Thermal analysis of an ecological, one-family building with two types of solar air collector

The main purpose of passive or active solar system applications is not only high efficient collecting and storing of solar energy but effective distribution the heat around the building spaces as well. The main goal of this work is to analyse and compare two types of solar air collector integrated in an ecological, low-energy, one family building. The first one, is a large volume sunspace located on the south-west of the building and the second, is a small volume and flat solar panel on the roof. Both collectors are connected with particular rooms by a ventilation system. The components of this system include air flow gaps for natural ventilation and various devices for mechanical ventilation. Some components are controlled on the basis of the zone¿s air temperature. Numerical analyses have been conducted for selected two-week periods using hourly Polish weather data. The results show that during the selected, coldest winter period, the air temperature inside the collectors does not exceed 20°C and there is no additional heat flow from the collectors to the rooms. Effective heat gains appear just from March to the end of the heating period. During this period, an additional fan is on and excess energy is transferred to the rooms not only by conduction but by convection as well. The presented results illustrate the differences in heating energy demand and thermal performance of the building. The utilisation of solar energy can reduce heating energy demand and decrease the number of heating hours. Finally the efficiency coefficient of the system was estimated as a function between solar energy gains and heating energy requirements.