UGA Poultry Housing

Evaporative Cooling Rule # 2. With evaporative cooling you can't get more of cooling of the incoming air without increasing the humidity of the incoming air. For every 1 F cooling the Rh of the air passing through a pad will/must increase approximately 2.5%. This is true of wet pads, damp pads, pads on a timer, partially wetted pads, pads in Georgia, Alabama, California, Latin American, SE Asia....its just the way it works...after all it is called evaporative cooling : ) . Therefore the only way to minimize the RH of the air coming in to a house is to cool it less. This is most easily accomplished by simply setting a higher set point for the evaporative cooling circulation pumps.

The use of 8" PVC pipes as a pad system reservoir is more problematic than many realize. A 50' long, 8" PVC pipe filled 4" to 5" has a water holding capacity of 75 gallons (keep in mind the pad takes about the two 2" out of the pipe). A 50' pad system pump should be capable of circulating at least 40 gals/min. This means that pump will run dry in about minute or two...before the water flowing over the pad has a chance to make it back to the reservoir. Furthermore, the limited water holding capacity of the reservoir will lead to minerals building up in the sump water relatively quickly which will increase the likelihood that minerals will build up on pad surfaces. Ideally, 50' system would have a capacity of at least 150 gallons.

Why controlling the cooling produced by a pad is so very difficult? A 5' X 1' X 6" pad consists of roughly 48 pieces of paper 5.5' tall by 6" wide. Each piece of paper has essentially a total surface area of 5.5 ft2 (5.5' tall by two sides each 6" wide). As a result each 1' wide section of 5' tall pad has a total surface area of roughly 268 ft2. A single 50' X 5' pad system would have a total surface area of 13,400 ft2. Four 50' X 5' systems on a house = 53,600 ft2 or rou...ghly 1.25 acres of surface area. Within 30 seconds the circulation pumps can deliver roughly 100 gallons to the pads systems. Since the pad is constructed of highly wickable paper...over the next five minutes or so, much of the water will be distributed over the 1.25 acres of pad surface area....even if the circulation pump is turned off after operating 30 seconds or so. On a day when it is 90 F and the Rh is 50% approximately 9 gallons can evaporate from the 1.25 acres of pad surface area each minute. Since 100 gallons of water could be potentially be held by the pads. This means that a pad system can continue to produce essentially the same level of cooling for 10 minutes or so....even if the circulation pumps were only operated for a short period of time. See more

The chart below illustrates the pad water usage (per 100,000 cfm) for the Southeast U.S. as a percentage of time each summer. For instance, 7 percent of the time a 6" pad system will use 4 gals/min per 100,000 cfm of tunnel fan capacity operating. One percent of the time a 6" pad system will use 6 gals/min per 100,000 cfm. You might be interested in learning that 75% pad water usage will be 3 gals/min or less (per 100,000 cfm). 95% of the time pad water usage will be 4 gals/min or less (per 100,000 cfm)

Evaporative cooling is probably the most misunderstood aspects of managing a poultry house during hot weather. This is a shame because there are a number of hard and fast rules related to physics of evaporative cooling that do not change with the type of evaporative cooling system (pads, foggers, fogging pads, sprinklers) or climate that once you understand make evaporative cooling pad operation fairly straight forward. Rule #1: For every gallon of water you can evaporate i...nto the air you will "remove" 8,100 Btu's from the air thereby resulting in a decrease in air temperature. The more water you can evaporate in to the air the greater the reduction in cooling you will achieve. The temperature of the water has a negligible effect on the cooling produced. For instance if the water is 10 F cooler, the amount of heat evaporated from the air will increase to 8,183 Btu's per gallon....a 1% increase. A related rule is that to cool 100,000 cfm (the air moved by approximately four 54" tunnel fans) 1 F requires the evaporation of approximately 0.24 gals/min (again the temperature of the water doesn't really matter). So if you have four 54" fans (100,000 cfm) pulling air through your evaporative cooling pads and you are getting 10 F cooling we know that 2.4 gallons of water evaporating from the pads each minute (0.24 gals/min per 1 F cooling X 10 F cooling). If you have eight 54" fans operating and you are getting 10 F cooling...4.8 gals will be evaporating from the pads each minute (twice the air, twice the water). If you have eight 54" fans operating and you are getting 20 F of cooling...9.6 gals will be evaporating from the pads each minute (twice the cooling, twice the water). These relationships hold true EVERYWHERE on this planet :) It really doesn't matter the type of pad or the weather conditions....if you are getting the cooling (ie 1 F) you are evaporating the water (0.24 gals/min per 100,000 cfm). If you are confused....please let me know...it lets me know that I am doing a poor job of explaining the situation : ). I look forward to your comments.

https://www.wattagnet.com//43049-drinker-line-trays-can-re

Something to keep in mind if you are considering going to plastic pads. It is much harder to wet plastic pads than paper because there is very little wicking action with plastic pads. As a result you typically need more water flowing over the pads and using an interval timer will tend to result in significantly less cooling.

