How to Cut Hot Weather's Toll
Bill Raufer
| Monday, July 09, 2001
Giving your facilities a comprehensive cooling inspection can be one of your best time investments. That is, provided you follow up with needed repairs and maintenance.
You may be surprised to find "profit leaks" in each building because of the many factors that influence your animals' comfort. Remeber, an uncomfortable animal is an inefficient animal. This year in particular, wasted power can push your bills higher than necessary.
This article presents useful tips on what to look for and what to do about problems in your facilities. Steve Matthis, as an adult-education instructor at Sampson County Community College in North Carolina, has worked with hundreds of pork producers in the hot, humid southeast.
Over the past 20 years, he has amassed trnemendous experience on repairing and maintaining hog buildings and equipment of all kinds.
"As a farmer," Matthis says, "I know how easy it is to overlook a problem with a piece of equipment as long as it is still running. But, preventative maintenance is one of the best investments a pork producer can make."
Here are his observations and recommendations:
Fans: They have a big job to do, day after day in hot weather. Maintenance determines a fan's performance and operating cost.
- Dusty fan blades can reduce an exhaust fan's output by 20 percent or more.
- An inefficient fan can easily use twice as many kilowatt hours of electricity to move the same volume of air as an efficient fan.
Fan belts: These are the most common cause of lost power, and drive alignment determines belt life. "V-belt wear is a serious problem that is often overlooked," says Matthis.
The sides of the belt wear due to friction and the belt becomes thinner. It rides lower in the pulley, causing the fan to spin slower and move less air. A badly worn belt on a 48-inch fan that rides into the center of the pulley can reduce fan speed by as much as 50 rpms. This has been shown to reduce air movement by 20 percent.
The belt must be aligned properly to wear evenly and not lose speed due to excessive friction. With a new belt, you should be able to see it over the sides of the pulley. When a belt is allowed to become loose and slip, the result often is premature belt failure – and no one can predict when this may happen.
Check belt tension frequently to help ward off a breakdown during a hot spell. Replace a belt when signs of wear or stretching appear.
Fan motor: It needs to be kept reasonably clean to dissipate heat and run efficiently. Remove dust at least every 30 days, depending on dustiness of the motor's location.
Fan blades: Dirty ones can reduce air-moving capacity by 20 percent to 30 percent. An extreme spike in temperature coupled with reduced fan performance can seriously stress animals. This can be particularly costly with nursing sows because it could reduce milk flow; in extreme conditions, a gestating gilt or sow could abort.
It's important to keep dust and dirt from accumulating on fans and fan guards. You should clean fans after every group of pigs. In farrowing rooms, nurseries and gestation barns, clean fans as needed. Use a stiff brush, small blower or vacuum cleaner. If you use a pressure washer, be sure to cover motors and electrical controls.
Fan shutters: Dirty ones can reduce air flow as much as 40 percent, so clean louvers at least once a month with a brush, vaccum or small blower. Under especially dusty conditions, a house will need cleaning more often.
After removing dust, wash with a water/detergent solution. When dry, lubricate all pivot points with fine-grade machine oil.
Circulating fans: In an open-sided or enclosed, tunnel-ventilated building, don't overlook fans that move air within the animal area. Remove dust and dirt with a brush or broom.
Sidewall curtains: Just as it is important for curtains to fit tightly in winter, so is the case in summer. Air losses due to a torn or sagging curtain can destroy exhaust fans' effectiveness. Tighten any curtain straps that have become loose.
Check each curtain from one end of the house to make sure it is straight and level.
Cables/pulleys: Ones that raise and lower side-wall curtains must be properly aligned. A cable needs to feed straight into the pulley's groove to avoid excessive wear and inefficient operation.
Misaligned cables can wear quickly and cause unexpected failure of vents or curtains.
Pulley diameter: Cable wires bending around a small pulley can cause excess breakage. The outside strands start stretching and fraying first. The larger the pulley's diameter, the longer the cable will last.
"With a small-diameter pulley," Matthis notes, "the cable tends to slide over the surface, causing uneven wear and premature breakage."
Electric motors: Dust and dirt on an electric motor can dramatically reduce its ability to dissipate heat, which may cause premature motor burnout. At least monthly, use a brush, small vacuum cleaner or compressed air to remove dust and dirt.
Thermostats: Regularly dust and check calibration. An improperly calibrated one that turns a fan on prematurely can waste a great deal of energy. If the thermostat reads too low, the animals in the building may experience heat stress.
Static pressure: It's important to calibrate your photohelic that controls curtains. Make sure the static pressure is set to meet the animals' requirements within the building. A hand-held checking device can be purchased or made from parts of a working photohelic.
Pressure washing: When cleaning a building, cover all electric motors and controls with plastic or casings to prevent water damage. Keep in mind that these coverings are water-repellent and not waterproof. "If you spray directly with 2,500 psi," says Matthis, "the covers will leak, and the motor and controls will be damaged. Always remember that many automated, computerized controls cost $500 and up."
Unplanned inlets: Cracks or holes in the ceiling or side-walls of a tunnel-ventilated building can greatly increase electricity use and cost. Ill-fitting curtains also are unplanned inlets. To maintain proper static pressure, you must increase the building's ventilation rate (cubic feet per minute). Increasing the cfm raises electricity cost.
Be sure to check door sweeps and thresholds for air leaks. Worn, damaged rubber can defeat other efforts to prevent leakage.
Expanding foam that comes in a pressurized container is a good choice to fill small cracks in walls and ceilings.
Tools and equipment: For effective preventative maintenance, you need to have the right tools and equipment. Dedicating a person in your operation to the task can make most needed repairs promptly without having to hire outside help. Doing your own "in-house" repairs will save time and money.
To-do checklist: "It's impossible to remember every preventative step that should be taken. Developing and using a checklist for each building avoids overlooking anything," says Matthis.
In his hog building and equipment classes at the college, Matthis requires each student to make a checklist specifically for a building in which he or she works. "This is a great exercise and impresses on the individual what a large number of things need to be watched and done routinely."
Team effort: With everyone in your operation aware of the many factors influencing summer cooling – and encouraged to fix or report potential problems – you should be able to head off serious, costly problems with preventative maintenance. The rewards will be improvements in: (1) summer working conditions for employees; (2) animal performance, (3) energy costs, and (4) overall cost of production.
Always be sure to disconnect electricity at the power source – master switch, circuit breaker or fuse box before working on an electric motor or any electrically powered equipment.
