FSHB. 8 lectures + 8 seminars. 5 lectures + 5 seminars. Doc. Ing. Václav Kupilík, CSc. Ing. Marek Pokorný, Ph.D. Ing. arch.

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1 FSHB FIRE SAFETY HEALTHY BUILDINGS 8 lectures + 8 seminars Doc. Ing. Václav Kupilík, CSc. Ing. Marek Pokorný, Ph.D. Ing. arch. Petr Hejtmánek 5 lectures + 5 seminars Doc. Ing. Martin Jiránek, CSc. Ing. Martina Zapletalová, Ph.D. Ing. Zuzana Rácová Mgr. Pavla Ryparová

2 HEALTHY BUILDINGS Doc. Ing. Martin Jiránek, CSc. D 2044, jiranek@fsv.cvut.cz

3 REQUIREMENTS FOR GRANTING AN ASSESSMENT TEST During the 5th lecture you will have to take the test SEMINAR WORK On an assigned topic - written form (at least 2 consultations) ATTENDANCE AT LESSONS You should attend at least 70 % of lectures and seminars

4 SEMINAR WORK How is the protection of a building environment against a particular pollutant managed in your country? Required content: Legislation (acts, government regulations, building codes, state subsidy) Limiting concentration, threshold Typical sources of a particular pollutant and typical concentrations inside buildings Measurement (authorization and qualification for measurements, measuring techniques) Protective and remedial measures Form of elaboration: paper work

5 HEALTHY BUILDINGS buildings, where: our health is not deleteriously affected, we feel as happy as possible, we are able to work and rest with the maximum efficiency. In the struggle to build cost-effective buildings, it is easy to forget that the buildings should provide high-quality and healthy interior environments for all users.

6 According to the World Health Organisation up to 30 % of all buildings constructed throughout the world are sick.

7 6 000 of different chemicals and synthetic substances are used for building materials. Some of them emit into indoor air, where they mix with pollutants coming from outdoors or household products into a cocktail that is becoming increasingly difficult to control and analyse.

8 HEALTH RISKS CONNECTED WITH INDOOR ENVIRONMENT All of us face a variety of health risks some of them are unavoidable, some we choose to accept (otherwise they would restrict our ability to lead our lives the way we want) and some are risks we might decide to avoid. Indoor air pollution is one risk that we can do something about.

9 HEALTH RISKS CONNECTED WITH INDOOR ENVIRONMENT People spend approximately percent of their time indoors. Indoor air can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. For many people, the health risks may be greater due to exposure to air pollution indoors than outdoors.

10 SICK BUILDING SYNDROME (SBS) Building occupants complain of symptoms associated with acute discomfort, e.g., headache; eye, nose, or throat irritation; dizziness, nausea, etc. The cause of the symptoms is not known Most of the complaints disappear soon after leaving the building

11 BUILDING RELATED ILLNESS (BRI) Building occupants complain of symptoms such as cough, chest tightness, fever, muscle aches, etc. The symptoms can be clinically defined and have clearly identifiable causes. Complainants may require prolonged recovery times after leaving the building.

12 PRINCIPLES OF HEALTHY BUILDINGS A building site shall be geologically undisturbed. Residential homes are best located away from industrial centres and main traffic routes. Housing shall be developed in a decentralized and loose manner interlaced with sufficient green space. Housing shall be personalized, in harmony with nature, fit for human habitation and family oriented.

13 PRINCIPLES OF HEALTHY BUILDINGS Natural building materials of plants or animals origin shall be used (wood, straw, reed, hemp, cork, sheep wool etc.). Straw

14 Fibreboards formed by wood fibres Cork boards cork bark is harvested from the cork oak tree, no chemicals or additives are used in the manufacture sustainable and renewable thermal and sound insulation

15 Hemp Shive hemp fibre waste Sheep wool

16 PRINCIPLES OF HEALTHY BUILDINGS Walls, floors and ceilings shall be diffusible and hygroscopic. Indoor air humidity shall be regulated naturally. The total moisture content of a new building shall be low and dry out quickly. Harmonic measures, proportions and shapes need to be taken into consideration. The production, installation and disposal of building materials shall not contribute to environmental pollution and high energy costs. Building activities shall not contribute to the exploitation of nonrenewable and rare resources.

17 PRINCIPLES OF HEALTHY BUILDINGS An appropriate balance of thermal insulation and heat retention is needed. A heating system shall use as much passive heat sources as possible.

