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Evaporative Cooling System for broiler

Forum: Evaporative Cooling System

Published: June 27, 2011
By: Munawar Ali

On a Broiler Breeder farm it becomes very difficult to keep the birds comfortable with "Evaporative Cooling System" when HUMIDITY levels are very high. Do you have any suggestion?

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Munawar Ali
Islamabad Group
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Yasser Elshami
28 de junio de 2011

Good article about Evaporative Cooling System for broiler

high air speed ? 2.5 m/s

Syed Mahmood Akhter
28 de junio de 2011
Dr. Munawer, what is the actual problem you are facing while running your farm on evaporative cooling system. The only problem I faced while at the Be Be Jan Farms was that the air speed inside the shed was very slow with the original system supplied by the company in USA. as a result the birds were uncomfortable due to humidity and wet litter. The air speed inside the shed was 200 m/sec measure with the anemometer. To correct this problem I increased the speed of the of the fans by changing the pulleys and brought the speed of the air to 410 m/sec inside the shed and the birds were very comfortable and the litter was also very dry. During the rainy season we stopped the water sprinklers and only the fans were on this worked very fine for me. If you have and particular problem due come up with it in the forum.
Stanley Kaye
SK Consultancy (SKC)
28 de junio de 2011
Dr. Akhter is right (thoigh i presume he means 2 meters per second rather than 200). The higher the humidity the lss reliance should be made on the cool pads and the more on higher air speeds.
Sardar Shahid
14 de enero de 2018
Stanley Kaye A born engineer,now a days working on high flow of ventilation systems for tunnels, Controlled sheds are expensive and evoperated system cheaper to cost but the results for the both of we compare the performance during high temperature and moister seasons then we feel evoperated system installer at risk,there is just one solution to get rid of cold/hot problems to insulate roof top with 2” thick polyurethane coating which will last for life time. Oh yes if side walls,HHAAAHAAA then lot of power bills remain in pocket. Thax for reading.
Munawar Ali
Islamabad Group
28 de junio de 2011


Thanks Dr. Mehmood and Stanley

You both are correct. Air velocity is very important. At present the air speed is 3 m/s and main problem is in high humidity. When weather is hot and humid we put on cooling pads on timer because if you stop totally then inside shed temperature will rise continuously and you may have mortality. Even with putting pads on timer birds are not comfortable. The humidity inside house sometimes touches 90 % and temperature 34 C. In this situation the heat index is high and there is no wind chill effect. Birds start panting and loose production and hatchability. In this situation only air velocity is cannot solve problem. Waiting suggestion to improve the situation.

Best regards
Dr. Munawar Ali

Marcel Waanders
15 de enero de 2018
Munawar Ali , Dear Sir, how deep is groundwater in the area,s,and which temp. has the groundwater? I may have an innovative alternative due to hot weather and humidity. best regards, marcel waanders the netherlands.
Arshaq Ramzee
28 de junio de 2011
Although I am not an expert on poultry housing but I do remember watching movies in cinemas, even in monsoon weather (high humidity with very high temperatures) we feel very comfortable in the cinema though all cinemas in Pakistan were/are using evaporation cooling system to cool the huge cinema halls. I wonder why when watching movies with full house during rainy season in summer, we feel comfortable? My opinion is that cooling systems of cinemas are build quite far from the main cinema building and they bring the cool wet air from a distance through pipes from at least 100 yards. During transfer of air from cooling fountain to cinema hall, most of the humidity was lost in the pipes supplying dry air to the main building. Perhaps, on poultry farm, a similar system may be build far from sheds, i.e., a cooling tower with water fall on pads 100 yards from sheds and then use fans and pipes to bring this cool air into the sheds and i am sure that distance of the pipes would take some humidity away from the moist air.
Dr. Naseem Chaudhry
28 de junio de 2011
That is right that in humid weather the humidity touches sometime above the 90%, make the flock very uncomfortable, In my experience when cross section area of the farm reduces with baffles and keep the birds on wind chill with the 25% extra velocity of the length of the house, gives good results, but not hundred percent.
SOHAIL BASHARAT
4 de enero de 2018
Dr. Naseem Chaudhry Baffles are basically used to increase air speed inside the house but this is for dairy barns not for poultry house because we already dealing with low air speed high RH along with static pressure , baffles are obstacles which means reduce the fan efficiency more than 20-30 percent and when your fans are already not cleaned it means add more 15-20 reduction in fans efficiency ....
Syed Mahmood Akhter
28 de junio de 2011
You can get good result by increasing the fan speeds by changing the pulley on the motor shaft. Can you give me the diameter of both the pulleys i.e the motor side and the fan side and also the RPM of the motors then I guide you how much to change in the pulley is to be made. Cell # 0300-8461046
SOHAIL BASHARAT
4 de enero de 2018
Syed Mahmood Akhter If you are putting air inside the house which have 35c temperature along with 70-80 humidity and passing this air through a cooling media it means you are adding more water in it .... so you have to know pad efficiency ? what is your running pad efficiency ? what is air velocity from outside ? than after this how you will calculate add up RH inside the building any calculation ? formula ? every one is just chasing speed how fast is fast ?? nobody is paying attention on air chemistry , entry , enthalpy , thermodynamics .....
Marcel Waanders
6 de enero de 2018
SOHAIL BASHARAT hello Sir, there are more sophisticated ways, with low areation and at least 8-10 degrees lower Temp. your comment is correct though. regards marcel
Syed Mahmood Akhter
28 de junio de 2011
There is term called "Tunnel Effect" .This effect is caused by increasing the speed of wind passing through the poultry shed. This can only be achieved by blocking all the opening on the sides of the shed and the only air passage is the cooling pads. When humidity is high the only solution is by increasing air speed through the shed. If you want any help do call me on my cell.
SOHAIL BASHARAT
4 de enero de 2018
Syed Mahmood Akhter tunnel effect will be smooth in the middle but always vary and low near to the walls and this effect goes further down as much as air travel within the house ......
Dr Jaydip Mulik
28 de junio de 2011

