Hired-Hand

Frequently Asked Questions
What is a house tightness test and how is it conducted? A good rule of thumb for checking a broiler house for tightness is to close all the inlets and doors in the house and turn on one tunnel fan and observe the static pressure difference between inside and outside of the house. The higher the static pressure difference the tighter the house is. Field tests and observations have shown many broiler houses to have a static pressure under this tightness test of under 0.03 to 0.05 inches of water (7.5-12.5 Pa). New houses that are being built where builders are paying special attention to minimizing leaks and tightness can have static pressure readings of 0.15 to 0.25 inches (37-62 Pa) during this tightness test. The performance difference in these houses from a ventilation standpoint is staggering. Loose houses use much more fuel, have poor litter quality, and less uniformity in temperature and air quality for the birds. Field results have shown that houses that have leak test readings as low as 0.03-0.05 inches (7.5-12.5Pa) will use 20-25% more fuel than those with leak test readings of 0.15 inches (37 Pa). Product Categories: Ventilation, Structures Industries: Poultry
Are there any reliable guidelines for knowing whether a broiler house should be in tunnel ventilation or not? It's not an exact science, but yes, there are some useful guidelines here. The basic principle is to go into tunnel ventilation only when the transitional setup cannot keep up with the need for heat removal. It's easy to forget that running half of the tunnel fans in transitional mode removes just as much heat as running the same fans through the tunnel inlets. So if the job can be done in transitional mode with fewer than half the tunnel fans, stay with that. If it's too cool outside for the age of the birds, tunnel can hurt more than help. Some guidelines: If outside temperature is less than 70 F (21 C) and birds are four weeks or younger, house usually should be in transitional (or minimum) mode. If outside temperature is 65 F (18 C) and birds are 5 weeks old, stay in transitional. If outside temperature is 60 F (15.5 C) or lower with any age birds, stay in transitional mode. Product Categories: Ventilation Industries: Poultry
Considering the cost of installing equipment such as vent boxes and power vent machines, why shouldn't I consider just going with curtain or board cracks as inlets for minimum ventilation? Just a few years back, using curtain cracks and then board inlets with power ventilation was certainly an improvement over natural ventilation, without fans. Today, however, this technology is no longer competitive in many parts of the world. Curtain or board cracks must be controlled manually, if they can be controlled at all. The chief drawback, however, is that they do not allow adequate control of the incoming airflow direction and therefore air mixing in the house. Incoming dense or heavy cold air tends simply to drop toward and chill the birds. Over the life of the equipment, the flock performance gains from much more precise and automatic control of the incoming airflow more than justify the investment costs in most market conditions. Product Categories: Ventilation
Could running water lines and electrical conduit along the house ceiling possibly hurt the effectiveness of my ventilation system? Yes, indeed. During minimum or transitional ventilation, we want incoming air to stream along and hug the ceiling as long as possible, in order to get good air mixing. If pipes and conduits are placed on the ceiling above air inlets they can appreciably obstruct that good airflow stream, cutting its velocity down and directing outside air downward toward the birds. Alternative locations for water lines and electrical conduits should be found. Product Categories: Ventilation
Do litter treatments have any significant impact on ventilation management? One of the most significant things that has happened in the poultry industry in the past five years that has impacted on how we run minimum ventilation is the development of litter treatments to inhibit the formation of ammonia. Proper use of a litter treatment reduces ammonia formation during the early stages of the growout. Therefore, we do not have to ventilate for ammonia control, but only for moisture removal and air quality maintenance. This translates into significant fuel savings, especially in colder weather. Product Categories: Ventilation
How do I decide when evaporative cooling should be turned on? Evaporative cooling should be turned on before heat build-up begins to hurt bird performance. It is easier and better to keep heat build-up from happening than to try to reduce the heat load after it has progressed too far. For fully-feathered birds, this usually means turning on evaporative cooling when temperatures get into the 80- to 85-degree F range (27 C to 30 C). Growers also should realize that evaporative cooling does not have to be delayed until the house is in full tunnel with all fans running. This can be especially important with younger birds, which are more sensitive to wind-chill. Using fewer fans reduces the wind speed, and evaporative cooling is more efficient when run with slower air speed, so that you can get the same effective cooling at lower cost. Product Categories: Ventilation
