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Northwest Envirofan

A division of

Northwest Environmental Systems, Inc.

 
Toll-Free: 800-236-7080
Phone: 920-235-7808
Fax: 920-235-3049
Email:
info@envirofan.com




AGRIFAN SYSTEMS GUIDE

 

A Simplified Planning Guide

for Poultry Houses

 

The Poultry Planning Guide includes recommendations on how to achieve:

  • Better cooling in the hot months

  • Reduced condensation in the building

  • Maximum dryness to bedding litter with a reduction in a number of changes

  • A comfortable flock of birds with a maximum oxygen supply for the building dimensions

  • Drastically reduced heating costs and enhanced energy savings.

The size of building, the number of birds to be confined, plus adequate ventilation of both warm and cool air, all are part of Northwest Agrifan's Poultry Planning Guide.  Follow the steps below to create your Agrifan Ceiling Fan Layout.


STEP ONE :  PLANNING YOUR LAYOUT

NUMBER OF FANS - AGRIFAN's aerodynamically curved blades are specifically designed to maximize both floor coverage and air movement.  In poultry operations ceiling fans are typically hung on 40' centers, placed to cover the entire house area.  This area of coverage  depends on the placement of the fans within the dimensions of the house, and also on the speed of the fans as defined by their purpose, the season, and the age of the birds. 

PLACEMENT OF FANS - The general rule for placement of AGRIFANS in a poultry house is:

  • 30' - 50' wide  = One lengthwise row of AGRIFANS, centered.

  • 60+' wide     = Two lengthwise rows of AGRIFANS.

  • Optimum height = Blades 10' from floor.  Fans hung higher cover more area, but with less velocity.

  • Optimum clearance = Blades 1 1/2' to 2' from ceiling.

  • Spacing = 40' between fans (spaced on 40' centers).                    

CONTROLS - Controls for AGRIFANS should always be solid state, variable (infinite) speed controls.  Each season and/or phase of growout requires different fan speeds for maximum effectiveness. 

  • For a house divided for different phases at the same time, such as brooding and growing, the fans in each area of the house would run on a separate speed control(s).

  • For a single-purpose house one control is used for each 8 or 12 AGRIFANS.  All fans would be run at the same speed at the same time.


STEP TWO :  OPERATING YOUR SYSTEM 

FAN SPEED – The fan speed is determined by the age of the birds and whether your purpose is heating or cooling.        

HEATING – For heating different speeds are required for different ventilation modes and stages of bird growth:

  • Brooding - Chicks need temperatures at 85-90 degrees and they are very sensitive to drafts.  In the down-blowing mode (Fig. 1) AGRIFANS need to be run fast enough to push brooder heat back down, but slow enough not to stress chicks.  They can also be run in the up-blowing mode (Fig. 2) during brooding.  This way AGRIFANS will pull air up to the ceiling, mixing warmer ceiling air with cold air from the inlets and pushing this warmed air out to the sidewalls, down and across the floor. 

  • Older birds - Fans are run at a slower speed because houses are kept at lower temperatures and there is less difference between the floor and ceiling temperatures.  The purpose of AGRIFANS at this age is to achieve enough air mixing to recycle heat, keep temperatures even, and eliminate dead air pockets without creating excessive drafts on the birds.

cooling - Cooling is best achieved by fans run at higher speeds, the velocity depending on the birds' age.

  • Younger birds - Young birds are more sensitive to air movement.  For cooling, AGRIFANS should be run at as low a speed as possible that will still keep them comfortable and evenly spread out.

  • Older birds - As birds grow older hot weather creates more problems because they are getting larger.  They are insulated with more feathers, producing more heat and taking up more space.  The benefit of  AGRIFAN's vertical air flow increases with their need to rid themselves of excess heat.  Fan speed can be increased as long as the birds appear comfortable with the air movement.

HOW FAST IS TOO FAST?  It is important that AGRIFANS be run fast enough (at least 1/3 of full speed) in order to be effective.  But the birds' comfort is the best indication of proper speed.  If the birds are crowding away from the air movement, the speed needs to be lowered.  If the birds crowd toward the fans, they are trying to get cool and speed should be increased.  Ideally birds should be spread evenly.  It is also recommended that, at first, speed should be raised or lowered gradually to avoid frightening the birds.      


STEP THREE :  ACHIEVING YOUR SPECIFIC OBJECTIVES

ENERGY SAVING - AGRIFANS are designed to eliminate heat stratification.  The energy savings from this are substantial.