Evaporative Cooling with Power Ventilation

Fogging nozzles and evaporative cooling pads are options that can be used in combination with power ventilation systems and especially with tunnel ventilation. Evaporative cooling uses heat from the air to vaporize water, increasing humidity but lowering air temperatures. Evaporative cooling can be effective in during the hottest part of most days because that is when humidity is lowest. On rare occasions the humidity remains high the entire day or immediately before or after a storm; evaporative cooling is ineffective under such conditions and should not be used.

Evaporative cooling pads operate on the same cooling principle as foggers, except that the air is cooled when it passes through the wet pads as it enters the house. This method avoids the problem of wet litter sometimes encountered with foggers, allowing evaporative cooling pads to be used on a continuous basis. Aspen fiber and corrugated cellulose are two materials widely used as cooling pads. Regular maintenance is necessary to ensure long life of the pads. First, the pads must be allowed to dry out once each day. They can be dried by turning off the water supply but allowing the fans to continue running. The best time to dry the pads is in the early morning hours when the outside temperature is relatively low. Drying allows the adhesive that holds the pad together to maintain its integrity and also helps reduce the buildup of algae. To further reduce the growth of algae, an algicide can be used in the water supplied to the cooling pads. Calcium hypochlorite, ethylene dichloride, or ammonium chloride can be administered at a rate of 6 ounces per thousand gallons of water, applied once each week. In addition, the pads should be washed monthly to remove dust and sediment. The entire system should be flushed monthly to remove the mineral salts and dirt that accumulate in the pipes and reservoir.

Evaporative pads constructed of aspen or cellulose ranging in thickness from 2 to 6 inches are being used in the industry in conjunction with power ventilation systems. On a hot, dry day these pads evaporate water at a rate up to 100 gallons per minute per hundred square feet of pad surface area. Using tunnel ventilation, they can evaporate up to 200 gallons per minute per hundred square feet of pad on a hot, dry day.

Fogging systems have also been used successfully in environmentally controlled poultry houses. Fogging systems that provide a reliable fine mist and that have water filters (to keep nozzles from clogging) and also have a positive shutoff to prevent dripping can provide successful cooling without causing wet litter. The water pressure should be at least 100 pounds per square inch (psi) to achieve a fine mist; a pressure 200 psi is preferred. The volume of water that goes through the fogging system and the number and placement of the nozzles are critical design considerations. A total flow rate of up to 1 gallon per hour per thousand cubic feet per minute (cfm) of ventilation can be used in tunnel-ventilated houses.

The design of the fogging system is critical for tunnel-ventilated houses. Cross lines of nozzles that provide a "curtain" of fog across the house at various intervals are fairly effective. Nozzles or lines of nozzles should be located close together near the air inlets, then spaced farther apart along the house, ending 60 feet from the exhaust fans. Tunnel-ventilated houses can use substantially more fogging capacity (50 to 100 percent more) than naturally ventilated houses because the forced air movement is able to carry the mist.

The value of a summer ventilation system should not be underestimated. If the system is operating properly, it can improve litter quality, reduce dust levels, and improve the flock's rate of gain or production level. The key to operating any ventilation system is understanding how it works. In addition, a good maintenance program of cleaning, adjusting, and monitoring controls for the curtains or inlets will maintain system efficiency. Fans in any ventilation system should be cleaned and lubricated frequently, and fan belts should be adjusted periodically, especially during times of heaviest use. If foggers are used, they should be serviced periodically to ensure that they produce a uniform, fine fog. If questions arise concerning the operation of your ventilation system, consult your flock supervisor.

Tunnel Ventilation
A new arrangement for ventilating poultry houses in the summer is tunnel ventilation. Simply put, this method involves moving air along the building axis from inlets to exhaust fans, providing high airflow velocities. This rapid air movement increases convective heat loss, reducing the effective temperature experienced by the birds. Most of the benefits of tunnel ventilation occur at an air velocity of 350 feet per minute. This velocity should be considered the minimum for most house designs. Tunnel ventilation systems do not operate on a static pressure difference. In fact, they work best when there is no pressure difference between the inlets and the fans.