How do I determine how many perimeter inlets should actually be in use during brooding vs. whole-house ventilation, cold vs. cool to moderate weather, etc? The key point to realize here is that to provide the good airflow "throw" needed during minimum or transitional ventilation, sidewall air inlets must open at least 2 to 3 inches (5-8 cm) and ceiling inlets must open at least 1 to 1.5 (2.5-4 cm) inches. If the vent boards are not opened wide enough, the incoming air just sort of leaks into the house at the inlets and then falls to the floor. This definitely will happen if we are using too many inlets for the number of fans running. In this situation, the static pressure vent box machine will have to choke the inlet openings down too far in order to maintain static pressure. Typically, during the early days of a growout when we are using only one tunnel fan (or two sidewall fans) at most, we need to latch closed every other inlet in the brood chambers and all the inlets in the growout end. We would unlatch more inlets in the brood chamber only if we anticipated needing to run additional fans. After turnout we typically need to unlatch more inlets in the growout end as more fans are used, and then finally as we get some age on the birds we unlatch them all. The key is to make sure only enough vent boxes are used at each ventilation stage so that they can open wide enough to get good airflow. Product Categories: Ventilation
How important is house tightness in doing a good job in ventilating under wintertime conditions? Nearly all of the environmentally controlled poultry houses in the United States operate under the principle of negative pressure ventilation. This means that a slight suction or vacuum is placed on the house by the ventilating fans. Thus air is sucked into the house through any available openings because it is flowing from a slightly higher pressure area (outside) to a slightly lower pressure area (inside) the poultry house. This makes it possible to have air enter the perimeter of the house through carefully designed inlets that are an essential part of the ventilation system. But this works only if the house is otherwise tight, with few or no air leaks or "unplanned inlets." One of the key conditions that must be met to successfully operate a negative pressure ventilation house is that the house must be tight. In the last three years in the United States there has been a great push on to tighten up houses. Houses that have lots of air leaks through the curtains, doors, pad rooms, or ceilings have a lot of air entering the house that is not directed properly. Curtain flaps, seals on doors, patching of ceilings and in general tightening up houses have resulted in much more uniform air entry and therefore higher litter quality and uniformity of temperatures within the house. In addition, stopping or closing unplanned inlets (leaks) will greatly reduce fuel costs. Product Categories: Ventilation
I have heard it said that the air inlet is the most important part of my ventilation system. How can air inlets be more important than fans? At least in times when birds are young and/or weather is cool, so we are running in either minimum or transitional ventilation modes, you could make a good argument that the inlets are the key to getting the job done. Of course fans must be running, and they provide the muscle for the system. But in modern negative-pressure poultry houses the air inlet provides direction. Using a static pressure sensor, the inlets adjust themselves to direct cold, incoming air into the house in such a manner that does not cause condensation or bird chilling. A properly designed modern house with static pressure-controlled inlets will bring cold air into the house at high velocity and high above the birds so that the cold outside air mixes with the warm air in the top of the poultry house to achieve the desired temperature before contacting birds. Without proper air inlets or with air inlets being used improperly, either not enough air will come in, or outside air will come into the house too slowly and will drop directly to the floor. This will cause moisture condensation, wet litter, ammonia formation and bird chilling. How important is it to avoid this? Well, one University of Georgia study showed that exposing day-old chicks to an air temperature of 55 F (13C) for only 45 minutes reduced 35-day weight gain by one-fourth pound (114 g)! During brooding and cold weather, a properly designed and operated vent box or ceiling inlet is by far the most important part of the ventilation system. Product Categories: Ventilation
