Indoor air quality and ventilation

Transcription

1 Indoor air quality and ventilation requirements Guangyu Cao Department of Energy and Process Engineering, NTNU (November, 10, 2016, Hainan, China)

2 Have you used e-clicker or any audience response/voting device/system? A) Yes often B) Yes seldom C) No D) Not sure 30.0% 40.0% 20.0% 10.0% A B C D 2

3 What is Indoor Air Quality (IAQ)? IAQ = a general denomination for the cleanliness of indoor air. IAQ= an indicator of the types and amounts of pollutants in the air that might cause discomfort or risk of adverse effects on human or animal health, or damage to vegetation. An expression partly for the chemical, physical and microbiological composition of air and partly for people s perception of the air. 3

4 What s your perceived air quality here? A) -1 Clearly not acceptable B) -0.5 Not acceptable C) 0 Just acceptable or just not acceptable D) Acceptable E) + 1 Clearly acceptable A B C D E

5 Indoor air quality and potential pollutants outdoors Industry Energy Reactions in the atmosphere Nature Traffic

6 Potential pollutants indoors Chemicals released from modern buildings & furnishing materials From cleaning products: solvents Pets Fireplace & wood burning Cooking Carbon Monoxide and Nitrogen oxides from vehicles Radon from foundation Mold & bacteria

7 Indoor climate and health - a complex picture Example of the health effects of indoor air pollution (Nilsson, P. (ed)., 2003, Achieving the Desired Indoor Climate) asthma Pollen allergy Odours Irritation Toxic hazard

8 Have you experienced any of the following syndrome: A) Asthma B) Pollen allergy 30 C) Dust allergy D) Eye iritation 20 E) Ear iritation F) Not sure G) Never 0 A B C D E F G

9 Which disease is the most common one (caused by indoor air pollution) that may cause death? A) stroke ( 中风 ); B) ischaemic heart disease ( 缺血性心脏病 ); C) chronic obstructive pulmonary disease COPD ( 慢性障碍性肺病 ); D) acute lower respiratory infections in children ( 儿童急性下呼吸道感染 ); and E) lung cancer( 肺癌 ). WHO: 7 million premature deaths annually linked to air pollution (2014) Indoor air pollution-caused deaths breakdown by disease: a) 34% - stroke ( 中风 ); b) 26% - ischaemic heart disease ( 缺血性心脏病 ); c) 22% - COPD ( 慢性障碍性肺病 ); d) 12% - acute lower respiratory infections in children ( 儿童急性下呼吸道感染 ); and e) 6% - lung cancer( 肺癌 ) A B C D E

10 Aerosol particles and the effect on health What effect the pollutants may have on human health and comfort? Gas molecules Cancer Inhalable, <100μm PM100 Allergies PM10 Infection Thoracic <10μm PM2.5 Ultra fine particles Fine particles Coarse particles Respirable, <2.5μm

11 What is the limit value of PM2.5 (annual mean) by WHO? A) 1 μg/m 3 B) 5 μg/m 3 C) 10 μg/m 3 6 D) 25 μg/m 3 5 E) 50 μg/m 3 F) 100 μg/m 3 G) 200 μg/m A B C D E F G 0

12 A decrease in the concentraion of PM2.5 of 10 micro gram/m 3 may affect life expectancy: 6 A) 0 (no effect) B) 0.05 year C) 0.1±0.10 year D) 0.6±0.20 year E) 1.0±0.30 year F) 2.0±0.50 year A B C D E F 0 (Ref. C. Arden Pope et al. Fine-Particulate Air Pollution and Life Expectancy in the United States, The New England Journal of Medicine, 360: (2009) )

13 Human body may be a source of pollutants, like particles, bacteria and microbes? A) Disagree B) Somewhat disagree C) Somewhat agree D) Strongly agree E) Not sure A B C D E

14 Ventilation requirements in Europe Clear minimum requirements: Denmark, France, Sweden and Brussels-Capital Region (BE) A recommendation for minimum ventilation rates: Germany, Italy, Poland, the UK... The indicators for minimum ventilation rates vary from one country to another and are generally different from EU standards (e.g. EN and EN 15251). 14

15 Ventilation standards in dwellings 15

16 How much air is needed for human s breathing? A) 0.05 L/s/person B) 0.1 L/s/person C) 0.5 L/s/person D) 1.0 L/s/person E) 2.0 L/s/person F) 10 L/s/person A B C D E F

17 Ventilation requirements in Norway assessed from three components ralated to pollution from: a. Number of persons b. Building, interior design and installations c. Work or process Ventilation requirement: V = a + b if a + b > c Ventilation requirement: V = c if a + b < c 17

18 Recommanded value in Norwegian guideline (Kima og luftkvalite på arbeidsplassen - Climate and air quality for work spaces) a = 7-10 l/s per person b = 0,7-2,0 l/s per m 2 floor area Normal building materials without strong odor: 2 l/s per m 2 Materials with proven low emission: 0,7 l/s per m 2 Materials with know high emission or missing assessment: more than 2 l/s per m 2 A safety factor of 1.3 is suggested if no more specific assessments are undertaken. 18

19 Ventilation rates should be based on pollution load from occupants and materials ASHRAE Airflow rate = R p P z + R A A z For single office Vent. rate = 2.5 L/s, p x L/s,m 2 x 20 m 2 = 8.5 L/s, p NS-EN 13779:2007 Ventilation for non-residential buildings Performance requirements for ventilation and room conditioning systems 19

20 European standard EN 15251:2007 q tot = n x q p + A x q B (n=number of occupants, A = floor area) q p is Category I: 10 l/s,pers Category II: 7 l/s,pers Category III: 4 l/s,pers q B is Very low polluting building Low polluting building Non lowpolluting building Category I: 0,5 l/s, m 2 1,0 l/s, m 2 2,0 l/s, m 2 Category II: 0,35 l/s, m 2 0,7 l/s, m 2 1,4 l/s, m 2 Category III: 0,3 l/s, m 2 0,4 l/s, m 2 0,8 l/s, m 2 20

21 Relationships among factors influencing indoor air quality How supply airflow rate with affect air quality? V. outdoors V. C s C s indoors C r C e Ṁ Model room with parameters of indoors and outdoor pollution concentration 21

22 Challenge - mixing of supply airflow and indoor pollutants Ventilation system in a hospital (1899 Robert Boyle & Son) Mixing ventilation in a classroom in 1899 (1899 Robert Boyle & Son) 22

23 Protected (occupied) zone ventilation (POV/PZV) Protected occupied zone ventilation (POV/PZV) is a new ventilation method, which separates the indoor space into sub zones by plane jets to protect occupants from infection of epidemic respiratory disease... (Cao et al. Indoor Air 2011Conference) 23

24 Trends of future ventilation Demand control ventilation/smart ventilation o Motion/precense o CO2 o Noise Local air cleaning: o filtration and o gas phase air cleaning Personalized/protected zone ventilation o better thermal comfort, o better local IAQ and o energy saving 24

25 Conclusions Indoor air may contain a wide range of pollutants generated both indoors and outdoors. Many indoor pollutants may have adverse effects on human health even at low concentration. Ventilation is an effective engineering measure to control indoor air quality. Ventilation/airflow rate should be determined by the needs of occupants and the specific requirements of indoor conditions.

26 Thank you for your attention! Guangyu Cao Department of Energy and Process Engineering, NTNU