I just looked at my outdoor thermometer and it was registering -8F (-22C). This means supplemental heaters are operating in many swine facilities in the upper Midwest. I can also safely assume that many of these heaters are consuming more fuel (propane or natural gas) than necessary.
In February of 2016, Iowa State University Ag Engineers released a publication detailing ‘normal’ propane and electric usage targets for upper Midwest production facilities (PM 3063E). The values in this publication are the result of tracking consumption on 30 farms in Iowa, Minnesota and Missouri for 2 years and agree closely with the estimates I had been using for my clients.
On Friday morning I was at a curtain barn wean-finish site in southern Iowa that was averaging 8 gallon of propane per pig space per year. This compares with the ISU target of 3 gal/space/yr for curtain barn wean-finish facilities. With some simple changes in controller settings we were able to immediately reduce furnace operation and have the brooders operate at low flame and note an improvement in pig comfort, all without changing the controller set point.
What are the most common causes of high fuel usage in swine production units? My list is rather short but the impact of mistakes is huge when it comes to fuel usage:
1) Improper controller settings is #1 on my list. In this category are the on/off settings for heaters relative to set point, minimum fan speed settings and motor curves.
2) Equipment sizing. This is quite common in farrowing rooms where the builder only installed 3 fans in a farrowing room and the minimum fan is too large in order to get the total cfm for summer ventilation adequate. A 14” fan operating at 100% is generally sufficient for minimum ventilation for 100 farrowing crates. I often see a 16” or 18” fan as the minimum fan in a 30 to 48 crate room. With the wrong motor curve in the controller and wrong minimum speed, it not uncommon to have these rooms with minimum ventilation rates of 60-80 cfm/crate when the MWPS recommended rate for winter moisture control is 20 cfm/crate.
3) Emergency override thermostats. I often see these thermostats operating heating equipment in grow-finish sites when they are not reset as the set point in the controller is lowered.