Evaluation of a Drinker System With or Without Trays on House Litter Conditions, Bird Performance, Health and Welfare https://www.uspoultry.org/research/resproj/PROJ_F085.html

Just posted our latest Poultry Housing Tip to our website entitled How to Minimize Litter Caking Issues at the Beginning of a Flock. "Why does litter seem to suddenly cake over just prior to turning the birds out into full house? In many cases it is simply because minimum ventilation fan settings are not being changed quickly enough to keep up with the rapidly increasing amount of moisture the chicks are adding to the litter. This often occurs because suggested minimum ven...tilation fan settings are often provided in terms of age of bird in weeks. The problem with this is that a specified minimum ventilation rate based on age of flock in weeks in a way suggests that the amount of moisture needing to be removed from a house doesn’t really change much over the course of a week. Though this may be true towards the end of the flock, where minimum ventilation rates to control moisture often change less than five percent from week to week, it is far from the truth during brooding, where due to the extremely high chick growth rates minimum ventilation rates, can increase twenty percent or more in just 24 hours. Over the first ten days of a flock, the weight of the chicks typically increase seven-fold. To obtain this tremendous weight gain, the amount of water the chicks consume increases equally dramatically. For instance, water usage increases from approximately 2 gals/1,000 chicks on the placement day to approximately 4.2 gals/1,000 chicks in just 24 hours. By Day 4, water usage increases to over 10 gals/1,000 chicks and by Day 10, 24 gals/1,000 chicks. Roughly a ten-fold increase in water consumption in just ten days. It stands to reason that as water intake increases dramatically, the amount of moisture the birds are adding to the air and litter in a house will increase in a similar dramatic fashion. Since our goal is to maintain a relatively constant, low litter moisture, minimum ventilation rates need to increase roughly proportionally the amount of water the chicks are consuming each day. For instance, if the birds drink 200 gallons in a day, roughly 200 gallons of water need to be removed from the house through ventilation to maintain a constant level of litter moisture...." You can read the entire newsletter at poultryventilation.com https://www.poultryventilation.com/system/tdf/vol33n2.pdf Please let us know if you have any questions.

Day 20 comparing in the same large broiler house (full house brooding) water usage measured by 1" mechanical water meter vs. 3/4" ultrasonic water meters (one of each type per end). There are the same number of birds in both houses as well as on both ends of each of the house. The ultrasonic water meters are still performing exceptionally well.

One of the best tools in many modern poultry house controllers is the ability to generate incremental water graphs. Daily water consumption just tells you how much water the birds drank over the course of the day. Graphing 15 minute water usage essentially shows you how the birds drank water and ate feed over the course of they day (one gallon of water = 0.2 lbs of feed...roughly). If daily water usage dips, an incremental water graphs will help you determine why.

Our latest Poultry Housing Tip discusses how what temperature you preheat your house to can dramatically affect your ability to dry the litter prior to chick placement. Preheating to lower than target temperatures, and not ventilating, can reduce the amount of water removed from the litter by hundreds of gallons. The higher the litter moisture when chicks arrive, the greater the potential for ammonia production, chilled chicks, and reduced ammonia control product life. https://www.poultryventilation.com/system/tdf/vol33n1.pdf

