National Poultry Technology Center
AUBURN, Ala. — Fall is here and winter won’t be far behind. This time of year every poultry grower begins to think about keeping birds over the winter. As this time approaches, fuel costs are always at the forefront of growers concerns. Many are searching for the single thing we can do to minimize fuel cost.
Sadly, there is no “silver bullet.” The answer is most often a multi-point approach. In hard times, often doing the best with the resources we have at hand is our best management philosophy. In today’s energy economy when you wisely spend money on energy reduction practices it usually is a very good investment and pays back in less than two years.
There are three relatively inexpensive fuel-saving steps we tell folks to look at when they ask where they should focus their time and resources to reduce energy consumption and keep bird performance up.
These steps are not new and not particularly high-tech. They are the basics. Remember that doing a good job in keeping costs down in poultry production is similar doing a good job coaching a football team. Successful programs usually start with a good understanding and application of the basic principles.
Here is our list of basic steps you need to take (if you have not already) to tackle your runaway energy costs.
Step 1: Tighten the house — Stop air leaks
Air that bypasses the ventilation air inlets and comes in through cracks, holes, etc. spoils environmental control of any poultry house. A house that cannot achieve a 0.12 to 0.15 inches of water column during a house tightness test must burn unnecessary energy and fuel to maintain the target environment for the bird.
Common voids that allow air infiltration into the building envelope are: loose sidewalls; loose tunnel inlet curtains; voids between carpenter joints; voids between lumber walls and concrete footings; cracks around end wall doors; cracks around access doors; sidewall or ceiling vent inlets that hang loose; damaged fan shutters; holes rusted in outside wall metal; and holes in the dropped ceiling material.
Maintaining a tight building envelope around the birds is of utmost importance. Making serious adjustments tightening the building envelope of a house that tests below 0.09 inches of water column can save 25 percent on heating fuel costs.
Step 2: Stir the air
There have been so many good newsletters written about using stir fans to cut fuel costs in heated poultry buildings that it is hard to understand why folks don’t seem to get the message and so many houses in the poultry belt don’t have them. Stir fans can be used on new or old poultry farms to produce a sizeable fuel and production benefit for the grower.
In non-engineering terms here are the basic facts about stir fans: Without stirring, air stratifies; that means hot air rises and cold air falls, so most of the warm air will concentrate in the top center of the house.
We are basically heating the poultry house from the top down. Good ventilation management in a tight house, with vent doors throwing the outside cool air to the top of the house certainly helps reduce stratification. However, especially in older houses and even in new houses there is more stratification and need for stirring air than the vents can accomplish. This is especially true during minimum ventilation when air flow is at the lowest. Aggressive stirring of the air reduces stratification, promotes uniformity, makes for a drier house and causes the brooders and heating devices to run less.
How much do stirring fans help? Study after study after study shows stir fans in newer houses can save about 10 percent on fuel in newer houses. Older houses can see as much as 25 percent reduction in fuel costs. The taller the house the more benefit to using stir fans. If you have a house with no air inlets (curtain crack ventilation) or very poor air inlet air profiles, the stir fan is the best single band-aid you can place on your house.
We like to see folks using 20-inch to 24-inch basket fans in smooth ceiling houses. These fans should be slightly tilted up to wash the heat off the ceiling. There are many different ways to run stir fans. Some would recommend them be run continuously, others would alternate them with the opening and closing of the vent doors. There may not be one correct answer to that question but it should be decided on a house to house and even flock to flock depending on the weather. In high ceiling houses the paddle fan is the stirring device of choice because of the baffles that are normally installed to help with tunnel ventilation.
Step 3: Wall up and insulate
People that are serious about saving money on fuel convert their buildings to solid sidewall. Using solid walled buildings drastically cuts down on the amount of heat lost through conduction. Insulation is installed in or on the surfaces of the building to prevent the transfer of energy through the surfaces of the building.
There are several methods that can be used to achieve a true solid sidewall that is air-tight and well insulated. Insulation value is measured in (conductive) R-values. The higher the R-value the better the insulation is at preventing heat transfer through the material. Typical (conductive) R-values of materials in poultry buildings are as follows: Curtain material = R-1; 2-inch dimensional lumber = R-2.5; 1-inch board insulation = R-5; 3.5-inch fiberglass batt = R-11; 6-inch blown cellulose = R-19; 1-inch spray foam = R-5; and bubble wrap = R-1. The first few points in R-value will yield the quickest paybacks.
A good rule of thumb is that when you increase the R-value of a material from R-1 to R-2.0 you essentially cut the heat lost through that material by 50 percent. When you go from R-1 to R-8 you cut the heat lost by 85 percent. New construction specifications for poultry buildings commonly call for R-11 or R-19 sidewalls and R-19 to R-21 ceiling insulation in most poultry growing areas.
A grower that does a good job tightening and insulating the entire building envelope and goes from a loose, R-1 curtain-sided house to a well-tightened R-11 sidewall and R-19 ceiling could see a 50 percent reduction in fuel costs.
We are still a little removed from cold weather in much of the poultry growing regions of the U.S. So there is still time to take the steps needed to minimize fuel costs this winter.
There are many relevant newsletters addressing this and many other topics important to commercial poultry growers available free of charge at www.poultryhouse.com. Please take the time to visit us there. The National Poultry Technology Center at Auburn University wish all growers the very best of luck this winter!
More information from the National Poultry Technology Center (NPTC) at Auburn University can be obtained at www.poultryhouse.com.