scholarly journals Air Exchange Rate in Air Quality Assurance – A Case Study

2018 ◽  
Vol 8 (1) ◽  
pp. 13-18
Author(s):  
I. L. Cîrstolovean ◽  
M. Horneț ◽  
Ana Diana Ancas ◽  
M. Profire
Keyword(s):  
Exchange Rate ◽  
Air Quality ◽  
Heat Load ◽  
Natural Ventilation ◽  
Mechanical Energy ◽  
Ventilation System ◽  
Time Interval ◽  
Indoor Temperature ◽  
Air Exchange Rate ◽  
Air Exchange

Abstract The goals of this paper are to estimate some parameters – indoor temperature and ventilation rate - necessary to determine the heat load demand for ventilation in the amphitheatre named ‘A TALPOSI’-Faculty of Buildings Engineering- with a number of at the most 120 occupants. The study presented in this paper is made when in the amphitheatre it is necessary to assure a comfortable temperature by a permanent functioning of the heating system. The number of air exchanges necessary in the amphitheatre in the natural ventilation process, more exactly, to assure a minimum air exchanges, is imposed by the requirements for the assurance of physiologic comfort in the amphitheatre for the time interval when it is occupied by students. The inner air debit should cover the harmful emissions in the amphitheatre. By the help of these calculated (measured) parameters we have calculated the heat load for ventilation. In the end, with the data obtained from calculations and measurements we find ourselves in the situation of establishing the size of the heat exchanger corresponding to the room, to heat the fresh air taken from outside and send it inside the amphitheatre. The measurements are made with the TESTO apparatus of the faculty. The minimum requirements to assure the thermal comfort are: to achieve a minimum internal temperature θi (t) higher than (or equal to) the normal indoor temperature associated to this space and to assure the air quality, the air exchange rate. The authors want to highlight by this study the necessity and importance of the control on the number of air exchanges in rooms with a high number of occupants and overall, the control of the fresh air debits. The fact that the focus is more and more on heat loss cuts in rooms by tightening closing elements gives birth to the necessity of control of the ventilation system with effects on the consumption of mechanical energy.

scholarly journals An Unobstructive Sensing Method for Indoor Air Quality Optimization and Metabolic Assessment within Vehicles

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7202
Author(s):  
Yue Deng ◽  
Mark Sprowls ◽  
S. Jimena Mora ◽  
Doina Kulick ◽  
Nongjian Tao ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Air Quality ◽  
Metabolic Rate ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Accumulation Rate ◽  
Ventilation System ◽  
Reference Method ◽  
Air Exchange Rate ◽  
Air Exchange

This work investigates the use of an intelligent and unobstructive sensing technique for maintaining vehicle cabin’s indoor air quality while simultaneously assessing the driver metabolic rate. CO2 accumulation patterns are of great interest because CO2 can have negative cognitive effects at higher concentrations and also since CO2 accumulation rate can potentially be used to determine a person’s metabolic rate. The management of the vehicle’s ventilation system was controlled by periodically alternating the air recirculation mode within the cabin, which was actuated based on the CO2 levels inside the vehicle’s cabin. The CO2 accumulation periods were used to assess the driver’s metabolic rate, using a model that considered the vehicle’s air exchange rate. In the process of the method optimization, it was found that the vehicle’s air exchange rate (λ [h−1]) depends on the vehicle speeds, following the relationship: λ = 0.060 × (speed) − 0.88 when driving faster than 17 MPH. An accuracy level of 95% was found between the new method to assess the driver’s metabolic rate (1620 ± 140 kcal/day) and the reference method of indirect calorimetry (1550 ± 150 kcal/day) for a total of N = 16 metabolic assessments at various vehicle speeds. The new sensing method represents a novel approach for unobstructive assessment of driver metabolic rate while maintaining indoor air quality within the vehicle cabin.

scholarly journals First steps in the development of a possible measurement method to estimate the radon concentration as an indicator of the indoor air quality

2014 ◽  
Vol 29 (suppl.) ◽  
pp. 52-58
Author(s):  
Franz Roessler ◽  
Jai Azzam ◽  
Volker Grimm ◽  
Hans Hingmann ◽  
Tina Orovwighose ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Energy ◽  
Air Pollutant ◽  
Daily Routine ◽  
Air Exchange Rate ◽  
Pollutant Concentrations ◽  
Air Exchange

