Comprehensive Study of the Microclimate Parameters in the Residential Building


 The relevance of the research lies in the development of the current question about the influence of microclimate quality on the efficiency of residential units. The aim of the study is to examine how the microclimate parameters affect the efficiency of residential buildings. Findings. The results obtained are essential for the design of energy-efficient and comfortable residential buildings. The scientific novelty and practical importance of research resides in the thorough study of microclimate in low-rise residential buildings. Microclimate deviation charts for residential buildings have been produced.


Introduction
The EU has made a commitment to reduce greenhouse gas emissions from 80% to 95% below 1990 levels by 2050 [6]. Residential buildings contribute significantly to greenhouse gas emissions. That's why energy consumption in buildings has become a major concern worldwide and policy makers endorse measures to improve the energy efficiency of buildings in order to promote sustainable use of energy [19].
The microclimate inside buildings is an essential factor for building energy efficiency. In recent years, people have faced several serious pandemic-related restrictions and stayed at home for a long time. Nearly everyone could feel how comfortable or uncomfortable it was to stay in his place. Temperature, humidity and concentration of carbon dioxide are factors that influence human well-being and comfort. Some indicators are very individual, for example, temperature. When 18°С is a fairly comfortable temperature for one person, the other feels warm, while it can be pretty cold for the third. The factors that may influence are human metabolism, clothes, air humidity, air velocity, and pollution. These parameters are connected. Thus, the analysis and monitoring of microclimate are essential and relevant since it directly influences human health.
The above topic is complicated and complex. The literature review demonstrates the relevance of the research subject matter. The research studies were focused on:  analysis of thermal losses in buildings [3,4,9,14,18];  analysis of energy efficiency and flexibility of the air conditioning and heating [1,15];  creating and improving calculation methods, algorithms to achieve optimal and effective energy consumption during peak hours [7,8,13,17];  experimental research using modern materials and studying their impact on increasing energy efficiency of buildings [11,16];  developing heat indicators and energy efficiency class limits in buildings [2,5,10,12]. The research papers analyzed point to a lack of studies on the impact of the microclimate of residential buildings on their efficiency.
The aim of the research is to determine how microclimate influences the efficiency of residential buildings.
The subject of the research is the principles of microclimate changes in residential houses.
An object of the research is microclimate parameters and thermal failures of the lowrise residential building.

The methodology
Instrumental monitoring of microclimate parameters (temperature, relative humidity, carbon dioxide concentration) in residential buildings was carried out to analyze how microclimate affects the efficiency of houses [25].
Experimental facility -a residential house in Kherson (II climate zone). The building is located far from main roads on the outskirts of the city. Its total area is 69,9 m 2 ; its living space is 37,6 m 2 . At the time of the experiment, the house was occupied by 6 adults and 5 pets.
The building envelope includes rough masonry (main building and extension №1) and shell masonry (extension №2, kitchen and bathroom). The walls of the house are insulated with 50-mm foam panels. The windows are PVC two-chamber double-glazed, one chamber is filled with argon. The floor of the main building is wooden with some crawl space. The floors in the extension buildings are cement. The roof is garret and double-pitched. The attic is not insulated.
Technical equipment. The measurements were taken with CO2HT-501 digital meter (see fig. 1). This measuring device can simultaneously take readings of temperature, relative humidity, and СО2 concentration level. Necessary software allowed us to analyze the results obtained. The main technical characteristics are given in table 1.  Measurements were taken in three premises (the living spaces and a kitchen). The meter was installed at 1-1,5m height and 1,5m from windows. The measurements were taken every 8 minutes during two 24-hour periods; total number of measurements is 360. We analyzed the results of microclimate monitoring in the living space, consisting of 2 living rooms without doors (19,4 m 2 ). The living room is for 2 people, at the time of the experiment, one person worked at the computer from 8:00 to 17:45. Over the 24-hour period there were constantly from one to four people in the room, as well as four pets. In addition, a gas heater was used. Then we analyzed the results of microclimate monitoring in the service (utility) space, consisting of a hallway, a kitchen (no doors between), and a bathroom. The total area was 16,4 m 2 . There was a gas stove in the kitchen. Over 24 hours, there were from one to five people in the premises. A gas heater was also in use. Ventilation ducts in the kitchen and the bathroom were in poor condition, and there was no exhaust ventilation. Hallway doors were mostly closed. There were five flower pots with indoor plants. Dates of the experiment: Jan 4-5, 2021. Weather conditions: 04.01.21 t = + 1°С, humidity 94%, overcast, no precipitation. 05.01.21 max. t = +4°С, min. t = +1°С, humidity fluctuated from 91% to 97%, overcast, no precipitation.

Results
The results of the microclimate monitoring are presented graphically in fig. 2 for living space and in fig. 3 -for a service (utility) space. The analysis of specific time intervals and extreme values are given in table 2 for living space and in table 3 for a service space.
According to Ukrainian standards [20][21][22], the specified temperature for a residential building is 20°С, an appropriate humidity rate is from 40% to 60% [21]. A recommended level of carbon dioxide is up to 1000 ppm when 1600 ppm is acceptable. To maintain the level of carbon dioxide within 1000 ppm, it is necessary to provide approximately 30 m 3 of fresh air per hour for every person. To keep it within 1600 ppm, it must give around 15 m 3 of fresh air per hour for every person [24].

Conclusion
Instrumental monitoring of three micro-climatic parameters: temperature, relative humidity, and carbon dioxide concentration in Kherson's residential home was carried out.
Based on the results obtained, it was found that only one parameter, which is the temperature of indoor air, meets current standards. On the one hand, the outside walls of the house were insulated, and the windows were replaced with PVC double glazed ones to provide energy efficiency. On the other hand, the tenants of the house have reduced the natural ventilation time in order to save heat energy. All the measures taken contributed to a higher rate of relative humidity -70-80% (standard values -40-60%) and СО2 concentration-3000 -4000 ppm (standard value -not more than 1000 ppm). This last parameter gives the house known as "building-related illness" (from 1500 to 5000 ppm), which adversely affects the health of tenants.
The monitoring has shown the importance of a comprehensive approach to the thermal renovation of buildings. A mechanical supply and waste ventilation system with heat recovery is required for the insulation of the building envelope.