Issue 6/2019

This paper deals with analysis and modelling of thermal dynamic processes of a panel radiator. The analysis is based on observing the temperature field on the frontal surface of the radiator by a thermal infrared camera. Two different simulation models in Matlab Simulink are presented here. Both are made for the specific panel radiator (a classic type with one panel, 0.5 m height and 1 m long with a single side connection from the top to the bottom). The dynamic behaviour is usually determined by (expensive) measurements, so the main goal is to create such a model that will be simply able to simulate the dynamic behaviour as real as possible for certain similar types of radiators, with minimum input values.

The paper deals with the summary and comparison of surface temperature results from mathematical simulations for different turning and geometry of distance rings based on numerical values of the temperature field on the panel radiator front plate. The changes in flow through individual channels are also compared with respect to the distance rings and the influence of velocity field on temperature field is commented. The results of the temperature and velocity fields for the two-way connection of the radiator for the given cases are given below.

The technology of exhaust air heat pump (EAHP) units and a brief classification of the products available on the market are presented in this paper. The performance of a compact EAHP unit providing exhaust air ventilation in a single-family house has been investigated. Due to the limited data provided by the manufacturers or by the 3rd party test reports, the laboratory testing of the EAHP unit has been performed. The data obtained from the test have been applied in the energy balance of the unit. A single-family house with a total heat loss of 5 kW was considered and the seasonal performance factor (SPF) achieved 2.5 for the given system with the compact EAHP.

The simulation model of an energy system consisting of a ground-source heat pump combined with PV and thermal storage tanks for a single-family house was developed. The PV system is connected to the heat pump for the domestic hot water preparation and space heating. The energy system allows one to maximise the usage of the PV power by means of overcharging the volume of the storage tanks by the heat pump with the use of an adaptive control. Furthermore, a parametric analysis incorporating the different PV system power installed was carried out. With respect to the total electrical energy consumption of the heat pump, the annual grid consumption may be reduced up to 40 %.

The paper deals with the issues of the Smart Readiness Indicator (SRI), which describes buildings in terms of their intelligent systems. In first part, the principles of SRI and the processes of a building’s assessment are explained. The second part contains a case study of four buildings in the Czech Republic with different technical systems and the Smart Readiness Indicator is calculated for them.

The issue of energy consumption is becoming the main topic in many fields. Buildings that consume over 40 % of all the primary energy in developed countries, together with a significant contribution of CO2 emissions [1], currently receive a considerable amount of attention. The paper deals with the issue of energy consumption of HVAC systems of buildings during their real operation and with process of their commissioning. The commissioning is solved both in general terms and as a mean of achieving the correct and energy efficient operation of buildings. Special attention is paid to the situa tion in the Czech Republic.