Experimental transmittance of polyethylene films in the solar and infrared wavelengths
Authors: Balocco C., Mercatelli L., Azzali N., Meucci M., Grazzini G.
Autors Affiliation: Dipartimento di Ingegneria Industriale, DIEF, Università degli Studi di Firenze, via S. Marta 3, Firenze, Italy; Istituto Nazionale di Ottica, INO-CNR, Largo Enrico Fermi 6, 50100 Firenze, Italy
Abstract: The growing use of plastic film coverings in agriculture is due to the possibility of increasing the air temperature around the plants, reducing radiative and convective energy losses, protecting fruit trees from adverse weather conditions, reducing fungal diseases, assuring less reliance on herbicides and pesticides, better protection of food products and more efficient water conservation. Low-density polyethylene (LD PE) is one of the most widely used plastic films for greenhouse coverings, low and medium tunnels and soil mulching. In this paper, we present radiometric properties of a new and old (used for more than five years) LD-PE film, experimentally investigated using different methodological approaches for different wavelength bands, especially at medium IR. Experimental measurements in the IR wavelength spectrum, included the Near (0.78–3 μm), i.e. N-IR-A (0.78–1.4 μm) and N-IR-B (1.4–3 μm) and Medium (3–50 μm) in accordance with ISO 20473 (E) 2007 were carried out. Experimental results obtained are in agreement with those in the literature and show that the aging effects are minimal in the plastic film used for five years. This finding is crucial for greenhouse design. Referring to practical applications, energy balance of an ordinary agricultural greenhouse was also evaluated. The authors believe that this research results on all the optical properties in a wide spectral range of LD-PE will be useful not only in agriculture, but also for any other solar engineering application.
Journal/Review: SOLAR ENERGY
Volume: 165 Pages from: 199 to: 205
KeyWords: Agriculture; Chemical contamination; Energy dissipation; Energy efficiency; Food products; Greenhouse effect; Greenhouses; Low density polyethylenes; Optical properties; Orchards; Plastic films; Polyethylenes; Radiometry; Water conservation, Agricultural greenhouse; Convective energy; Energy performance; Infrared wavelengths; Methodological approach; Polyethylene film; Radiometric measurements; Wide spectral range, Plastic products, air temperature; Climate conditions; Experimental study; Greenhouse effect; Measurement method; Performance assessment; Polymer; WavelengthDOI: 10.1016/j.solener.2018.03.011Citations: 8data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here