The Usage of CO2 Tracer Gas Methods for Ventilation Performance Evaluation in Apartment Buildings

2017 ◽  
Author(s):  
Alo Mikola ◽  
Teet-Andrus Kõiv ◽  
Juhan Rehand ◽  
Hendrik Voll
Keyword(s):  
Performance Evaluation ◽  
Natural Ventilation ◽  
Correct Result ◽  
Tracer Gas ◽  
Exhaust Ventilation ◽  
Apartment Buildings ◽  
Gas Measurements ◽  
Ventilation Performance ◽  
Natural Tracer

The purpose of the study is to investigate the potential of the CO2-based tracer gas methods for the ventilation performance evaluation in apartment buildings. To test and elaborate the methods, the ventilation air change rate (ACR) and air change efficiency (ACE) measurements were performed. The methods were tested in laboratory conditions and apartments with natural ventilation, room-based ventilation units, exhaust ventilation and mechanical exhaust ventilation with fresh air radiators. Concentration decay method is applied with both artificially and naturally increasing the concentration of tracer gas. The ACR is also calculated using metabolic constant dosing method with the effective volume. As the traditional tracer gas methods give the correct result only in case of perfect mixed ventilation, then the ACE is also measured. To observe the effectiveness of the air change and the level of air mixing multiple CO2 sensors placed in different positions. The tracer gas measurements were carried out in naturally ventilated apartments to study the influence of the inner doors to the ACE. The daily variation of CO2 level in case the long-term CO2 measurements gives us the possibility to calculate the ACR when inhabitants are sleeping or have left the apartment. Using the CO2 as the natural tracer gas and the concentration decay method together with the metabolic constant dosing strategy, we can calculate the CO2 concentrations according to the long-term CO2 measurements without knowing the exact emission of inhabitants. The studied methods are inexpensive and at the same time sufficiently accurate for airflow measurements. Another reason for the study comes from the ventilation retrofit process in Estonia where the single room ventilation units are used. As these wall-mounted ventilation units are sensitive to in- and outside pressure differences the measurement of ventilation airflow in the traditional way can be inaccurate.

Comparison of Measured and Calculated Air Changes due to Single Sided Window Openings - A Case Study

2019 ◽  
Vol 887 ◽  
pp. 492-499
Author(s):  
Matthias Schuss ◽  
Alexandra Balmus ◽  
Farhang Tahmasebi ◽  
Ardeshir Mahdavi
Keyword(s):  
Natural Ventilation ◽  
Building Simulation ◽  
Estimation Methods ◽  
Building Performance ◽  
Tracer Gas ◽  
Measured Concentration ◽  
Current Contribution ◽  
Gas Measurements ◽  
Proper Values

The present paper focuses on the evaluation of different methods for calculation of air change rates due to natural ventilation through windows. Such estimations are of utmost importance for the studies, in which the influence of window operation on thermal comfort, air quality and building performance is to be addressed. Especially, to build accurate building performance models and to develop reliable building simulation scenarios, it is crucial to predict proper values of air exchange. A number of standards and recent scientific contributions present various models for the estimation of air change rates, whereby different sets of input parameters related to room and outdoor conditions are needed. The current contribution examines the reliability of calculated air change rates obtained via a number of widely used estimation methods for a case study room with single sided windows. To this end, a number of tracer gas measurements in a variety of window state settings were conducted, and the real air change rates were calculated based on the measured concentration decay of the tracer gas. Consequently, using the resulting measured and calculated values of air change rates, the reliability of estimation methods could be extensively explored.

Numerical investigation of wind-driven natural ventilation performance in a multi-storey hospital by coupling indoor and outdoor airflow

2016 ◽  
Vol 25 (8) ◽  
pp. 1226-1247 ◽  
Author(s):  
Ruiqiu Jin ◽  
Jian Hang ◽  
Shanshan Liu ◽  
Jianjian Wei ◽  
Yang Liu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Ventilation ◽  
Tracer Gas ◽  
Indoor Airflow ◽  
Change Rate ◽  
Air Change Rate ◽  
Airflow Field ◽  
Ventilation Performance ◽  
Dynamics Simulations

This study employed two ventilation indexes: local mean age of air and air change rate per hour, to investigate wind-induced natural ventilation of 260 wards of a multi-storey hospital building in suburb of Guangzhou using computational fluid dynamics simulations. Using the surface-grid extrusion technique, high-quality hexahedral grid cells were generated for the coupled outdoor and indoor airflow field. Turbulence was solved by the renormalisation group k-ɛ model validated against experimental data with grid independence studies. Homogeneous tracer gas emission was adopted to predict room age of air. The air change rate of cross ventilation and single-sided ventilation can reach 30–160 h−1 and 0.5–7 h−1, respectively. Due to different locations of room openings on the balconies, natural ventilation of a room can be greatly better than its neighbouring room. The wind-induced cross ventilation highly depends on the distance from the room opening to the stagnation point and on the resulting pressure distribution on the target building surface. Furthermore, it is significantly influenced by the upstream buildings, the bent shape of the target building, and the prevailing wind directions. The coupled computational fluid dynamics methodologies with integrated ventilation indexes are useful for assessing the natural ventilation performance in other complex built environments.

