Ventilation In Residential Buildings Indoor Air Quality

Transcript

Ventilation in residential buildings Indoor air quality Blanca Beato Arribas Senior Research Engineer BSRIA Making buildings better 1 Index • • • • • IAQ Ventilation Guidelines/Legislation Exposure limits What affects indoor air quality at home? • How to measure contaminants Making buildings better 2 Indoor Air Quality Good IAQ : “air with no known contaminants at harmful concentrations” Making buildings better (CIBSE) 3 Ventilation Ventilation is needed to: • Provide fresh air • Remove pollutants in a space • Remove odours • Remove heat loads • Control humidity Making buildings better Good IAQ requires: • Low external pollution concentrations • Low pollutant emission rates from internal sources, including materials • Ventilation: dilute and remove pollutants • Effective ventilation 4 Legislation Regulation or standard Area covered Requirements Building regulations Part F1 Provision of adequate fresh air Size of opening areas for background ventilation and rapid ventilation. Particular extract ventilation rates from kitchens, toilets, etc. Building regulations Part J1 Provide adequate air for combustion devices EH40/2005 Workplace exposure limits (HSE) Limit exposure to various pollutants Provide adequate fresh air, filtration HSE Approved Code of Practice L24: Workplace health, safety and welfare Ensure minimal contamination of mechanical systems, including air conditioning systems. Regular maintenance of systems Air quality guidelines for Europe (WHO, 2000) Limit exposure to various pollutants Provide adequate fresh air, filtration Making buildings better 5 Legislation Regulation or standard Area covered Ambient air and cleaner air for Europe (EEC Directive 2008/50/EC/2008) Limit exposure to SO2 and suspended particulates BS EN 13986:2002 (Emissions from) wood panels BS EN 14080:2005 (Emissions from) glued laminated timber BS EN 14342:2005 (Emissions from) parquet flooring BS EN 14041:2004 (Emissions from) vinyl, laminatm and carpetsed and rubber floorings, linoleu BS EN 13964:2004 (Emissions from) suspended ceiling tiles Requirements Selection of materials with low emissions. Regular cleaning. Replacement at the end of life. Provision of adequate fresh or "unpolluted" air Source:CIBSE Making buildings better 6 Legislation • Legal requirements: – 1. There shall be adequate means of ventilation provided for people in the building – 2. Fixed systems of mechanical ventilation and associated controls must be commissioned by testing and adjusting as necessary to meet the above objective Making buildings better 7 Making buildings better 8 Ventilation systems in dwellings Background ventilators and intermittent extract fans Continuous mechanical extract (MEV) Making buildings better Passive stack ventilation Continuous mechanical supply and extract with heat recovery (MVHR) 9 Approved document F. Appendix A • It sets out the levels of moisture and pollutants in buildings • For dwellings: – There should be no visible mould – Exposure to the following contaminants should not exceed: – NO2 288 µ g/m3 150 ppb- 1 hour average 40 µg /m3 long term average – CO 100 mg/m3 90 ppm 15 min average 60 mg/m3 50 ppm 30 min average 30 mg/m3 25 ppm 1 hour average time 10 mg/m3 10 ppm 8 hours average time – TVOC (Total Volatile organic compounds) 300 µg/m3 average over 8 hours – Body odours- supply rate of 3.5l/s per person (ASHRAE) Making buildings better 10 TLV Threshold limit value • Guidelines regarding safe levels of exposure at work • Maximum average airborne concentration of a hazardous material to which healthy adult workers can be exposed to: – 8 hours a day – 40 hour week – Working lifetime Making buildings better 11 Concentration (ppm) TLVs Ceiling TWA Time (h) Making buildings better 8h 12 At home Indoor air pollution • • • • • • • • • • • • • • Making buildings better Cigarette smoke Panelling Fireplace orf wood stove Gas stove and/or cooking Paints and varnishes Carpets Moulds or fungi Stored paints, fuels, garden chemicals Car fumes Cleaning products Pets Humans Soil gases Outdoor air 13 Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates Making buildings better 14 Water vapour • Washing, cooking… – Breathing (0.2 l/hour per person) – Shower 1.5 l of water vapour • Water vapour is not a pollutant • Moulds produce spores that float in the air, land on damp surfaces, and grow. • Sneezing, red eyes, skin rashes, asthma attacks. • „The key to mould control is moisture control Making buildings better 15 Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates Making buildings better 16 Odours • Sources: – Some contaminants – Cooking processes – WC, sinks, waste drains • Fanger quantified odour emissions – One “olf” is the rate at which 1 human adult, who is wearing deodorant but not perfume, takes 0.7 baths per day, changes his or her underwear every day, and is