The energy conservation regulation provides upper limits for the annual primary energy requirements for new buildings and old building renovation. The actions required could accompany a reduction of the air exchange rate and cause a degradation of the indoor air quality. In addition to climate and building specific aspects, the air exchange rate is essentially affected by the residents. Present methods for the estimation of the indoor air quality can only be effected under test conditions, whereby the influence of the residents cannot be considered and so an estimation under daily routine cannot be ensured. In the context of this contribution first steps of a method are presented, that allows an estimation of the progression of the air exchange rate under favourable conditions by using radon as an indicator. Therefore mathematical connections are established that could be affirmed practically in an experimental set-up. So this method could provide a tool that allows the estimation of the progression of the air exchange rate and in a later step the estimation of a correlating progression of air pollutant concentrations without limitations of using the dwelling.

scholarly journals Designing Jet Fan Ventilation for an Underground Car Park by CFD Simulations

2018 ◽  
Vol 63 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Miroslava Kmecová ◽  
Michal Krajčík ◽  
Zuzana Straková
Keyword(s):  
Exchange Rate ◽  
High Efficiency ◽  
Ventilation System ◽  
Cfd Simulations ◽  
Air Exchange Rate ◽  
Air Supply ◽  
Car Park ◽  
Computational Fluid Dynamics Cfd ◽  
Alternative Designs ◽  
Air Exchange

The aim of this study was to design a fire ventilation system with impulse jet fans for an underground car park. With respect to the number of parameters affecting the spread of smoke that need to be considered, there is a good chance of miscalculations if only conventional plain calculations are used in the design process. To avoid mistakes, visualize the fluid flow, and to compare the design variants it is practical to use computational fluid dynamics (CFD). In this study, CFD simulations were used to compare alternative designs of a fire ventilation system. In one alternative the exhaust shafts were located in both parts of the car park and the jet fans were directed to the corresponding shafts. The air exchange rate was 10-times per hour. In another alternative both exhaust shafts were located on one side opposite to the main air supply, and the air exchange rate was 15-times per hour. The results showed preference of the second alternative, when the smoke was completely exhausted and the visibility improved substantially, whereas in the first alternative the car park was not sufficiently ventilated even 600 seconds after the fire had been put out. The results emphasize that proper location of elements of the ventilation system is crucial to attain high efficiency of fire ventilation.

scholarly journals ЕКСПЕРИМЕНТАЛЬНЕ ДОСЛІДЖЕННЯ ЯКОСТІ ПОВІТРЯ ТА ПОВІТРООБМІНУ В ЗАКЛАДАХ ОСВІТИ ТА ЖИТЛОВИХ БУДІВЛЯХ

2021 ◽  
Vol 148 (4) ◽  
pp. 25-37
Author(s):  
В. І. Дешко ◽  
І. Ю. Білоус ◽  
В. О. Виноградов-Салтиков ◽  
І. О. Суходуб ◽  
О. І. Яценко
Keyword(s):  
Mathematical Modeling ◽  
Exchange Rate ◽  
Energy Consumption ◽  
Air Quality ◽  
Operating Conditions ◽  
Change Rate ◽  
Research Results ◽  
Air Exchange Rate ◽  
Air Change Rate ◽  
Air Exchange

Apply  integrated  approaches  for  the  air  exchange  rate  determination  based  on  CO 2  concentration in educational and residential buildings of Ukraine. Methods.  Taking  into  account  variability  of  building's  visitors  and  occupants  operational  and behavioral features experimental and calculated determination of the air exchange rate are considered. Results. Recommendations for providing comfort conditions in terms of air quality in the considered objects premises, recommendations on the premises operating conditions, ventilation schedule. Scientific novelty. The comprehensive approach to in-depth analysis of energy consumption has been developed,  procedures for assessing  the  air  quality  and  the level  of  air  exchange  in  buildings  have  been improved taking into account the variability of operating conditions. The practical significance. Experimental studies of changes in CO 2  concentration were conducted in three schools, in higher education institution and in residential building. The research results allowed to establish the actual level of CO 2  concentration and air change rate under different operational and behavioral conditions in buildings during working hours, subject to comfortable conditions, and during non-use hours. The research results also help to determine the dynamics of changes in the studied factor over time under the building  performance  indicators  influence.  The  obtained  results  allow  to  provide  recommendations  on ensuring the quality of indoor air exchange and on providing comfort working, studying and living conditions. The use of experimental and calculated air exchange rate values for various premises would allow to avoid in mathematical modeling the overestimation of the level of buildings energy consumption, which arises when standard air change rate values is using. So the obtained results allow to approximate more accurately the mathematical modeling results of buildings energy efficiency to the actual conditions and help to choose the optimal schedule for the building engineering networks managing considering comfort conditions with intermittent operation.

