Translucent cover is one the main design features of solar energy equipment like solar collector. Its material and layers number influence on overall translucency of the cover and, as a result, on efficiency of the equipment. Formwork, equipped by translucent cover, can be considered as solar energy equipment like solar collector due to similar thermal-physical processes, taking place in it. Such equipment can be used during manufacturing of prefabricated concrete components to speed up the curing process by heating the structures using solar energy. The aim of our research work is determination of optimal layers' number of translucent cover. The research was made in various climatic conditions. The obtained results testify to certain influence of translucent cover design on efficiency of solar energy equipment. However, this influence depends on climatic conditions. © Published under licence by IOP Publishing Ltd.