Farmers who rely on propane to heat livestock facilities can take steps to use the increasingly costly fuel more efficiently – and without making expensive capital investments, a Purdue University specialist says.
The liquid propane, or LP, used for heating many confined livestock barns has been in short supply and high demand amid the frigid Midwestern winter. That has translated to the recent high price of propane.
According to Al Heber, professor of agricultural and biological engineering, the place to start for more efficient use of propane in barns is the thermostat.
"Lowering the temperature set point for heating might be a good first plan of attack because it is quick and effective, if it can be reduced without creating unhealthy conditions for the animals or birds," he said. "Livestock and poultry producers need to judge animal comfort as they lower the temperature."
One way to gauge animal comfort in hogs, for example, is to observe whether they are huddling in groups for warmth. Heber said this behavior means the animals are too cold.
Another way to be more efficient with the heating thermostat is to understand how animals tolerate temperature. An example is nursery hogs, which can tolerate a 10-degree drop in housing temperature at night.
Producers also need to monitor the heating and ventilation control systems in their facilities to make sure the winter fans aren't competing with the heaters. Ventilation fans with rates greater than what is required for humidity control function as a cooling system. If the ventilation system senses the air temperature getting too warm, it will draw in more cold air. If the heating system senses air temperatures getting too cold, however, it will continue putting out heat.
When the systems compete, they waste propane. Heber said care must be taken to keep this from happening.
"A failure to interlock the heater and the second stage of ventilation can cause a tremendous waste of propane," he said. "A quick audit of the barns should be conducted to make sure this isn't happening."
In this same vein, Heber said producers should assess whether the minimum winter airflow rate in the barn is much greater than the recommended minimum ventilation rate and can be safely decreased. The minimum ventilation rate refers to the base rate at which the system adequately controls humidity and ammonia at safe levels.
"Over-ventilating the building in cold weather will increase propane use to unnecessary levels," he said. "Over-ventilating by 10 percent can increase annual LP consumption by 27 percent, according to research at Iowa State University."
Other ways for producers to use propane more efficiently involve building maintenance. Ventilation air inlets need to be properly maintained, and air leaks should be eliminated.
Producers can assess the efficiency of their facilities by having an on-farm energy audit. During an energy audit, professionals come out to the farm and look at where facility improvements could be made. They outline savings-to-investment ratios for implementing those improvements, whether that's as simple as caulking areas of air leaks or as investment-heavy as adding heat exchangers.
Martin said farmers could apply for grants to offset the costs of the audits and farm energy efficiency improvements. The U.S. Department of Agriculture Rural Development offers the Rural Energy for America Program, or REAP, to provide assistance with energy efficiency improvement projects. The USDA Natural Resources Conservation Service offers Environmental Quality Incentives Programs, and many utility companies also offer rebate incentives.
Livestock producers with questions about environmental control, energy efficiency and air quality in their facilities can contact Heber at 765-494-1214 or firstname.lastname@example.org.