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance

Design and planning of the balanced scorecard: A case study

2007 ◽  
Vol 26 (3) ◽  
pp. 217-227
Author(s):  
Ming-Hon Hwang ◽  
Hsin Rau
Keyword(s):  
Performance Evaluation ◽  
Balanced Scorecard ◽  
Process Management ◽  
Planning Process ◽  
Company Performance ◽  
Correct Process ◽  
The Balanced Scorecard ◽  
Strategy Planning ◽  
And Performance

In the industrial economy, evaluating company performance based on financial results was good enough. However, in the current globalized and highly competitive environment, maintaining long term competitiveness requires companies to engage in overall strategic planning and performance evaluation. The balanced scorecard is a tool or method for balancing an organization's performance and can react to situations where a company's direction becomes disoriented. This approach assists in strategy planning, process management, and performance evaluation from four perspectives, including financial, customer, internal process, and learning and growth. Good strategy planning provides companies with a correct management direction, correct process management ensures the efficient execution of plans, and correct performance evaluation illustrates the execution results. This study mainly focuses on how a large rubber company in Taiwan utilizes the balanced scorecard in its organization. As the technical perspective is important in the rubber keypad industry, besides the four above perspectives, this company has added the technical perspective. By introducing this company and its progress in implementing the balanced scorecard, this study hopes to provide other companies, especially rubber companies, with a planning direction and reference for the future implementation of the balanced scorecard.

scholarly journals Comparison of Downdraught and Up Draft Passive Air Conduction Systems (PACS) in a Winery Building

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 259
Author(s):  
Ádám László Katona ◽  
István Ervin Háber ◽  
István Kistelegdi
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
General Applicability ◽  
Change Rate ◽  
Air Change Rate ◽  
Simulation Based ◽  
Ventilation Performance ◽  
Air Conduction

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.

scholarly journals Thermal Performance of Single-Story Air-Welled Terraced House in Malaysia: A Field Measurement Approach

2020 ◽  
Vol 13 (1) ◽  
pp. 201
Author(s):  
Pau Chung Leng ◽  
Gabriel Hoh Teck Ling ◽  
Mohd Hamdan Ahmad ◽  
Dilshan Remaz Ossen ◽  
Eeydzah Aminudin ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Thermal Performance ◽  
Field Measurement ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Wet Bulb Globe Temperature ◽  
Natural Lighting ◽  
Ventilation Performance ◽  
Globe Temperature

The provision requirement of 10% openings of the total floor area stated in the Uniform Building By-Law 1984 Malaysia is essential for natural lighting and ventilation purposes. However, focusing on natural ventilation, the effectiveness of thermal performance in landed residential buildings has never been empirically measured and proven, as most of the research emphasized simulation modeling lacking sufficient empirical validation. Therefore, this paper drawing on field measurement investigates natural ventilation performance in terraced housing with an air-well system. The key concern as to what extent the current air-well system serving as a ventilator is effective to provide better thermal performance is to be addressed. By adopting an existing single-story air-welled terrace house, indoor environmental conditions and thermal performance were monitored and measured using HOBO U12 air temperature and humidity, the HOBO U12 anemometer, and the Delta Ohm HD32.3 Wet Bulb Globe Temperature meter for a six-month duration. The results show that the air temperature of the air well ranged from 27.48 °C to 30.92 °C, with a mean relative humidity of 72.67% to 79.25%. The mean air temperature for a test room (single-sided ventilation room) ranged from 28.04 °C to 30.92 °C, with a relative humidity of 70.16% to 76.00%. These empirical findings are of importance, offering novel policy insights and suggestions. Since the minimum provision of 10% openings has been revealed to be less effective to provide desirable thermal performance and comfort, mandatory compliance with and the necessity of the bylaw requirement should be revisited.

Analysis of the Ventilation Effects on Radon-222 Exhalation in a Dead-End Tunnel

2015 ◽  
Vol 713-715 ◽  
pp. 304-313
Author(s):  
Shu Guang Wang ◽  
Wei Yang ◽  
Qing Chen ◽  
Jian Hua Chen ◽  
Cong Han
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Natural Ventilation ◽  
Weather Conditions ◽  
Calculation Model ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Exhaust Ventilation ◽  
Dead End

The regularity of radon exhalation rate in the over-broken granite tunnel is susceptible to weather conditions and ventilation styles. Based on the calculation model of radon exhalation in tunnel, some experiments have been carried out to analyze the variations of radon exhalation in cases of natural ventilation, blowing ventilation and exhaust ventilation separately. The results show that there is a linear relation between the radon exhalation and the natural ventilation quantity, and also between the radon exhalation and the ambient temperature; the radon exhalation in the case of exhaust ventilation is 63% higher than that in the blowing case under the condition of the same ventilation quantity and ambient temperature. Therefore, it is suggested that operation in the tunnel in high temperature be avoided in summer, and the blowing ventilation be adopted as an effective way for ventilation.

scholarly journals Long-term experimental performance evaluation of aerogel insulation plaster

2017 ◽  
Vol 132 ◽  
pp. 508-513 ◽  
Author(s):  
M. Schuss ◽  
U. Pont ◽  
A. Mahdavi
Keyword(s):  
Performance Evaluation ◽  
Experimental Performance
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