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The results of experimental investigation of determining the time of temperature drop in domestic hot water circuit were presented in this paper on the example of single-family house. The test were carried out on vertical sections of installations made of PE-X/Al/PE pipes (cross-linked polyethylene and aluminum) with and without insulation. The temperature drop process was investigated in temperature range typical for domestic hot water installation from 55ºC to 40ºC. On the basis of the obtained results with appropriate adjustment of the working time of circulation pump, energy savings of 90% were achieved.

The air relative humidity in closed spaces of indoor swimming pools influences significantly on users thermal comfort and the stability of the building structure, so its preservation on suitable level is very important. For this purpose, buildings are equipped with HVAC systems which provide adequate level of humidity. The selection of devices and their technical parameters is made using the mathematical models of water evaporation rate in the unoccupied and occupied indoor swimming pool. In the literature, there are many papers describing this phenomena but the results differ from each other. The aim of the study was the experimental verification of published models of evaporation rate in the pool. The tests carried out on a laboratory scale, using model of indoor swimming pool, measuring 99cm/68cm/22cm. The model was equipped with water spray installation with six nozzles to simulate conditions during the use of the swimming pool. The measurements were made for conditions of sports pools (water temperature 24°C) and recreational swimming pool (water temperature 34°C). According to the recommendations the air temperature was about 2°C higher than water temperature, and the relative humidity ranged from 40% to 55%. Models Shah and Biasin & Krumm were characterized by the best fit to the results of measurements on a laboratory scale.