Just uploaded our latest Poultry Housing Tip - Ventilating Poultry Houses on Foggy Days to our website poultryventilation.com. "There is a concern amongst many poultry producers that bringing in fresh air on a foggy morning will lead to an increased incidence of litter caking. This is due to belief that the foggy air entering house through side wall inlets contains a large number of small water droplets which will end up being deposited onto the surface of the litter. Th...e concern is great enough that some producers will decrease minimum ventilation settings on foggy mornings in an effort to keep from bringing in this excess moisture. Though on the surface this practice may sound logical, though foggy air does in fact contain more moisture than non-foggy air, the difference is far less than most would believe and reducing ventilation rates on foggy mornings can in fact dramatically increase the likelihood of litter caking.. Though foggy air appears to be packed with moisture, it isn’t. First, a droplet of fog is extremely small, roughly 10 microns in diameter (0.0004")1. To put this in perspective, the typical rain droplet is approximately 2,500 microns in diameter (0.1"), 250 times the size of a fog droplet (Figure 1). Since a fog droplet is essentially microscopic, it would take roughly 200 million fog droplets just to fill the cap from a plastic soda bottle! There are approximately ten million fog droplets in a cubic foot of air. Which sounds like a lot, but since they are so small, the actual amount of water they add to each cubic foot of air is insignificant, roughly 0.0002 ounces or 0.2 ounces in every 1,000 cubic feet...." Its not the moisture you can see that causes us problems but the moisture in the air that we can't see. But if you ventilate properly, you can keep your litter dry regardless of how cold and damp it is outside. You can access the full article using the link below: https://www.poultryventilation.com/system/tdf/vol32n9.pdf

Very nice house, very nice conditions for day-old chicks.

ACRB (1950's broiler) vs. Modern broiler at 35 days of age. A picture is worth 1,000 words :)

Todavía estás a tiempo para registrarte a las sesiones en Español del seminario de clima frio de UGA/Dr Mike Czarick & Dr Brian Fairchild. UGA Poultry Housing A...gradecemos el patrocinio de AAF International AAF Latinoamérica INSCRIBETE AQUI: https://events.r20.constantcontact.com/register/eventReg See more

What's wrong with this inlet smoke test? When evaluating side wall inlet air flow patterns within a poultry house it is crucial that it is colder outside than it is inside. If there is little to no temperature difference the warm smoke produced by insect foggers/smoke emitters will not provide an accurate illustration of what will happen when your ventilating young chicks and it is cold outside. The greater the temperature difference the quicker the air entering the house w...ill drop to the floor especially if a proper static pressure is maintained. In this example the static pressure was only 0.02" (extremely low). Had it been cold outside the air would have quickly dropped to the floor within a foot or two of entering the house. But since in this case there was no temperature difference between inside and outside the house, and warm smoke was used, the incoming air just sits next to the ceiling. See more

Yes, I would have to have this in my houses if I was growing a +9 lb broiler

One of the most important aspects to keep in mind when designing a tunnel ventilation system for a high-density commercial laying house is that it is extremely difficult for the fans to pull air down the house. This graph shows the static pressure in a 54' X 500 broiler house and a 60' X 300' three floor laying house as a function of air speed. To obtain an air speed of 600 ft/min in the broiler house only required the fans to work against a static pressure of 0.11". To obtain the same air speed in the laying house required the fans to operate against a static of 0.24". Increase the laying house length or air speed and the static pressure would increase past the operating static pressure of most tunnel fans

ACRB (1950's broiler) Vs. Modern broiler at 28 days of age. Last time...no hormones. Yes...it is amazing the progress our industry has made.

What you have all been waiting for... ACRB (1950's broiler) Vs. a modern broiler at 21 days of age. Sorry I have to emphasize...NO hormones added...just good old genetic selection.

You can still register for the Cold Weather Ventilation Webinar Series. Thursday I will be speaking on the subject house tightness: 1) How to measure it. 2) Problems associated with it. 3) Tips on how to increase house tightness. 4) How to determine where leakage is occurring... 5) The relationship between leakage and litter quality. 6) How does house tightness affect the effectiveness of side wall inlets during minimum ventilation. 7) How much it is costing you in increased fuel usage. etc. https://attendee.gotowebinar.com/regist/3725350313830349581 Register now and you will have access to the first week's webinar "House Temperature and Broiler Performance. The registration fee of $40 (total cost for all eight webinars) helps support our field studies. Please let us know if you have any questions.

Registration is now open to participate in the Spanish recordings of our Cold Weather Ventilation Management Webinar Series! Let us know if you have any questions. https://events.r20.constantcontact.com/register/eventReg

Testing Choretime's new direct-drive, variable speed, tunnel fan

With end wall fans tunnel fan leakage air quickly is removed from the house. With side wall fans tunnel fan leakage air pushes warm air out the tunnel fan area of the house replacing it with colder air. One of the topics to be covered in more detail in our Cold Weather Ventilation Webinar Series.

Temperature and air flow critical to broiler performance year-round. Don't understand why they chose to use the picture they did in the article :) https://poultryhealthtoday.com/temperature-and-air-flow-c/