The use of occupant-exhaled CO2 as the tracer gas enables the actual indoor infiltration rate to be measured, but the number and location of measuring points have a great impact on the accuracy of the results. This paper compares the experimental results from two tracer gas measurement techniques, decay with SF6 and constant injection with CO2 (exhaled by occupant). The results show a deviation of –9.0 to 7.4% between these two methods. This paper compares the result of this study with previous ones, and it confirmed that the CO2 method is an effective technique to calculate the infiltration rate in a room with a certain air volume when one measuring point is provided, and this is more accurate with good mixing of the indoor air. The impact of the measurement duration and distribution of indoor air on the measurement accuracy are also analysed. It is found that an extended monitoring period can reduce the impact of indoor air distribution. In actual measurements in residential building, it is recommended to select the data after occupants have been in the room for half an hour and to take measurements over 1 h after that.
Practical application: Accurate air change per hour (ACH) is beneficial to the study of building energy consumption and indoor air quality. This paper explores the effectiveness of CO2 method, which provides useful reference for the large sample measurements of infiltration rates in residential buildings.
Handbook-fundamentals. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc, 2009.
2.
BakerPSharplesSWardI.Air flow through cracks. Build Environ1987;
22: 293–304.
3.
SeppänenOFiskWMendellM.Association of ventilation rates and CO2 concentrations with health and other responses in commercial and institutional buildings.Indoor Air1999;
9: 226–252.
4.
DimitroulopoulouC.Ventilation in European dwellings: a review. Build Environ2012;
47: 109–125.
5.
WargockiPSundellJBischofW, et al.
Ventilation and health in non-industrial indoor environments: report from a European Multidisciplinary Scientific Consensus Meeting (EUROVEN).Indoor Air2002;
12: 113–128.
6.
ShermanMH.Tracer-gas techniques for measuring ventilation in a single zone. Build Environ1990;
25: 365–374.
7.
HongGKimBS.Field measurements of infiltration rate in high rise residential buildings using the constant concentration method. Build Environ2016;
97: 48–54.
8.
CuiSCohenMStabatP, et al.
CO2 tracer gas concentration decay method for measuring air change rate. Build Environ2015;
84: 162–169.
9.
LaportheSVirgoneJCastanetS.A comparative study of two tracer gases: SF6 and N2O. Build Environ2001;
36: 313–320.
10.
EdouardNMosqueraJvan DoorenHJ, et al.
Comparison of CO2-and SF6-based tracer gas methods for the estimation of ventilation rates in a naturally ventilated dairy barn. Biosyst Eng2016;
149: 11–23.
11.
DervosCTVassiliouP.Sulfur hexafluoride (SF6): global environmental effects and toxic byproduct formation.J Air Waste Manag Assoc2000;
50: 137–141.
12.
ProvanTYoungerJ.Air infiltration characteristics of windows. Energy Build1986;
9: 281–292.
13.
JohnsonTMyersJKellyT, et al.
A pilot study using scripted ventilation conditions to identify key factors affecting indoor pollutant concentration and air exchange rate in a residence.J Expos Sci Environ Epidemiol2004;
14: 1.
14.
Le HouérouHN.Climate change, drought and desertification. J Arid Environ1996;
34: 133–185.
15.
ShugartHHEmanuelWR.Carbon dioxide increase: the implications at the ecosystem level. Plant Cell Environ2010;
8: 381–386.
16.
StavovaP.A method for air change rate measurements in dwellings based on carbon dioxide produced by people. Master Thesis.
Denmark:
Technical University of Denmark, 2004.
17.
BekoGLundTNorsF, et al.
Ventilation rates in the bedrooms of 500 Danish children. Build Environ2010;
45: 2289–2295.
18.
ChengPLLiX.Air infiltration rates in the bedrooms of 202 residences and estimated parametric infiltration rate distribution in Guangzhou, China. Energy Build2018;
164: 219–225.
19.
AiZMakCCuiD, et al.
Ventilation of air-conditioned residential buildings: a case study in Hong Kong. Energy Build2016;
127: 116–127.
20.
ChengPLLiX.Air change rate measurements using tracer gas carbon dioxide from dry ice. Int J Ventil2014;
13: 235–246.
21.
TurkAEdmondsSMMarkHL, et al.
Sulfur hexafluoride as a gas-air tracer. Environ Sci Technol1968;
2: 44–48.
22.
HuntCTreadoS.A prototype semi-automated system for measuring air infiltration in buildings using sulfur hexafluoride as a tracer. Final technical note. Washington, DC: National Bureau of Standards, 1976.
23.
BaránkováPNaydenovKGMelikovAK, et al. Distribution of carbon dioxide produced by people in a room: part 1: laboratory study. In: 9th International conference on air distribution in rooms, University of Coimbra, Coimbra, Portugal, 5–8 September 2004.
24.
BarankovaPMelikovAKSundellJ, et al. New method for ventilation measurement in homes based on CO2 produced by people-laboratory study. In: 17th air-conditioning and ventilation conference, Prague, Czech Republic, 17–19 May 2006.
25.
HouJSunYKongX, et al.
Single and multiple zone methods to calculate air change rate in apartments. Proc Eng2015;
121: 567–572.
26.
RemionGMoujalledBMankibiME.Review of tracer gas-based methods for the characterization of natural ventilation performance: comparative analysis of their accuracy. Build Environ2019;
160: 106180.
27.
ClaudealainRForadiniF.Simple and cheap air change rate measurement using CO2 concentration decays. Int J Ventil2002;
1: 39–44.
28.
GuoLLewisJO.Carbon dioxide concentration and its application on estimating the air change rate in typical Irish houses. Int J Ventil2007;
6: 235–245.
29.
LaussmannDHelmD.Air change measurements using tracer gases: methods and results. Significance of air change for indoor air quality.
London, UK:
InTech, 2011.
30.
StavovaP. Experimental Evaluation of Ventilation in Dwellings by Tracer Gas CO2. Czech Technical University, Czech Republic 2011.
31.
HongGKimDD.Airtightness of electrical, mechanical and architectural components in South Korean apartment buildings using the fan pressurization and tracer gas method. Build Environ2018;
132: 21–29.
32.
HeidtFWernerH.Microcomputer-aided measurement of air change rates. Energy Build1986;
9: 313–320.
33.
SandbergMBlomqvistC.A quantitative estimate of the accuracy of tracer gas methods for the determination of the ventilation flow rate in buildings. Build Environ1985;
20: 139–150.
34.
CAN/CGS-149.10. Determination of the airtightness of building envelopes by the fan depressurization method, 1986.
35.
Kenkyūjo KGS. Toxic and hazardous industrial chemicals safety manual for handling and disposal with toxicity and hazard data.
Tokyo:
International Technical Information Institute, 1982.
36.
HouJZhangYSunY, et al.
Air change rates in residential buildings in Tianjin, China. Proc Eng2017;
205: 2254–2258.
37.
QiMLiXWeschlerLB, et al.
CO2 generation rate in Chinese people.Indoor Air2014;
24: 559–566.
38.
PersilyAde JongeL.Carbon dioxide generation rates for building occupants.Indoor Air2017;
27: 868–879.
39.
ZhouY.Research on the air ventilation measurement using tracer gas decay method and its improvement.
Shanghai, China:
University of Shanghai for Science and Technology2013.
40.
MahyuddinNAwbiH.A review of CO2 measurement procedures in ventilation research. Int J Ventil2012;
10: 353–370.
41.
Sampling ACD-o and Air AoASDoI. Standard guide for using indoor carbon dioxide concentrations to evaluate indoor air quality and ventilation, ASTM, 1998.