Without AGRIFANS during brooding, horizontally-blowing fans combined with the natural rise of hot air from the brooders cause heat to race to the ceiling at a 45 degree angle at speeds up to 200 feet per minute.   However, the vertical air flow from AGRIFANS in the downblowing mode mixes the hot ceiling air with the cold air shooting in from the inlets and pushes it down to bird level, helping to keep it from rising and escaping through the roof.  In the upblowing mode the AGRIFANS mix the hot ceiling air with the cold inlet air and it travels down the side walls and across the floor.  In both modes the heat is continuously re-used to warm birds.

Recycled heat also keeps thermostats satisfied longer.  Heating equipment will run significantly less and extend its life.  The continually circulating warm air will also pick up moisture from the litter and reduce condensation.  The exhaust fans need to run less, saving both heat and electricity.

Propane costs can be up to 40% of a grower's expense for growing birds.  AGRIFAN users report fuel savings from 20% - 50% while keeping birds warmer at floor level.  And using only .7 amps, an AGRIFAN uses five times less energy than a 1/2 hp circulating fan.  AGRIFANS can be run continuously using minimal electricity.

In order to save energy it is important that fans are run on a speed high enough to counteract the natural heat stratification.  Because of this AGRIFANS have been engineered to move air at 43,500 cfm with specially lubricated and sealed heat resistant bearings that won't dry out and lose RPM's like other ceiling fans, even when located over brooders or furnaces.

HEATING: BROODING - Downblowing vertical air flow from AGRIFANS helps keep brooder heat from rising and escaping through the roof (fig. 1).  AGRIFANS can also circulate house air by pulling cooler floor air up through the fan, mixing it with the hot ceiling air and the cold inlet air, and moving this warmer air down the sidewalls and across the floor. (fig. 2).  During brooding this not only results in big energy savings, but in continuous even temperatures for the chicks below.

AGRIFANS can be run in either the upblowing or downblowing modes, continuously or on an interval timer, depending on the growers house set-up and conditions.  If possible AGRIFANS should be run on interval timers in the ventilation fan off-time.  However, they should not stay off too long or stratification will occur and turn on the furnaces and waste heat.  House temperature stays more uniform the more the hot ceiling air and cold inlet air are continuously mixed and moved down to chick level.

This air flow also warms the litter, helping to keep the chicks more comfortable.  In the upblowing mode AGRIFANS can be run for longer periods because air velocity on the chicks is minimal.  In both modes the AGRIFAN thermostat should be located near the ceiling and set about 5 degrees above target temperature.

It is important to locate the brooder thermostat (sensor) only three or four inches off the floor where the chicks' environment is.  Otherwise the floor area and litter could be as much as 5-10 degrees colder than the 3 foot height at which thermostats are typically located.  Chilling baby chicks can result in an irreversible reduction in future bird performance.  The sensor can be raised to two feet after a week to ten days when chicks are less sensitive to lower air temperatures.

HEATING: GROWING - Because houses can now be kept at lower temperatures, the difference between floor and ceiling temperatures is not as great.  At this age the purpose of AGRIFANS is to achieve enough air mixing to recycle heat and  keep temperatures uniformly even.  By keeping air mixed, temperature differences, especially near the walls and floor, are greatly reduced and the birds spread out, better utilizing all of the floor space. 

When used with other ventilation systems, AGRIFANS help eliminate cold drafts by blending the cold fresh air from the inlets or curtains with the warm ceiling air before moving it down to the floor.  This way the incoming fresh air doesn't drop to the floor, chilling the birds and creating wet spots.  In fact, this mixed warmer air takes up moisture and improves the air quality as well as keeping the litter drier.  This continual circulation from AGRIFANS also helps eliminate temperature swings that result from forced air heaters and interval timers.  The increased comfort promotes more profitable production and better health.

COOLING - In recent years the cooling effect of  AGRIFANS on bird performance has become more important because bird densities have increased and houses are larger.  Even with modern ventilation systems, during hot weather birds that are crowded or in stagnant areas of the barn can become heat stressed.  This results in losses in production efficiency and profits and eventual increase in mortality.

One of the most effective ways to reduce birds' internal body temperature is to provide downward air movement between them and around their heads and bodies, especially featherless areas.  This helps carry heat away and make them feel cooler.  In air movement at a velocity of 350 feet per minute, an 85 degree temperature will feel like 70 degrees to a bird.  However, whether natural or artificial, ventilation must be at bird level to do this and it must reach every bird in the house.