resting at a comfortable air temperature, emits air pollutants – Adult exercising 3 olf – Low polluting building 0.1 old /m2 • Relationship between PPD and olf Making buildings better 17 Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates Making buildings better 18 Gaseous pollutants Pollutant: Gas Effects Dizziness, suffocation, Carbon dioxide Combustion, breathing death Lethal at low Carbon monoxide Combustion concentrations Formula Hydrogen sulphide Organic waste Strong odour, irritant H2S NO2 Radon Combustion appliances Lung irritant Electrical equipment, (motors), UV light sources Lung irritant Increase risk of lung Building materials, rocks cancer Sulphur dioxide Traffic, combustion SO2 Nitrogen dioxide Ozone Source Making buildings better Lung irritant CO2 CO O3 Rn 19 Radon Rn • Over 1,100 deaths from lung cancer / year in the UK • Radioactive dust in the air • The dust is trapped in our airways and emits radiation that damages our lungs http://www.ukradon.org/information/ukmaps/englandwal es Making buildings better 20 Radon solutions Making buildings better 21 Carbon monoxide CO • Odourless, colourless gas produced by the incomplete combustion of any fossil fuel oil, wood or gas • Acts by rendering a person gradually unconscious • Even short duration high concentration exposures • Unfortunately many people do not recover from the unconscious phase • "the silent killer" Making buildings better Sources • Gas water heaters • Propane heaters and stoves • Kerosene space heaters • Charcoal grills • Gasoline and diesel powered electric generators • Cigarette smoke • Propane or gasoline-fuelled forklifts • Gasoline powered concrete saws • Indoor tractor pulls • Any boat with a combustion engine • Spray paint, solvents, degreasers, and paint removers 22 Symptoms CO in the atmosphere % 0.007 0.01 mg/m 3 80 COHb in blood ppm 70 140 120 Physiological and subjective symptoms (%) 10 No appreciable effect, except shortness of breath on vigorous exertion; possible tightness across the forehead; dilation of cutaneous blood vessel 20 Shortness of breath on moderate exertion; occasional headache with throbbing in temples Decided headache; irritable; easily fatigued; judgement disturbed; possible dizziness; dimness of vision 0.02 250 220 30 0.0350.052 400600 350520 40-50 Headache, confusion; collapse fainting on exertion 0.0800.122 9001400 8001220 60-70 Unconsciousness; intermittent convulsion; respiratory failure, death if exposure is ling continued 0.195 2200 1950 80 Prevention • • • • • • Carbon monoxide alarm Inspect and clean heating system, chimney and flue, every year Inspect the pilot light of gas fireplaces Never burn charcoal inside the house Inspect your furnace and other appliances, such as gas ovens, ranges, and cook tops, for adequate ventilation Never leave a car, mower, or other gasoline powered engine in an attached garage, even with the garage door open or in confined areas such as a basement Rapidly fatal Source: WHO Making buildings better 23 Sulphur dioxide SO2 • Colourless, highly reactive gas with a characteristic, irritant pungent odour. Sources • Fossil fuel combustion at power plants • Tobacco smoke • Inadequately vented gas appliances, oil furnaces, and kerosene heaters, wood or coal stoves • Automobile exhaust, malfunctioning chimneys Sulphur Dioxide Pollution across East and Southeast Iceland September 26, 2014 10:32 ICELAND REVIEW ON LINE Making buildings better 24 Sulphur dioxide SO2 Effects on health • Short term exposure to high enough levels of SO2 can be life threatening. • Burning sensation in the nose and throat • Difficulty breathing, including changes in the body’s ability to take a breath • Long term exposure can cause changes in lung function and aggravate existing heart disease • Asthmatics may be sensitive to changes in respiratory effects due to SO2 exposure at even low concentrations Making buildings better • 8 hour TWA : 0.5ppm (1.3 mg/m3) STEL (15 mins) : 1.0 ppm (2.7. mg/m3)(Europe) • 8 hour TWA 2 ppm (5 mg/m3) , STEL (15 mins) :5 ppm (13 mg/m3) STEL (CDC) 25 Carbon dioxide CO2 ppm 1000 5000 10000 15000 20000 30000 40000 to 50000 % 0.1 0.5 1.0 1.5 Symptoms Concentration problems Normal International safety limit ( HSE, OSHA) Rate of breathing increases Normal Short term exposure limit ( HSE, OSHA) Breathing increases 50% of normal rate. Tiredness and headaches if exposed for several 2.0 hours Breathing at twice normal rate. Dizziness, increased heart rate and blood pressure. Even 3.0 hearing can be impaired. Breathing at four times normal rate. In 30 4 to 5 minutes, signs of poisoning. CO2 can be smelled, tiredness, laboured breathing, tinnitus, impaired vision, confusion in 5 to 10 a few minutes, unconsciousness. 50000 to 100000 100000 to Making buildings better 1000000 10 to 100 Unconsciousness, suffocation. 26 Contaminant concentration (1) 𝑄𝑡 𝑞 −𝑉𝑝 𝐶 = 𝐵𝐺 + . 1 − 𝑒 . 