I have heard that the "wind-chill" effect disappears entirely when air temperature gets into the high 90s F (35+ C). If this is true, and my tunnel broiler house does not have evaporative cooling, should I just turn the fans off when the temperature goes that high? It is true that as air temperature approaches 100 F (38 C) we get much less equivalent temperature reduction or "effective cooling" from tunnel airflow. This is, however, definitely not a reason to turn ventilation off. Air must flow across birds to remove heat that is being dissipated. Without evaporative cooling, you certainly will see performance losses and higher mortalities in an extremely high temperature situation. But you are still better off removing as much heat from the house as possible, and this is what full tunnel ventilation does, whether any "wind-chill" is achieved or not. Coping with such high temperatures is possible only with evaporative cooling, which should be considered by any grower in a locale where temperatures reach this range very often or stay there very long. Product Categories: Ventilation
I know that one of the purposes of minimum ventilation is to keep in-house humidity down. But how can this work when it's raining outside? Don't worry about the rain outside. When you are running in minimum ventilation mode you can bring that rain-wet outside air in and it will be able to pick up and flush out of the house any excess moisture your birds are producing. The reason this works is that you are warming the outside air as it comes into the house and mixes with in-house air, and warming air dramatically increases its ability to hold moisture. Every 20-degree F (11-degree C) rise in air temperature about doubles the moisture-holding capacity of that volume of air. So, for example, if outside air is at say, 60 F (16C) and 90% relative humidity and you warm it to 80 F (27 C), the relative humidity will drop to only 45%. Since about 60% relative humidity is a good level for birds, the 45%-relative humidity air has plenty of room to pick up excess in-house moisture and carry it out through the fans. If the temperature difference between outside air and in-house air is larger, the drying effect is even larger. Product Categories: Ventilation
Is there any advantage in equipping a broiler house to run in tunnel ventilation mode with air velocity over 400 ft per min (2 m/s)? Yes, if you are growing a large enough broiler. USDA research has shown that increasing air velocity to 600 ft per min (3 m/s) gave only slight advantages up to the 6th week of a growout, but in the 6th and 7th weeks 600 ft per min (3 m/s) produced a significant boost in weight gain over 400 ft per min (2 m/s) airflow. Larger birds have a smaller surface area to mass ratio, which makes it harder for them to dissipate excess heat. This means that they will get relatively greater performance benefit from the high air velocity cooling than smaller birds will. It should be remembered that air velocity is not the only factor to be considered in equipping a poultry house. To be able to handle heat removal, the typical modern 40 ft x 500 ft (12 x 152 m) broiler house will be equipped with a fan capacity that will generate at least 500 ft per min (2.5 m/s) air velocity down the house. If very large birds are to be grown, even greater fan capacity and the resulting higher air velocity may be needed. Product Categories: Ventilation
Just how effective can I expect air mixing to be in my broiler house during minimum ventilation, in terms of the bird-level to ceiling temperature difference? How important is good air mixing, anyway? In modern houses with properly designed, installed and operated equipment, the bird-to-ceiling temperature difference can be kept as low as 5 degrees F (3 degrees C). In houses with inadequate equipment or poor inlet management, as much as 15 to 20 degrees F (8-11 degrees C) difference in floor and ceiling temperature have been observed. The value of having the right equipment and good management starts with saved fuel costs. Houses with poor air mixing often use 20-25% more fuel. Further, providing the right temperature and air quality from day one is critical for broiler flock performance and absolutely essential for getting top returns. Extreme temperatures can be devastating during the brooding period especially. Too cold conditions dramatically impact the ability of young birds to get adequate feed and water, and if early growth is slowed the performance losses cannot be made up during the life of the flock. Product Categories: Ventilation
