From insulation to ventilation management to lighting, you can find ways to reduce energy costs and still keep pigs comfortable.
It’s no secret that energy costs have climbed in the last year. Here’s a quick look: In 2005, propane prices averaged $1.33 per gallon — a doubling in price since 1995. Gasoline prices averaged $2.15 a gallon in 2005, up 40 cents from 2004. Electricity prices also have climbed.
Such price increases cut into your operation’s profitability, often subtly over time, which can leave them unchecked. The sudden hit of a high energy bill often leads to questionable choices. “I emphasize to producers, when they get a high propane bill, don’t turn the ventilation down,” says Jay Harmon, agricultural engineer,
“Proper building maintenance and equipment-control settings are as important as anything,” he notes. “Cracks can develop over time and eventually waste energy, but that’s an operational reality. You need to address areas that provide a good environment for the pigs and minimize energy costs.”
Harmon suggests using the following tips for ways to keep energy bills from eating up your profits.
Perimeter insulation for a building might be the best investment. “It’s something relatively easy to add, it’s low cost and it can provide some energy savings,” says Harmon. “Adding insulation may allow you to operate a room at a cooler air temperature because the pigs aren’t exposed to cold concrete.”
Here’s an example of what you’ll find in an average hog building. Consider a 1,000-head nursery that is 41 feet x 84 feet, having R-11 insulation in the walls and R-30 in the ceilings. With a fan at 2.5 cfm per head, a 76° F average temperature, and propane cost at $1.33 per gallon, your estimated annual propane use is 995 gallons at a cost of $1,324.
Adding perimeter insulation can reduce the heat cost by about $250 a year, says Harmon. This also will raise the temperature of the concrete, possibly letting you operate a nursery at a cooler temperature.
Many nurseries are operated at warmer temperatures than required. Try to reduce drafts and set the temperature where the pigs appear to be comfortable. Proper insulation also will reduce condensation on the walls and floors that usually occurs without adequate insulation levels.
Ventilation and Temperatures
“In a typical swine facility, 80 percent to 90 percent of the heat loss is associated with ventilation,” says Harmon.
Of course, you have to start by selecting the proper ventilation rate for the facility and the group (age and stocking density) of pigs. This will help keep the humidity level at an optimal 50 percent to 60 percent. Drop the humidity too much, and you’re actually over-ventilating. Under ventilate and you’ll end up with high humidity and health problems.
Check to see that gas levels are acceptable. The ammonia level should be 25 parts per million or less; hydrogen sulfide needs to be 5 ppm or less. While this is a health issue for both the pigs and your employees, it also signals acceptable ventilation levels.
“You never want to cheat on ventilation, in an attempt to save money, because it could cost you more in veterinary bills,” says Harmon. High ammonia rates can cause respiratory problems.
Temperature is another guidepost. There is no absolute temperature for any group of pigs, so it’s always wise to watch the animals to determine their comfort level. You can tell a lot by the way the pigs are laying. Certainly, if pigs are huddled together, they are cold; if pigs are sprawled out away from each other, then they are too hot.
While most producers and employees understand this, they often fail to take time to look at the signals that pigs are sending, says Harmon. “It can provide a lot of information at a glance,” he says.
Other things to look for are drafts and cold surfaces. Determine whether there is a way to use zone heat with a radiant heater to create a micro-climate where the pigs feel warmer because they’re exposed to a warm surface. This again, let’s you run the building’s air temperature a bit cooler. It’s less expensive to zone heat than to heat an entire building, notes Harmon.
The building’s curtains are another area that can run up your energy bills. Here are a few things to watch:
Curtain edges should overlap at least three inches, for a tight seal.
Check for curtain leaks and sags. The slightest crack can cause the system to over ventilate the building.
Check end pockets to make sure they are tight.
Look for rodent damage. This is especially critical after the curtain has been down for an extended time, because it will collect moisture and allow mice to find a home.
Check limit switches in the curtain machine to make sure the curtains stop at the proper location, overlapping to prevent leaks at the top.
Heaters, Controllers, Fans
Take time to listen to the cycling intervals of heaters and fans to make sure they’re running properly. Stand in your building and listen to the equipment. Once the heater shuts off, you should not hear the pit fans increase speed. If you hear this, it means they are overshooting the setpoint and exhausting the heat that just filled the building. Increasing the heater offset should solve this problem. Oversized heaters also can be part of the cause.
Avoid small (less than 1° F) temperature differentials in your controllers, so fans increase speed slowly. Two degrees is a good differential.
You also need to select efficient fans. As an example: for a 1,000-head nursery, Harmon points out that the most efficient 24-inch fans tested by BESS labs have an efficiency rating of 19.4 cfm per watt, 7,610 cfm and costs $115 a year to run. The least efficient fan is 8.7 cfm per watt, 6,070 cfm and costs $205 annually to run.
You will need to clean pit fans, including fan transitions (the area where the fan hooks on to the building) to keep them running efficiently. Make sure to tighten all fan belts and check shutters on a regular basis, at least monthly if not weekly.
Lamps and Lighting
Select 175-watt heat lamps for energy savings. In reality, a 250-watt lamp often makes hot spots that chase pigs away from the creep area and increases their risk of being laid on, notes Harmon. Adjust the lamp height to a comfortable level– 18 inches up from the creep area.
A study conducted by Hongwei Xin, an agricultural engineer at Iowa State, comparing energy-efficient, 175-watt lamps versus conventional 250-watt lamps, shows that you can save $36 per unit annually, or $5,500 per 1,000 sows.
According to Xin’s study, the 175-watt lamps had a reduced lamp failure rate—by as much as 50 percent. The study also showed that the piglets had a slightly higher average daily gain, and they maintained a uniform resting pattern under the lamp away from the sow. (You can link to Xin’s study at http://www.abe.iastate.edu/Xin/Xin_Research.html, then click on “Heating Piglets in Farrowing Crates.”)
As for overhead lighting, use compact fluorescent bulbs. Here’s an example of the cost savings: a 75-watt incandescent light bulb will last 750 hours and will initially cost 38 cents. If you operate the light eight hours a day, 365 days a year, it will cost $15.33 annually to run. You’ll need 3.89 bulbs per year at a cost of $1.48, for a total cost of $22.69.
Conversely, an 18-watt compact fluroescent lightbulb has a 10,000-hour life span and initially costs $6.77. Using it eight hours a day, everyday, will cost $3.68 per year. You’ll need 0.29 bulbs a year at a cost of $1.98, for a total cost of $5.66. You save $17 a year or will see a payback in less than five months.
Added up, these tips can save you money by saving energy and keeping your buildings and equipment properly maintained. Take the time to do a routine energy check and you’ll appreciate it next month when your energy bill arrives.
Check Before you Buy
Do your homework before you buy new equipment– even something as small as light bulbs. Use the Internet to find answers and comparison shop, talk to suppliers (ask them the hard questions) and visit with your energy suppliers before purchasing equipment.
Rebates are a common and growing option. Here’s an example:
Check out other rebate prospects, such as those for insulation or general overhead lighting. Alliant Energy also offers a $5-per-lamp rebate for 175-watt or smaller heat lamps, notes Jay Harmon,
Shop around for options in your area that involve benefits from using your backup generator. Check with your local electrical utility on demand-side programs that could get you a cheaper electrical right. It may let you turn off your main power during peak times and use a backup generator instead.