Research on the Indoor Thermal Environment of Attached Sunspace Passive Solar Heating System Based on Zero-State Response Control Strategy

The application of attached sunspace passive solar heating systems (ASPSHS) for farmhouses can improve building performance, reduce heating energy consumption and carbon dioxide emissions. In order to take better use of the attached sunspace to prevent heat transfer or promote natural ventilation, this paper presented a zero-state response control strategy for the opening and closing time of active interior window in the ASPSHS. In order to verify the application of this strategy, an attached sunspace was built in an actual farmhouse. A natural ventilation heat exchange model was built based on the farmhouse with attached sunspace. The proposed zero-state response control strategy was implemented in TRNSYS software. Field measurement in living lab was carried out to inspect the distribution of the thermal environment in the farmhouse with attached sunspace under a zero-state response control strategy in the cold region of northern China. The experimental results show that, even under −5.0–2.5 °C ambient temperature, the application of zero-state response control strategy effectively increases the internal temperature to an average of 25.45 °C higher than the outside, with 23% indoor discernible temperature differential in the sample daytime. The whole-season heating performance was evaluated by simulating the model for the heating season in 2020–2021. The simulation demonstrates that the ASPSHS under zero-state response control strategy can maintain a basic indoor temperature of 14 °C for 1094 h during the heating season, with a daytime heating guarantee rate of 73.33%, thus ensuring higher indoor heating comfort during the day. When compared to a farmhouse with an attached sunspace under the zero-state response control strategy, the energy savings rate can be enhanced by 20.88%, and carbon emissions can be reduced by 51.73%. Overall, the attached sunspace with the zero-state response control strategy can effectively increase the indoor temperature when the solar radiation is intensive and create a suitable thermal environment for the farmhouse in the cold region of northern China.

The Impact of Local Anti-Smog Resolution in Cracow (Poland) on the Concentrations of PM10 and BaP Based on the Results of Measurements of the State Environmental Monitoring

As a result of conducted air quality policy, including recent legal regulations (the local anti-smog resolution), the number of individual solid fuel heating devices in Cracow (Poland) gradually decreased. Reports on air quality in the city indicate that the concentration of pollutants in Cracow’s air shows a downward trend. However, a similar tendency in terms of improving air quality is also observed in the entire voivodeship, where, as a result of analogous although less radical measures, the number of individual solid fuel heating devices is also decreasing. The paper discusses the impact of legal regulations in Cracow on the improvement of air quality in the context of changes taking place in nearby cities. Trends in changes in PM10 and BaP (PM10) concentrations are analyzed. The rate of decline of the analyzed pollutants concentrations is estimated with the use of nonparametric linear regression. Analysis showed that the rate of decline in the average annual concentrations of PM10 and BaP (PM10) in Cracow is always higher than for the analyzed cities of the Malopolskie Voivodeship. The difference is more pronounced with regard to the months of the heating season. The rate of changes for the average annual BaP (PM10) concentrations in Cracow, compared to other analyzed cities of the Malopolskie Voivodeship, is more intensive than in the case of PM10 concentrations (1.5 times stronger with regard to the months of the heating season). Since the concentration of BaP (PM10) is a better indicator of the effects of liquidation of high-emission furnaces than the concentration of PM10, it can be concluded that the impact of actions related to the improvement of air quality in Cracow in the context of changes taking place in selected cities of the Malopolskie Voivodeship is more visible.

The Influence of Heating Degree Days on Fuelwood Consumption in Households in Selected Countries of Central and Southeastern Europe

Serbia is one of the few European countries that does not keep official statistics and does not have data on heating degree days. A heating degree day (HDD) represents a measure to quantify the energy needs for heating a building. In order to create a database, six meteorological stations in Serbia had been selected, for which the heating degree days were calculated for every year in the period 2010-2018. The months with the highest values of heating degree days were also determined for each year of the analyzed period. In addition to the annual level, heating degree days in the heating seasons over the analyzed period were calculated for the six selected stations, as well as the length and the average air temperature of each heating season. In Serbia, heating season officially lasts from October 15 to April 15. To determine the influence of the calculated annual heating degree days on fuelwood consumption in households in Serbia, over the period 2010-2018, multiple econometric models were formulated. The influence of the annual values of heating degree days on fuelwood consumption for household space heating in Slovenia and Croatia was analyzed, as well. The analysis of energy consumption in the households of the selected countries showed that wood fuels are mostly used for heating, primarily fuelwood. This is the reason why this type of fuel was selected for the research.

INFLUENCE OF APARTMENTS’ MODERNIZATION ON THE TEMPERATURES OF HEATING SYSTEM IN THE BUILDING

When modernizing apartment buildings, heating appliances are replaced or old ones are left, high thermal temperatures are usually maintained, thus limiting the increase in the DH system’s efficiency. In the article, in order to evaluate the impact of the reduced thermal temperature of the building on space heating when the radiator area remains constant, 3 alternatives have been analyzed. They include cases when after the building modernization old heating appliances are left, but the temperature of the heat carrier is reduced up to 60/40/20 °C in one case or even up to 45/25/20 in another alternative. There has also been examined the possibility of reducing the heat carrier temperature of the heating system without modernization of the building. An hourly data analysis of the heating system model for two typical months of the heating season has been performed. The analysis shows that after the modernization of the building, when heating device areas are left the same, the existing heating temperature can be reduced to 60/40/2020 °C.

The Effect of External Blinds on Selected Parameters of the Indoor Environment of an office Building

This contribution focuses on the indoor environmental quality in summer due to overheating of the interior of a west-facing office, since buildings designed in passive standard do not have a problem in the winter heating season but have a problem with cooling in the summer season. Therefore, the article focuses on the effect of external blinds on the indoor environmental parameters.

Development of a Natural Soil Depressurization System Sizing Tool

This paper presents a summary of the main developments and results achieved in the frame-work of the French research project called EVAL-SDS. This project aims to analyse the performance of Natural, i.e. without use of fan for extraction, Soil Depressurization Systems (NSDS) to protect the built indoor environment from soil gaseous pollutant (Radon, Volatile Organic Compounds…). In this paper, the aeraulic performance of NSDS is studied i.e. its capacity to extract air from the ground to protect building’s occupants. To this end, we first performed measurements of airflow rates extracted by a NSDS integrated in a test-house during one year. Those data include various weather conditions (stack effect, wind) for several key parameters (wind extractor type, slab air permeability and basement pressure). Then, a dedicated calculation tool has been developed and validated against the experimental results. This numerical model has been used to evaluate the NSDS performance in France for different building heights and ventilation systems. The results show that NSDS succeed in creating a negative pressure under the building slab most of the time and that the extracted airflow rates can be enhanced by better design of wind extractor, association with mechanical insufflating ventilation system and thermal transfer from the building during the heating season.