Sometimes when I am running minimum ventilation the thermostat kicks the fans on so the fans are running more than they ordinarily do in minimum vent. Is this a problem? The first thing to check is whether the thermostat setting is too low. It should not be set below the target optimum temperature for that day or week. The key thing to realize is that minimum ventilation applies only when we have some combination of cool weather and/or young birds so that there is no need to exhaust heat from the house. In this situation, the primary control to regulate minimum ventilation is not temperature but the timer or time clock controlling the amount of time that fans are run to bring fresh air into the house. This can be a 10 minute or 5 minute timer or time clock feature that is built into a controller. In this situation, the thermostat is a "fail-safe" to make sure the birds don't get over-heated. As birds grow, the minimum ventilation rate (time on) is increased to take care of the increased moisture they produce. However, as the birds grow larger and/or outside temperature warms consistently, so that the birds are producing enough heat to warm or over-warm themselves and the house, thermostat control must take over. Product Categories: Ventilation
What are the advantages and disadvantages of belt drive vs direct drive fans? The decision as to whether to use direct or belt drive fans hinges mostly on how the fan will be used, which often comes down to fan size. Direct drive fans generally cost less to buy, require less maintenance, and have less performance variance than belt drive fans. Belt drive fans are more efficient for given airflow capacity, and are quieter. These differences mean that direct drive fans are used more often in smaller sizes for mixing or minimum ventilation, and belt drive for larger fans used in tunnel ventilation. For the on-off, low-volume use involved in minimum ventilation, a rugged, low maintenance, and long life fan is needed, and efficiency and maximum airflow capability may not be the main considerations. For tunnel ventilation, on the other hand, where fans are called on to move a lot of air on almost a continuous basis, the fan must be larger and more efficient, to keep the electric bills down. In this situation, the belt drive is usually the best choice. A crucial point to keep in mind, however, is that the belt drive fan will deliver cost-saving high efficiency only if the belt is regularly checked, adjusted, and replaced as needed. If the required maintenance is not going to be done on belt drive fans, direct drive fans might have been a better choice. Product Categories: Ventilation
Is it really worthwhile to take the trouble to pre-heat a house before chick placement? Yes, it definitely is worthwhile to pre-heat, and to provide optimum temperature throughout the brooding stage. When baby chicks come to the farm they have no ability to regulate their own body temperature, so that they will readily lose heat to the air and to the surface of the floor. And if they are too cool in the early days of life they will be stunted in terms of future growth. University study after study has shown that chicks brooded at too cool temperature will suffer in feed conversion, body weight, mortality and increased incidence of ascites. This is why it is so critical to pre-heat a house to have adequate warmth in the house during the first days of the flock, and to maintain the correct temperature during the brooding period. In fact it takes almost three weeks for chicks to fully develop the ability to maintain their body temperature. If we wait until the chicks are in the house before turning on the heat, it will take a day or two for the floor and the litter to warm up, and during this time the cool litter will in a sense "suck" the heat out of the chicks. It is a very good idea to pre-heat the house for at least 24 hours prior to placing chicks. The litter should be at least 85 F (29 C) at the time chicks are placed. In extremely cold weather, or if furnaces are the only heat source used, it might take 48 hours of pre-heating to obtain adequate temperature to properly receive chicks. Most companies have temperature regimes they recommend for the type birds that are grown, and these regimes should be followed. Product Categories: Heating
What are the most important signs that birds are too warm or too cold? When birds are too warm they migrate to cooler or higher airflow areas, hold feathers closer to the body, droop or lift their wings to get more air cooling, drink more and eat less. If they stop eating and begin panting, especially if normally pink skin areas turn dark red, they definitely are over-heated. When birds are too cold, they tend to huddle together on the floor, move away from the direction of air movement, and "fluff" feathers to increase their insulating value. Product Categories: Heating
What is the best method of heating to use during the brooding phase, house furnaces or some type of brooder heaters? This is a topic that is frequently discussed by growers and live production personnel. While it is possible to do a good job of brooding with furnaces, pancake brooders, and/or radiant brooding equipment, there are some distinct advantages or disadvantages to each. Using furnaces only saves the cost of the brooders, but has the disadvantage of having to heat the entire house (or partial house) to the exact air temperature needed for the birds to be comfortable. If we miss getting the right temperature, or for birds slightly ahead or behind the others who would do better at a slightly different temperature, there is nowhere for birds to go to