Arshaq Ramzee
28 de junio de 2011
For all the discussion, the fundamental question of Dr. Munawar remained unanswered, all the solution offered are very common and known to every production manager, but the question is how to remove excessive humidity? By increasing the speed, you replace the air more quickly but if replaced air also has the high humidity then increase in flow of air would only ease out the situation a little but you cannot avoid wet litter conditions.
Syed Mahmood Akhter
28 de junio de 2011
With Tunnel ventilation system you cannot avoid the humidity outside the shed. With increased air flow through the shed you can replace the humid air inside the shed and this is the only solution. If somebody has a bright idea then he can come up with it rather not just critising and not giving any solution.
Munawar Ali
Islamabad Group
28 de junio de 2011
Dr Ramzee rightly pointed out . My question is still there. All the respected participants mentioned very basic things. I have full respect for them but there should be some new idea to solve the problem. The above mentioned shed is modern house constructed with all calculated specifications of insulation , air velocity at pad area and complete tunnel with an air velocity more than 3 m/s. Again thanks for all. Dr. Munawar Ali
SOHAIL BASHARAT
4 de enero de 2018
Munawar Ali send me your contact details sir ..
Syed Mahmood Akhter
28 de junio de 2011
Dr. Munawer I would suggest that you just try to increase the air flow upto 4 m/sec by increasing the fan speed which you can do by increasing the drive pulley size or decreasing the pulley size of the fan shaft. It is worth giving it a try. I had tried this and it worked very well.
Ahmed Din Anjum
28 de junio de 2011
Do not use water when RH in the house is above 75-80%. Increase air circulation as much as possible ... try.
Arshaq Ramzee
28 de junio de 2011
In my opinion, only solution to reduce humidity is to use dry cooling system or you create wet cool air away from the house and bring that air through pipes to the main house, those pipes should be covered with glass wool outside. I am sure an engineer can calculate the size of pipes and distance from cooling tower to the house.
Dr Jaydip Mulik
28 de junio de 2011
Dear All , Please up date us on the correct way to resolve the problem of high humidity along with high temperature what Mr Munawar Sir facing at his premises. I am also living in such environment only & i have observed that in such drastic situation water coolers not working because already humidity is high and Fans are working but not sufficient to cool down the temperature so maximum peoples prefer to put Air conditioners in their houses. This clearly indicates that only DRY & COOL AIR will work in such conditions so my personal advise will be that in such environmental conditions when humidity is more than 80% and Temperature crosses 35 Deg.C, 1) Instead continuous use of cooling pads, run it on frequent intervals only to reduce the humidity. 2) Try to run the Fans UT most with max. speed as per specifications to blow out the hot air from the premises. 3) If those ideas are not working then Putting the central AIR CONDITIONERS in sheds is the only solution to overcome this problem.(Economics in user's hand) regards, Dr Jaydip
Rao Zulqurnain
Rao Zulqurnain
28 de junio de 2011
we can reduce the RH in the house by doing the following things 1- Selection of the Fan Fan Size,Fan CFM,Blade size,CFM/watt,Direct driven or belt driven,no of blades,Box or Cone 2- Pad Large flute or small flute (flute size) Angle of the pad, Pad size(4" or 6") 3-Static pressure of the house 4-By using slats inplace of liter(rice husk) 5-Keeping the liter dry 6-Gut health of the bird
Dr Muhammad Arshad  Manj
SB Feed
29 de junio de 2011
yes, first of all plz ensure that ; 1- fans belts are tightened ,its important for the reason that afan with loose belt will exhaust 15--20% less air 2- fans shutters are fully opened; slanty position of shutters is not desirable 3- fans blades must b free of dust all the time , especially during hot weathers, bcs a dusted blade fan efficiency is reduced to 20-25%. if after committing the aove operation there is no betterment in the comfort zone then follow this , PLZ install 20%--25% more fans to expell the moisture out , and it is working exceptionally well in areas like multan . NOTE THAT THESE EXTRA FANS WILL ONLY WORK DURING THE HOT AND HIGH HUMIDITY PERIOD OF THE YEAR .( IT is little expensive but not than birds)
Syed Mahmood Akhter
29 de junio de 2011
As I have previous said and also my friend Dr. Muhammad Arshad has indicated the only solution is to increase the speed of air replacement in the shed. This can only be done by increasing the fan speed or putting in more fans to replace the humid air at a faster speed. The method of air conditioning and other solutions put forward by my other friends are only practical in house and theatres but not workable in the poultry sheds. I would once again suggest to increase the fan speed. It is worth trying and I am sure this will definitely work for Dr. Munawer. The only expense involved is the cost of replacing the drive pulleys on the fans the increase in the pulleys will only be about one inch in diameter of the existing pulleys. I am ready to help Dr. Munawer if he wants then he can contact me on my cell # 0300-8461068
Stanley Kaye
SK Consultancy (SKC)
29 de junio de 2011
May I recommend that there are cheap and good tools that can measure temperature, wind speed and fan speed at www.poultyfarmertools.com. I use this site a lot and find it very helpful.
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