scholarly journals Indoor Air Quality Assessment in a Single-Family House Equipped with Demand Controlled Mechanical Ventilation

2020 ◽  
Vol 27 (3) ◽  
pp. 387-402
Author(s):  
Jarosław Müller ◽  
Maciej Dębowski

AbstractThe paper presents the results of modelling airflow for ventilation of a single-family house with an area of 180 m2. The building was equipped with mechanical ventilation with the possibility of varying the airflow. The airflow was calculated as a function of carbon dioxide concentration. The presence of people in selected rooms was an internal source of carbon dioxide. In order to properly design of a ventilation system and then model the contamination level, ContamW software was used. The year-long cost analysis was carried out for the installation working with variable airflow (day, night). The analysis took into account the price of the electricity used by the fans of Air Handling Unit and meteorological data to estimate the power input to the heater of the Unit. Different scenarios of system operation were included as an input data in order to find a difference in energy consumption. The calculations were to answer the question of whether it is necessary to apply expensive and advanced system that enables individual control of the airflow in every room or use the simple control of the central unit to vary the airflow in the ventilation system of single-family houses. The difference in operating cost between the system that maintains 800 and 600 ppm reaches 100 % and demonstrates the need of simple demand controlled ventilation system.

Author(s):  
A. B. Sulin ◽  
◽  
A. A. Nikitin ◽  
T. V. Ryabova ◽  
S. S. Muraveinikov ◽  
...  

A method for controlling the ventilation system flow characteristics is considered based on the forming principle an air temperature and carbon dioxide concentration predicted estimate in a room based on the changes dynamics analysis in these parameters in the supply and exhaust ducts. The expected microclimate parameters predicted assessment in real time opens up the possibility of using such elements and algorithms for controlling the ventilation and air conditioning system, which provide the required air quality with minimal energy consumption. The analysis calculates the finding probability the measured parameter inside or outside the control zone after a specified time interval. The algorithm for the control system actuators actuation for the channels of temperature and carbon dioxide concentration is presented in the block diagram form. The decision-making logic for actuating the actuators is based on the changes direction and intensity analysis in temperature and carbon dioxide concentration in the exhaust duct and the temperature difference between the supply and exhaust


Author(s):  
Katarzyna Gładyszewska-Fiedoruk ◽  
Sebastian Jachimowicz

Children in kindergartens spend between five and ten hours a day, the quality of air inside is very important. Kindergartens are public buildings. Kindergartens in Poland do not have mechanical ventilation, most often use stack ventilation, which is frequently aided by airing. The three considered buildings were located in eastern Europe. The main objective of the research was to evaluate the interior conditions, especially with regard to carbon dioxide concentration. In the afternoon, the permissible level of carbon dioxide concentration was substantially exceeded (by 190% at the most in first series of measurement). The present research has resulted in considerable improvement of indoor conditions in the analyzed kindergartens (less than 140% in third series of measurement). The presence of children and ventilation habits seemed to be the main determinants of IAQ and carbon dioxide.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2845 ◽  
Author(s):  
Katarzyna Gładyszewska-Fiedoruk ◽  
Vasyl Zhelykh ◽  
Andrii Pushchinskyi

The quality of internal air is one of the factors that affect the pace and quality of knowledge acquisition. Therefore, it is important that classrooms have high quality of air. Using computer simulation, the effect of various building ventilation variants on air quality in classrooms was analyzed. Two criteria were analyzed and six variants of ventilation. The analysis was carried out using the CONTAMW program, used for multi-zone analysis of ventilation and air quality in a building. As an indicator of air quality, the concentration of carbon dioxide in school halls was adopted. The analyses show that natural ventilation is not able to provide proper air exchange. Regular airing of classrooms during breaks can reduce the carbon dioxide concentration to 2500 ppm, however, there is a significant reduction in indoor temperature (even below 10 °C). The best control over the internal environment can be obtained by using a supply–exhaust ventilation system with heat recovery. Obtaining a higher stabilization of ventilation is achieved by supplying additional energy to drive fans, however, this is only a small amount of energy compared to the cost of heat for heating the building (maximum 2%).


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 105
Author(s):  
Aldona Skotnicka-Siepsiak

In the present study, the real-world performance of a ground-to-air heat exchanger (GAHE) was analyzed in the Polish climate which is characterized by warm summers and cold winters. The heat exchanger’s performance was monitored over a period of three years (2017 to 2019), and real-world conditions were compared with a Typical Meteorological Year (TMY). The aim of the study was to assess the exchanger’s energy-efficiency potential in various ventilation scenarios in a single-family home under variable real-world conditions, rather than to simply determine its heating and cooling capacity. The analyzed single-family home was a modern, single-story building with a usable floor area of 115 m2. The building’s thermal insulation and airtightness met stringent energy-efficiency standards. Energy consumption in a building equipped with a natural ventilation system was compared with three other scenarios: ventilation coupled with a GAHE, mechanical ventilation with heat recovery and a high-efficiency heat exchanger (HE), and mechanical ventilation with heat recovery coupled with a GAHE. Sensible heating and cooling loads were calculated based on standard ISO 13790:2008, and latent heating and cooling loads were also included in the energy balance. During the year, the GAHE generated around 257.6 W of heating energy per hour and 124.7 W of cooling energy per hour. Presented results can be used to select the optimal HVAC system scenarios for engineering projects as well as private investors.


Sign in / Sign up

Export Citation Format

Share Document