106 𝑄 Where: • C is the concentration of contaminant (ppm) • BG is the background concentration of contaminant • q is the generation rate m3.hr-1 • Q is the ventilation rate m3/h-1 • Vp is the volume per person m3 • T is the time for occupancy (hr) Ref: BSRIA TN 12 94.1 Making buildings better 27 Contaminant concentration (2) Making buildings better 28 Contaminant concentration (2) • • • • Supply (fresh air) into the room is not always constant because… Air pressure is not constant – From 5 Pa-gentle breeze to 90 Pa-strong breeze – Negative pressure: -5 Pa to 110 Pa The façade is not uniform; gaps in a building are difficult to identify etc Contaminant release into a room is not constant • The release rate of CO2 is known, the release rate of VOC, CO, SO2, Radon from the ground etc, is not easy to determine. • Depends on age ( of the carpet) , tasks of the day, smoking, cleaning etc… Behaviour is not constant: i.e. if we are painting/cleaning, we open the window… • Very difficult to pre-calculate contaminant concentration in a home! Making buildings better 29 Water vapour Gaseous pollutants Indoor air quality Odours Particulates Making buildings better 30 What are VOC? Sources • Carbon-based chemicals that easily evaporate at room temperature • Building Materials: carpets, paints, adhesives, varnishes • Home and Personal Care Products: Cosmetics, cleaning products, cars • Behaviours: cooking, drycleaning, smoking… Making buildings better 31 VOC-health effects • • • • • • • • • How much is in the air, how long and how often a person breathes it in Asthma: different exposures than occupational exposures to VOCs. Each chemical has its own toxicity Short-Term (Acute) to high levels of VOCs Eye, nose and throat irritation Headaches Nausea / Vomiting Dizziness Worsening of asthma symptoms Making buildings better • • • • • • Long-Term (Chronic) to high levels of VOCs Increased risk of: Cancer Liver damage Kidney damage Central Nervous System damage 32 Pollutant: VOC Source Acetone Paint, nail polish, cigarette smoke, household chemical products Benzene Solvents, fuel combustion, smoke, water and soil contamination Ethylene glycol Formaldehyde Methylene chloride/ Dichloromethane Effects Formula Irritant. At high concentrations can (CH₃)₂CO 1,000 ppm harm the nervous system. (2,400 Headache, nausea, dizziness, mg/m3) confusion, unconsciousness. TWA Carcinogen C6H6 Automotive antifreeze, Eye and respiratory tract irritation. ballpoint pens, solvents, Systemic toxicity if ingested paints, plastics, films, cosmetics Formol, disinfectant Carcinogen, strong irritant Paint stripping, metal cleaning adhesives, solvents TWA Carcinogen, mental confusion, nausea and headache. Eye and respiratory tract irritation. Skin irritation or chemical burns. 1 ppm TWA 5 ppm STEL C2H6O2 100 mg/m3 CH2O CH2Cl2 0.75 ppm TWA, 2 ppm STEL TWA 25 ppm ST 125 ppm Sources: CIBSE, CDC Making buildings better 33 Pollutant: VOC Source Effects Formula TWA Tetraclhloroethyl ene Solvents i.e dry cleaning Possible carcinogen C2Cl4 TWA 100 ppm Toluene Solvents i.e paints Tiredness, confusion, weakness, unconsciousness, and even death C7H8 Xylene Fingernail polish, Glues/adhesives Lacquers, Octane booster in gasoline ,Paints Paint thinners Irritant, carcinogen C4H6 1,3butadiene Cigarette smoke, exhaust fumes TWA 100 ppm ST 150 ppm Nose, throat and skin irritant, C6H4(CH3)2 TWA 100 nausea, unconsciousness, embryo ppm (435 toxicity mg/m3) ST 150 ppm (655 TWA 1 ppm ST 5 ppm Sources: CIBSE CDC Making buildings better 34 • Solvent Emissions Directive (1999/13/EC) • Paint Products Directive (2004/42/EC) limitation of emissions of volatile organic compounds due to the use of organic solvents in certain paints and varnishes and vehicle refinishing products and amending Directive 1999/13/EC (Defra) Making buildings better 35 Water vapour VOC Gaseous pollutants Indoor air quality Odours Making buildings better 36 Particulates • Fine particles released by occupants generally during combustion, or produced by external sources: – Clothing, carpets, wall board, aerosol, sprays, dust-mites, insects, and moulds, asbestos, tobacco. – Lung irritation, bronchial asthma and allergic rhinitis Making buildings better Particulates from pollution mixing with clouds above the US (NASA) 37 Pollutant Type Source Effects Particles Combustion appliances, Non aerosol sprays, bio clothing, carpets, wallboard Allergen, bronchial asthma and allergic rhinitis. May aggravate eczema Particles Bio Making buildings better Humans, pets, moulds, plants Allergen, bronchial asthma and allergic rhinitis. 38 Instrumentation used • Measure the dominant pollutants, CO, CO2, VOC, etc • Measure relevant contaminants i.e asbestos, Radon • TVOC-Total Volatile organic compounds VOC Temperature, humidity CO2 Making buildings better RH CO, CO2 Particulates 39 Thank you Any questions? Source:www.salem-news.com Making buildings better 40