get comfortable. Using furnaces only also means that pre-heating is even more important. Many growers are successful in brooding with furnaces only, but the consensus of most live production people is that using some type of brooders, along with furnaces for "background" heat, provides a better environment for the bird than relying only on furnaces. The primary advantage of brooders is that they produce graduated warm areas throughout the house so that there will be zones under each brooder where each chick has a choice of where to position himself. These comfort zones under brooders give the bird the opportunity to move in and out with respect to the brooder to achieve a comfort level that is perfect for that individual bird. Product Categories: Heating
What is the difference between infrared and conventional brooder heating? There is a lot of misunderstanding about how infrared heat warms a broiler chicken or a broiler house. Infrared heat is the kind of heat that comes from a glowing brooder. It is the same kind of heat that we experience when we stand in front of a fire on a cold winter day. Even though the air temperature between our bodies and the fire is cold we still receive warmth from the glow of the fire. Conventional pancake or jet brooders will produce some infrared heat, but most of their heat output is by convection, heating the air. Infrared brooders, which are usually larger physically and in heat output, provide most of their heat as infrared and therefore do not directly heat the air in the poultry house. The infrared heat is transferred from the glowing brooder to the broiler chicken (and to whatever area of the litter that is exposed) without heating the air in between. The warmed surfaces then release heat to the air and air temperature will go up. This can make infrared more efficient. One of the problems with relying on infrared heat is that since it doesn't directly heat the air itself, we do not have good methods to control it. If we use air temperature thermostats to turn infrared heaters on and off we may not be controlling the heat based on the birds' needs. As with conventional brooders, the birds have some control in that they can move in and out of the warming zone. They should be observed, however, to see if they are either packing very tightly in the warming zones (probably not getting enough warmth) or trying to scatter away from the brooders (too much heat). Product Categories: Heating
How do I decide when evaporative cooling should be turned on? Evaporative cooling should be turned on before heat build-up begins to hurt bird performance. It is easier and better to keep heat build-up from happening than to try to reduce the heat load after it has progressed too far. For fully-feathered birds, this usually means turning on evaporative cooling when temperatures get into the 80- to 85-degree F range (27 C to 30 C). Growers also should realize that evaporative cooling does not have to be delayed until the house is in full tunnel with all fans running. This can be especially important with younger birds, which are more sensitive to wind-chill. Using fewer fans reduces the wind speed, and evaporative cooling is more efficient when run with slower air speed, so that you can get the same effective cooling at lower cost. Product Categories: Evaporative Cooling
I have heard that the "wind-chill" effect disappears entirely when air temperature gets into the high 90s F (35+ C). If this is true, and my tunnel broiler house does not have evaporative cooling, should I just turn the fans off when the temperature goes that high? It is true that as air temperature approaches 100 F (38 C) we get much less equivalent temperature reduction or "effective cooling" from tunnel airflow. This is, however, definitely not a reason to turn ventilation off. Air must flow across birds to remove heat that is being dissipated. Without evaporative cooling, you certainly will see performance losses and higher mortalities in an extremely high temperature situation. But you are still better off removing as much heat from the house as possible, and this is what full tunnel ventilation does, whether any "wind-chill" is achieved or not. Coping with such high temperatures is possible only with evaporative cooling, which should be considered by any grower in a locale where temperatures reach this range very often or stay there very long. Product Categories: Evaporative Cooling
Considering the cost of installing equipment such as vent boxes and power vent machines, why shouldn't I consider just going with curtain or board cracks as inlets for minimum ventilation? Just few years back, using curtain cracks and then board inlets with power ventilation was certainly an improvement over natural ventilation, without fans. Today, however, this technology is no longer competitive in many parts of the world. Curtain or board cracks must be controlled manually, if they can be controlled at all. The chief drawback, however, is that they do not allow adequate control of the incoming airflow direction and therefore air mixing in the house. Incoming dense or heavy cold air tends simply to drop toward and chill the birds. Over the life of the equipment, the flock performance gains from much more precise and automatic control of the incoming airflow more than justify the investment costs in most market conditions. Product Categories: Controllers
