ASABE Technical Library - Abstract

Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, view access and subscription options

Surface temperatures on different roof designs in warm and clear weather

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org

Citation:  2026 ASABE Annual International Meeting  2600696.(doi:10.13031/aim.202600696)
Authors:   Bjarne Bjerg, Li Rong, Peter Kai
Keywords:   Albedo, cattle, ceiling, construction, cows, design, material, roof, solar radiation.

Abstract. Global warming and increased concern for animal welfare make it urgent to develop housing systems that can reduce the heat load that production animals experience during warm periods. Cattle are often housed in buildings with an uninsulated roof, where solar heating on the outside of the roof during warm periods can cause a large heat conduction through the roof and a resulting high ceiling temperature. Eternit (fiber-cement) is widely used as a roofing material throughout most of the world. In Denmark it has been the dominant roofing material for all types of agricultural construction, both before and after the harmful asbestos content was phased out in the 1980s. The aim of this study was to compare the ceiling temperature in sunny weather for different roof designs relevant in relation to Danish cattle housing. Totally eight measurements were conducted around noon on three clear days from June 30 to July 3, 2025.

As average, the underside surface temperature for the six studied roof design was between 0.7 and 15.6 ˚C higher than the surrounding air. The lowest temperature was for a partially transparent PVC sheet and the highest was for an approximately 50-year-old eternit roof. Heat balances calculations for the upper and underside surfaces of the investigated roof designs resulted in lower temperatures on the underside than in the measurements (except for eternit painted with high reflective paint), but it also showed that these calculations was quite sensitive with respect to the assumptions used regarding albedo, sky temperature and the convective heat transfer coefficient.

(Download PDF)    (Export to EndNotes)