The aim of investigations was to compare different absorber material efficiency to examine collector tracking the Sun and stationary collector efficiency as well as the efficiency of insulated and non-insulated collectors. The 0.1x0.5x1.0 meter long experimental solar collectors were constructed for investigations and different types of absorber materials were made. The manifold length, the Sun radiation effect on the degree of air heating was analyzed. ASHARE used standard 93-2003 is determined for insulated and non-insulated solar collectors and absorber effectiveness. We determined the influence of the Sun radiation on the air heating degree for those types of absorbers. The experimental data were measured and recorded in the electronic equipment REG (electronic metering and recording equipment of temperature, radiation and lighting). The collector covered material was a polystyrol plate and different absorbers. We compared insulated and non-insulated collectors to prove that the insulated collector is more effective. The insulated collector was made of the collector surfaces faced with cellular plastic two cm plates. Our task was to calculate the air heating solar collector efficiency. The collector tracking the Sun is approximately 30% more efficient than the same type of stationary collectors in operation time for 6 hours. Insulation increases solar panel efficiency especially in windy weather. The insulated collector demonstrates almost two times higher efficiency than the non-insulated collectors (up to 93%) with absorbent material steel tinplate on top.

In order to get maximum economic effect, when setting a solar collector in a peasant yard, it is important to choose the correct place. The yield of obtained heat energy will be at its maximum, if the temperature of surrounding air and solar radiation are higher by the relative humidity of the air - lower. To define these parameters, a special device 'Meteorological Device' (MD-4) was developed. The device was supplied with a mechanism which tracks the sun all day round. So the direct solar radiation on the surface perpendicular to the sun beams was measured. The second measuring of the solar radiation was made in relation to the surface, which was perpendicular to the sun beams only at the middle of a day time. For the measuring of the air temperature and relative humidity, corresponding sensors were used. In every 15 minutes the data of these four meteorological parameters were automatically measured and the results were saved into a logger - the device for data accumulation. After a certain period of time the information was brought into the memory of a computer and analysed.

Nowadays, different sun protective creams are available in the market, but most of them contain harmful synthetic chemicals and minerals which can induce skin allergies and premature ageing. Usage of sunscreens and photoprotectors of natural origin and natural antioxidants can reduce skin damage caused by excessive sun exposure. The effectiveness of the use of β-carotene — vitamin’s A precursor against excessive irradiation caused by oxidative stress cell damages has been proven of its very good antioxidative properties and leading to sooner regeneration of the skin after several environmental damages. Carotenoids and high value oil can be extracted from pumpkin (Cucurbitta spp.) by-products — peel and seeds with SC CO2. The objective of this study was to incorporate pumpkin seed oil (PSO) and carotenoid extract (CE) from pumpkin by-products in to facial creams for UV protection. Two types of creams with PSO and CE were prepared emulsion o/w and w/o. A cream without extracts and natural ingredients was used as control sample. The sun protection factor values in vitro (SPF = 0.92 to 1.18), total content of carotenoids (TCC = 1.08–17.95 µg mLE−1), β-carotene content (0.64–0.72 µg mLE−1), total phenolic content (TPC = 62.64–95.82 mg GAE gE−1), antiradical scavenging activity (11.26–43.66 %) and rheological behaviour of facial creams were determined. Although creams with CE and PSO show comparatively low SPF values, ß-carotene and phenolic compounds found in samples demonstrated very high antioxidant abilities valuable for skin protection.