Ventilation in residential buildings Indoor air quality Blanca Beato Arribas Senior Research Engineer BSRIA 1 Making buildings better Index • IAQ • Ventilation • Guidelines/Legislation • Exposure limits • What affects indoor air quality at home? • How to measure contaminants 2 Making buildings better Indoor Air Quality Good IAQ : “air with no known contaminants at harmful concentrations” (CIBSE) 3 Making buildings better Ventilation Ventilation is needed to: Good IAQ requires: • Provide fresh air • Low external pollution • Remove pollutants in concentrations a space • Low pollutant • Remove odours emission rates from • Remove heat loads internal sources, including materials • Control humidity • Ventilation: dilute and remove pollutants • Effective ventilation 4 Making buildings better Legislation Regulation or standard Area covered Requirements Size of opening areas for background ventilation and Building regulations Part F1 Provision of adequate fresh air rapid ventilation. Particular extract ventilation rates from kitchens, toilets, etc. Provide adequate air for Building regulations Part J1 combustion devices EH40/2005 Workplace exposure limits Provide adequate fresh air, Limit exposure to various pollutants (HSE) filtration Ensure minimal contamination of HSE Approved Code of Practice L24: Regular maintenance of mechanical systems, including air Workplace health, safety and welfare systems conditioning systems. Air quality guidelines for Europe (WHO, Provide adequate fresh air, Limit exposure to various pollutants 2000) filtration 5 Making buildings better Source:CIBSE Legislation Regulation or standard Area covered Requirements Ambient air and cleaner air Limit exposure to SO and for Europe (EEC Directive 2 suspended particulates 2008/50/EC/2008) BS EN 13986:2002 (Emissions from) wood panels (Emissions from) glued laminated BS EN 14080:2005 timber Selection of materials with low emissions. Regular cleaning. Replacement at the end of BS EN 14342:2005 (Emissions from) parquet flooring life. Provision of adequate fresh or "unpolluted" air (Emissions from) vinyl, laminatm BS EN 14041:2004 and carpetsed and rubber floorings, linoleu (Emissions from) suspended BS EN 13964:2004 ceiling tiles Source:CIBSE 6 Making buildings better 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 7 Making buildings better 8 Making buildings better Ventilation systems in dwellings Background ventilators and intermittent extract fans Passive stack ventilation Continuous mechanical extract (MEV) Continuous mechanical supply and extract with heat recovery (MVHR) 9 Making buildings better 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: 3 – NO2 288 µ g/m 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) 10 Making buildings better 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 11 Making buildings better TLVs Ceiling TWA Concentration(ppm) Time (h) 8h 12 Making buildings better At home Indoor air pollution • 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 Making buildings better Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates 14 Making buildings better 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 15 Making buildings better Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates 16 Making buildings better 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 17 Making buildings better Water vapour VOC Gaseous pollutants Indoor air quality Odours Particulates 18 Making buildings better Gaseous pollutants Pollutant: Gas Source Effects Formula Dizziness, suffocation, Carbon dioxide Combustion, breathing death CO2 Lethal at low Carbon monoxide Combustion concentrations CO Hydrogen sulphide Organic waste Strong odour, irritant H2S Nitrogen dioxide Combustion appliances Lung irritant NO2 Electrical equipment, (motors), UV light Ozone sources Lung irritant O3 Increase risk of lung Radon Building materials, rocks cancer Rn Sulphur dioxide Traffic, combustion Lung irritant SO2 19 Making buildings better 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 20 Making buildings better Radon solutions 21 Making buildings better Carbon monoxide CO • Odourless, colourless gas Sources produced by the incomplete • Gas water heaters combustion of any fossil fuel • Propane heaters and stoves oil, wood or gas • Kerosene space heaters • Charcoal grills • Acts by rendering a person • Gasoline and diesel powered gradually unconscious electric generators • Even short duration high • Cigarette smoke concentration exposures • Propane or gasoline-fuelled forklifts • Unfortunately many people • Gasoline powered concrete saws do not recover from the • Indoor tractor pulls unconscious phase • Any boat with a combustion engine • Spray paint, solvents, degreasers, • "the silent killer" and paint removers 22 Making buildings better Symptoms Prevention CO in the COHb atmosphere in Physiological and subjective blood symptoms • Carbon monoxide alarm mg/m % 3 ppm (%) • Inspect and clean heating system, chimney and flue, every year No appreciable effect, except shortness of breath on vigorous exertion; possible • Inspect the pilot light of gas fireplaces tightness across the forehead; dilation of • Never burn charcoal inside the house 0.007 80 70 10 cutaneous blood vessel • Inspect your furnace and other Shortness of breath on moderate appliances, such as gas ovens, exertion; occasional headache with 0.01 140 120 20 throbbing in temples ranges, and cook tops, for adequate ventilation Decided headache; irritable; easily fatigued; judgement disturbed; possible • Never leave a car, mower, or other 0.02 250 220 30 dizziness; dimness of vision gasoline powered engine in an attached garage, even with the garage door open or in confined areas such 0.035- 400- 350- Headache, confusion; collapse fainting on 0.052 600 520 40-50 exertion as a basement Unconsciousness; intermittent convulsion; 0.080- 900- 800- respiratory failure, death if exposure is 0.122 1400 1220 60-70 ling continued 0.195 2200 1950 80 Rapidly fatal Source: WHO 23 Making buildings better Sulphur dioxide SO2 • Colourless, highly reactive gas Sources with a characteristic, irritant • Fossil fuel combustion at pungent odour. 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 24 Making buildings better Sulphur dioxide SO2 Effects on health • Short term exposure to high enough • 8 hour TWA : 0.5ppm (1.3 levels of SO2 can be life mg/m3) STEL (15 mins) : 1.0 threatening. ppm (2.7. mg/m3)(Europe) • Burning sensation in the nose and throat • 8 hour TWA 2 ppm (5 mg/m3) , • Difficulty breathing, including STEL (15 mins) :5 ppm changes in the body’s ability to take (13 mg/m3) STEL (CDC) 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 25 Making buildings better Carbon dioxide CO2 ppm % Symptoms 1000 0.1 Concentration problems 5000 0.5 Normal International safety limit ( HSE, OSHA) 10000 1.0 Rate of breathing increases 15000 1.5 Normal Short term exposure limit ( HSE, OSHA) Breathing increases 50% of normal rate. Tiredness and headaches if exposed for several 20000 2.0 hours Breathing at twice normal rate. Dizziness, increased heart rate and blood pressure. Even 30000 3.0 hearing can be impaired. 40000 to Breathing at four times normal rate. In 30 50000 4 to 5 minutes, signs of poisoning. CO2 can be smelled, tiredness, laboured 50000 to breathing, tinnitus,