Indoor climate and air quality in new offices: effects of a reduced air-exchange rate

1991 ◽  
Vol 63 (4) ◽  
pp. 233-239 ◽  
Author(s):  
B. M. Berardi ◽  
E. Leonie ◽  
B. Marchesini ◽  
D. Cascella ◽  
G. B. Raffi
Keyword(s):  
Exchange Rate ◽  
Air Quality ◽  
Indoor Climate ◽  
Air Exchange Rate ◽  
Air Exchange

Air Exchange across Staircase Windows in Protected Escape Route in Time of Fire

2013 ◽  
Vol 855 ◽  
pp. 215-218
Author(s):  
Martina Reháková ◽  
Imrich Mikolai
Keyword(s):  
Exchange Rate ◽  
Temperature Difference ◽  
Natural Ventilation ◽  
Escape Route ◽  
Wind Action ◽  
Air Exchange Rate ◽  
Rate Calculation ◽  
Air Exchange

The article is focused on the analysis of air exchange by natural ventilation in the staircase area with elevator in the middle as a protected escape route. The article contains three variants of air exchange rate calculation that are based on the effect of the temperature difference and the effect of wind action. The result of these calculations is the verification if the staircase windows provide sufficient air exchange in the protected escape route to ensure the required level of protection for evacuees.

Experimental Quantification of Air Permeability of Building Envelope with Installed Controlled Ventilation System - Case Study

2019 ◽  
Vol 887 ◽  
pp. 571-578
Author(s):  
Boris Bielek ◽  
Daniel Szabó
Keyword(s):  
Exchange Rate ◽  
Residential Buildings ◽  
Ventilation System ◽  
Air Permeability ◽  
Building Envelope ◽  
Test Method ◽  
Air Exchange Rate ◽  
Controlled Ventilation ◽  
Air Infiltration ◽  
Air Exchange

To meet the increasingly stringent requirements of standard energy consumption and thus reducing operating costs of buildings, it is necessary to use energy-saving elements of technical equipment and eliminate heat loss through the building envelope. The biggest losses are caused by heat transmission and ventilation in the form of uncontrolled air infiltration through the building envelope. Their elimination can be achieved by improving the thermal technical quantification of building envelope and increase its airtightness. Determination of air permeability as a measure of quality building envelope is possible using the method of measuring devices Blower-Door test. Any defects can be detected by detection tools, then propose a suitable method for their removal and thus prevent unwanted unregulated air infiltration into the interior. On the other hand, are opposed to the health requirements required air exchange in the room, which is a significant reason for the transformation of this mode of ventilation by uncontrolled air infiltration to a controllable ventilation system. The subject of the paper is in-situ measurement of air permeability of specific apartment envelope by Blower-Door test method and comparison the efficacy of the installed controlled ventilation system and hygiene requirements of the ventilation intensity for residential buildings. Laboratory verification of façade ventilation unit parameters in big pressure chamber - measurement of inlet ventilation flap airflows at variable pressure differences. Methodology for the measurement by Blower-Door test method to determine the air permeability of building envelope structures and functionality of controlled ventilation system was based on a series of 10 measurements in 5 regimes. The overall air permeability of the building envelope or its integrated part may be verified using the total air exchange rate n50at 50 Pa pressure difference, determined experimentally according to STN EN 13829. Comparison of measured values with standard values recommended by some European countries with a similar climate with sealed and with unsealed ventilation flaps, which can determine the impact on the overall airtightness of the building envelope. Calculation of total hygiene required air exchange rate of the apartment and its comparison with actual measured values by Blower-Door test method.

Sign in / Sign up

Export Citation Format

Share Document