreasing total ventilation about 10%, enter 90% for (تصلیح تهویه الکلیه) and for increasing total ventilation about 10% enter 110% for (تصلیح تهویه الکلیه). After entering the new value, press “done” button.

Inlet opening:

Inlet windows are controlled by electronic winches. These winches accept a 0-5v input voltage. Analog outputs range of climate control system is 0-10v. so setting the output to 50%, causes inlet windows to be opened completely in whole calibration range. Analog outputs and their settings will be explained later in section “advanced settings”.

The amount of opening of the inlet windows is proportional to the amount of ventilation. This number is shown as (مدخل الهواء) in the main page.

you can change the amount of opening inlet windows. For doing this, by touching the value of (مدخل الهواء), a window with an input for changing the inlet coefficient is displayed as shown in figure 10. Farmer can change amount of inlet windows opening by changing this coefficient. Entering number 100% means that amount of opening is applied as calculated by the system. For decreasing inlet opening about 10%, enter 90% for (تصلیح مدخل الهواء) and for increasing inlet opening about 10% enter 110% for (تصلیح مدخل الهواء). After entering the new value, press “done” button.

As mentioned before, the amount of opening of the inlet windows is proportional to the amount of ventilation. This is done by function number 9 named inlet, you can check this function as follows:

Setting >> password >> functions >> inlet (9) >> edit

Again it is a piecewise function with total ventilation (تهویه الکلیه) as input:

As you can see in above table, when outside total ventilation is 650 m3/min, the inlet opening is 18 (36%) and so on. Interpolation is done between the table columns. For example, for total ventilation about 900, opening is calculated about 24 (48%).

6- Ventilation settings (التنظیمات) By clicking button “التنظیمات” in the left bottom corner of main page, ventilation setting page is displayed as shown in figure 11.

For better understanding these settings, we should know some basics of minimum and transitional ventilation, and the method of their implementation in this system. All parts of calculation are changeable but it would be better done after studying section “advanced settings” of this document. For now, we just describe the basics and check the implementation methods without careful review of details.

Ventilation calculations:

With a background in poultry ventilation knowledge, we know that there is a minimum amount of ventilation needed for each bird in any age. There are several tables available for minimum ventilation based on birds age, outdoor temperature, inside humidity and some other parameters. As mentioned in ventilation documents, none of these tables are practical for all poultry house conditions and always there is a need of tuning based on behavior, welfare and health of flock.

We have used one of these minimum ventilation tables in your farm which says a minimum of 0.015 m3/min of fresh air is needed for each kg of alive birds in the house. In addition, as mentioned in Ross0308 documents, if we have a ventilation about 2 cfm for each kg of alive birds, the inside temperature doesn’t exceed more than 2 degrees Celsius above outdoor temperature. This is a vital note for transitional ventilation. In other words, if we have 2 cfm/kg (~ 0.06 m3/min/kg) ventilation rate, all metabolic heat is exhausted out from the house. So we call this calculated ventilation rate as “transitional ventilation rate”. Based on Ross0308 performance objectives, for 10,000 of birds, the transitional ventilation rate can be calculated as follows: As you can see in the above table, the intended weights are above normally achievable values. So usually some tuning is needed. Above calculations are done in function number 3 named vent10000. You can check this function as follows:

Setting >> password >> functions >> vent1000 (3) >> edit