How do I determine how many perimeter inlets should actually be in use during brooding vs. whole-house ventilation, cold vs. cool to moderate weather, etc? The key point to realize here is that to provide the good airflow "throw" needed during minimum or transitional ventilation, sidewall air inlets must open at least 2 to 3 inches (5-8 cm) and ceiling inlets must open at least 1 to 1.5 (2.5-4 cm) inches. If the vent boards are not opened wide enough, the incoming air just sort of leaks into the house at the inlets and then falls to the floor. This definitely will happen if we are using too many inlets for the number of fans running. In this situation, the static pressure vent box machine will have to choke the inlet openings down too far in order to maintain static pressure. Typically, during the early days of a growout when we are using only one tunnel fan (or two sidewall fans) at most, we need to latch closed every other inlet in the brood chambers and all the inlets in the growout end. We would unlatch more inlets in the brood chamber only if we anticipated needing to run additional fans. After turnout we typically need to unlatch more inlets in the growout end as more fans are used, and then finally as we get some age on the birds we unlatch them all. The key is to make sure only enough vent boxes are used at each ventilation stage so that they can open wide enough to get good airflow. Product Categories: Controllers
I understand that integrated electronic ventilation controllers can give better control of the in-house environment, but just how important is this to broiler flock performance? Our modern broilers have a genetic potential for weight gain and feed conversion that just cannot be realized without consistent, on-target temperature control. The answer, then, is that integrated controllers have high payoff potential for any grower producing modern broiler birds in a competitive market situation. Even good conventional thermostats are likely to have accuracy in the plus or minus 5-degree F (±3 degrees C) range (or even greater), where electronic control systems are capable of plus or minus 2-degree F (±1 degree C) control or better. Integrated control systems further make it much more likely that optimum environment will be maintained since they automate the process of adjusting ventilation to changing conditions. It is just impossible to achieve anywhere near that accuracy by manually setting and resetting even the best thermostat systems. The payoff? Commercial broiler companies that have closely monitored thermostat vs electronic control houses report gaining as much as four points in feed conversion by keeping temperatures within 2 degrees F (1 degree C) of optimum. Product Categories: Controllers
Sometimes when I am running minimum ventilation the thermostat kicks the fans on so the fans are running more than they ordinarily do in minimum vent. Is this a problem? The first thing to check is whether the thermostat setting is too low. It should not be set below the target optimum temperature for that day or week. The key thing to realize is that minimum ventilation applies only when we have some combination of cool weather and/or young birds so that there is no need to exhaust heat from the house. In this situation, the primary control to regulate minimum ventilation is not temperature but the timer or time clock controlling the amount of time that fans are run to bring fresh air into the house. This can be a 10 minute or 5 minute timer or time clock feature that is built into a controller. In this situation, the thermostat is a "fail-safe" to make sure the birds don't get over-heated. As birds grow, the minimum ventilation rate (time on) is increased to take care of the increased moisture they produce. However, as the birds grow larger and/or outside temperature warms consistently, so that the birds are producing enough heat to warm or over-warm themselves and the house, thermostat control must take over. Product Categories: Controllers
