Protecting your growing business with insurance is important, but there are other ways to make sure you get the most out of your investment. Midwest Greenhouse Supply suggests choosing a greenhouse covering can be the least expensive and most important decision a grower can make. Still, it’s surprising to see how many growers are not taking advantage of infrared (IR) plastic film on their greenhouses. The low cost of purchasing IR film compared to the cost of fuel can result in growers receiving a payback of less than one week – or about a 2,500 percent return – on investment. This, added to the enhanced plant response, lets growers optimize their only FREE resource – the sun.
How did IR Film start? In 1972, film producers in Spain put diffusing particles in polyethylene films to diffuse light with the hope that the even distribution of light would produce a faster, fuller and more even crop growth. The results showed that not only did that happen, but also helped unheated greenhouses stay warmer into the evening. It took 12 years before the technology was tested/researched by Rutgers University in 1984. The experiments validated plant response and demonstrated a savings of up to 35 percent could be achieved with IR versus conventional/clear film. The research also concluded the savings might average out to 15-20 percent over a heating season.
The Advantages of IR Film. During the day, energy from the sun enters through greenhouse film as short-wave radiation and is quickly converted to heat when the waves strike plants, floors or other objects like benches. In these conditions, the use of an IR film diffuses light and spreads the light evenly throughout the greenhouse. This diffusion reduces shadowing, allows more light to reach lower into the plant canopy and provides less stress to the plant by averaging out leaf temperatures. These combined benefits may result in an earlier crop. The reverse of this happens in the evening when the heat provided by the heating system is lost by conduction, convection and radiation through the glazing and infiltration of cold outside air through cracks and openings. The IR films ability to slow re-radiation can result in minimizing the total heat loss to usually about 12 percent.
ROI Results/Example. Manufacturer techniques have continued to improve resulting in the differential cost of IR (compared to traditional film) of 2-4 cents per square foot. The following example demonstrates the potential ROI that can be achieved through the use of IR film.
- 30 X 86 foot greenhouse (2,880)
- House located in Ohio and operated at 60 degrees Fahrenheit at night
- No 2 Fuel Oil is purchased at $2.05/gallon
- Annual fuel usage in conventional/clear covered greenhouse is 1.25/sq ft
- Annual heating cost of 2,880 greenhouse would be $7,380
- Life of both conventional/clear and IR films is 4 years
- Square foot cost of IR film is $.03 higher than conventional/clear film
- Increased cost on 2,880 square feet greenhouse would be $86 or $21/year
- Fuel savings attributed to IR films is 12 percent (conservative to Rutgers findings)
Based on the above assumptions, a 12% savings in fuel costs ($885) compared to the increase annual cost of IR film ($21) results in a return on investment in less than 12 days.
As noted, there is nothing in a greenhouse that can make more money than optimizing the free resources of the sun. Please contact Midwest Greenhouse Supply (440-310-7051, firstname.lastname@example.org) for a free, no obligation customized quote and/or ROI analysis on your polyethylene film or other greenhouse structural needs.
Hortica has partnered with Midwest Greenhouse Supply to help you reduce your poly costs up to 30% through our Customized Poly Program. This program is exclusively available to Hortica members.