AGRIFANS work well with ventilation systems for cooling.  With negative pressure they help the air entering the house maintain its velocity, directing it downward toward the birds to cool more effectively.  Even with tunnel ventilation there are days during the summer when temperatures are less than 85 degrees and adding the vertical, turbulent  air flow from AGRIFANS would not only be effective, but would save considerable energy over running only the ventilation fans.  For air circulation an AGRIFAN system has a real advantage over 1/2 hp axial-type fans.   AGRIFANS blow the cooling air down to and between the birds where it is needed most to remove heat.  They can run on variable speeds and interval timers to adjust air movement, and they use much less electricity, only .7 amps, even when run continuously.   

AIR CIRCULATION - Continual vertical air flow from AGRIFANS promotes uniformly even house temperatures, drier litter and house conditions, reduced condensation and substantial energy savings.

Good air circulation is not always attained with horizontal blowing ventilation fans run on timers.  This lateral air movement is not uniform or at bird level and some areas of the building, such as the corners, don't have adequate air movement.  These conditions will cause the birds to crowd in certain areas to get warm or cool.  In summer, birds that can't get to the cooler areas will reduce feed intake and can become heat stressed and die.  In winter birds that can't get warm enough will have poor feed conversion and reduced production performance.

Using only axial-type fans in winter, the rising heat may not make it all the way to the floor in some areas and the incoming colder air may drop directly to the floor.   Heat stratification may cause the thermostat, 3 feet off the floor, to read one number while the floor may actually be as much as ten degrees cooler.  Also, these fans are run on timers so there are undesirable fluctuations in temperatures and other house conditions.

AGRIFANS provide the benefits of effective vertical air circulation to ventilating systems.  During brooding, they break up heat stratification more effectively than axial-type fans on timers which may turn off before destratification is even achieved.  In cold weather the vertical air circulation from AGRIFANS, both in up or down blowing modes, re-uses the heat continuously down at floor level, cutting fuel costs.

In winter, for older birds, house temperatures are kept lower.  There is less temperature difference between the floor and ceiling, but ventilation rates are higher because the larger birds put out more moisture.  AGRIFAN's air circulation warms  the incoming fresh air with the ceiling air, enabling it to absorb moisture from the house and litter as it travels up through the fans, down the walls and across the floor.  This moisture is removed through the exhaust fans.  This added moisture control can reduce the amount of ventilation run time needed as well as the amount of ammonia produced .

By keeping house temperatures more evenly warm, AGRIFANS also help keep the floor temperature at the thermostat setting.  This  reduces cold spots and drafts and helps the older and larger birds to spread out and use the whole floor

In summer the vertical, turbulent air flow cools between the birds and eliminates stagnant corners.  In all seasons house conditions are healthier because  AGRIFANS' continual air circulation reduces both condensation and ammonia levels and evaporates moisture from litter and building and equipment surfaces.

DRYING LITTER - During growout all of a birds life is spent on the litter in its house.  The only other environment it comes in contact with is the air right above it and the condition of the litter has a huge effect on the quality of that air.  AGRIFANS improve the quality of the litter.

Neither cold air  or non-moving, warm moist air near the floor can hold or remove very much moisture.   AGRIFAN'S continual mixing and vertical flow of warm air across the floor promotes drying and moisture removal .  For every 20 degree rise in temperature, especially near the floor, the moisture holding capacity of this air doubles.  It also helps to prevent caking of the litter in winter.  

The continual circulation of air by AGRIFANS destratify the heat this way in the whole house.  This air movement then moves the moisture-laden floor air up to be mixed and exhausted by the ventilating fans.  Dryer litter decreases ammonia, improves respiratory health and  helps control pathogen levels.  Dryer litter also results in better grades, with reduced breast blister, cleaner birds and better legs.

In summer, AGRIFANS' direct vertical air flow  dries litter by evaporation.  Ventilating fans alone, which blow air horizontally, do little to dry litter in either season.

BETWEEN GROWOUTS - Before a new flock is brought in AGRIFANS work two ways.  On existing litter, AGRIFANS run at high speed will dry out the litter faster.  Then, before the new birds are brought in, AGRIFANS push the heat down to the floor to thoroughly warm the litter.  This direct recycling of heat also saves considerable energy.

 

 See test results on ceiling fans. Click here for Poultry Research

 

For more information, or for the distributor nearest you, call :  

 

1-800-236-7080

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