What exactly does the term "transitional ventilation" mean in terms of managing my poultry house ventilation? Usually, the term "transitional ventilation" refers to running some of the house tunnel fans, but bringing air into the house through perimeter inlets instead of through the tunnel inlets. This technique is ideal when we have "in-between" size birds and/or weather. In other words, we need to exhaust more heat from the house than we could with a minimum ventilation setup, but we don't want cool outside air flowing onto the birds. A good transitional ventilation setup will have enough perimeter vents to handle 50% of the tunnel ventilation capacity. Some growers now have eliminated sidewall fans entirely, and use one and sometimes two of the tunnel fans to run minimum ventilation. This tends to blur the distinction between "minimum" and "transitional" modes. The difference is that minimum ventilation is timer-controlled. When the thermostat overrides the timer, signalling that heat removal is needed, we are in transitional mode, whether sidewall or tunnel fans are being used. In most modern houses, electronic controllers manage this transition. However, the controllers themselves require good management oversight, and it is the grower who has ultimate responsibility for determining the best way to control in-house conditions. Product Categories: Controllers
What is the value of using a power vent machine as part of a ventilation system? The "power vent machine" or static-pressure inlet controller is one of the most important technological advances in poultry ventilation in recent years. It combines a static pressure sensor and inlet actuators to give you automatic adjustment of your sidewall or ceiling air inlets during cool-weather or transitional ventilation. With a power vent machine, you don't have to manually adjust inlets every time conditions change and fans kick on or drop off. A good power vent machine continually adjusts inlets to provide the precise amount of inlet opening needed to shoot air into the house fast enough and high enough to get good mixing and avoid chilling birds. It's important to realize that the power vent machine is actually controlling the house static pressure. To get good airflow through our vent boxes, we need a static pressure of about 0.08 to 0.10 inches (20-25 Pa). The vent machine senses whatever the static pressure is, and either opens up or squeezes down the inlet openings to get static pressure where it needs to be for good airflow. Product Categories: Controllers
When my house is in minimum or transitional ventilation mode with the perimeter inelts running wide open, I don't seem to be getting as good air mixing as when the power vent machine has closed the vent openings down somewhat. What could cause this? It may be that your vent boxes are opening too wide. This situation especially occurs with sidewall air inlets if the vent board is allowed to rotate past the designed "fully open" position. This is where the distance from the tip of the vent board to the inside top opening of the vent box is equal to the inlet's "throat" width or the width of the outside inlet opening. One of the purposes of the sidewall inlet vent board is to direct the incoming air toward the ceiling. If the board rotates past its fully open position toward the horizontal or even pointing downward, it will allow the incoming air to stream downward onto the birds. Some growers have thought that opening vent boards this wide would be an improvement by allowing a greater volume of air to come in, but this is not true. Product Categories: Controllers
Could running water lines and electrical conduit along the house ceiling possibly hurt the effectiveness of my ventilation system? Yes, indeed. During minimum or transitional ventilation, we want incoming air to stream along and hug the ceiling as long as possible, in order to get good air mixing. If pipes and conduits are placed on the ceiling above air inlets they can appreciably obstruct that good airflow stream, cutting its velocity down and directing outside air downward toward the birds. Alternative locations for water lines and electrical conduits should be found. Product Categories: Structures
How important is house tightness in doing a good job in ventilating under wintertime conditions? Nearly all of the environmentally controlled poultry houses in the United States operate under the principle of negative pressure ventilation. This means that a slight suction or vacuum is placed on the house by the ventilating fans. Thus air is sucked into the house through any available openings because it is flowing from a slightly higher pressure area (outside) to a slightly lower pressure area (inside) the poultry house. This makes it possible to have air enter the perimeter of the house through carefully designed inlets that are an essential part of the ventilation system. But this works only if the house is otherwise tight, with few or no air leaks or "unplanned inlets." One of the key conditions that must be met to successfully operate a negative pressure ventilation house is that the house must be tight. In the last three years in the United States there has been a great push on to tighten up houses. Houses that have lots of air leaks through the curtains, doors, pad rooms, or ceilings have a lot of air entering the house that is not directed properly. Curtain flaps, seals on doors, patching of ceilings and in general tightening up houses have resulted in much more uniform air entry and therefore higher litter quality and uniformity of temperatures within the house. In addition, stopping or closing unplanned inlets (leaks) will greatly reduce fuel costs. Product Categories: Structures