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

• STEP TWO :  OPERATING YOUR SYSTEM

• STEP THREE :  ACHIEVING YOUR SPECIFIC OBJECTIVES

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