18 COMMERCIAL BENEFITS OF GOOD INDOOR ENVIRONMENT attracting and maintaining high quality workers improved organisational image increased individual productivity reduced illness and absenteeism operational and maintenance cost savings

19 INDOOR ENVIRONMENT QUALITY Indoor environmental quality is a generic term used to describe the attributes of enclosed spaces that affect a person's health, well-being and comfort. Indoor environment is characterised by: physical factors, such as ambient temperature, humidity and ventilation rates, air pollutant factors, such as pollutant levels and exposure times, human factors, such as occupant health status, individual sensitivity and personal control.

20 CONSTITUENTS OF INDOOR ENVIRONMENT Radionuclides Radium, radon and its decay products EMF Electric. appliances, telecommunication Negative and positive ions in indoor air Static electricity caused when certain materials are rubbed against each other Toxic chemicals (VOCs, HFRs, ) Temperature and humidity of indoor air Odours Bad smell, sweet smell Microbial contaminants Bacteria, molds, pollens, dust mites, saliva, ) Illumination Light falling on working area Acoustics Noise and vibration Psychic strain Building dimensions, shape, colours, air movement, other people Aerosols Asbestos, man-made mineral fibres

21 CONSTITUENTS OF INDOOR ENVIRONMENT Toxic chemicals Volatile organic compounds VOCs Benzene Toluene Xylene Vinyl chloride Formaldehyde Styrene HFRs Sources of VOCs Plastics Cosmetics Composites Tobacco smoke Adhesives Vinyl floors Paints Air fresheners Detergents Pressed wood Wood preservatives Carpets Disinfectants VOCs evaporate from building materials and some of them can pose risks to health (mainly irritating and carcinogenic effects).

22 CONSTITUENTS OF INDOOR ENVIRONMENT Mineral fibres Natural fibres (asbestos) asbestos cement roofing and cladding sheets and pipes, textured coatings, floor tiles, sprayed coatings as fire insulation on steel structures, asbestos insulation boards, loose asbestos thermal insulation, etc. Man-made mineral fibres (rock, ceramic and glass wool) Inhaled fibres deposit in lungs. The higher risk is associated with respirable fibres = fine fibres of diameter less than 0,25 μm. Health effects pulmonary fibrosis asbestosis lung cancer, skin and eye irritations, irritation of the upper respiratory tract.

23 CONSTITUENTS OF INDOOR ENVIRONMENT Natural radionuclides Radium-226 found in some building materials (clinker or cinder concrete), is responsible for external irradiation of occupiers by gamma radiation. Radon (radioactive gas) and its decay products (metal ions) penetrate to houses from the subsoil. Inhalation of radon and its decay products can cause lung cancer.

24 CONSTITUENTS OF INDOOR ENVIRONMENT Microbes Moulds, bacteria, dust mites, pollens, animal dander, saliva. Moulds and fungi are usually associated with increased dampness, surface condensation, etc. The use of carpets and other dust-collecting agents increases the level of bacteria, molds and dust mites. Bacteria Legionella pneumophila can be produced by showers, humidifiers, cooling towers and taps. Health effects dust mites are responsible for allergy and asthma, many mycotoxins (toxins made by moulds) are potent carcinogens

25 CONSTITUENTS OF INDOOR ENVIRONMENT Heavy metals mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr) and lead (Pb) Sources Cr - old chromium based paints, Pb - polluted outdoor air due to combustion of leaded petrol, lead pipes in domestic water systems and lead containing paints, Hg paints, dental fillings, cosmetics, As wood preservatives, paints, Cd batteries, coatings Chromium can act as allergen and carcinogen, exposure to lead is directly associated with defects in mental development and mercury can permanently poison many body enzymes.

26 CONSTITUENTS OF INDOOR ENVIRONMENT Electromagnetic field Extremely low frequency (ELF) field (up to 300Hz): electricity power supply and all electrical appliances Intermediate frequency (IF) field (300 Hz to 10 MHz): computer screens and security systems Radiofrequency (RF) fields (10 MHz to 300 GHz) radio, television and radar transmitters and resonators, mobile phones and their base stations and microwave ovens Health effects depend on the field intensity (frequency and energy) and exposition time. The greatest influence was observed on genitals and nervous system. Radiowaves have heating effect.

27 CONSTITUENTS OF INDOOR ENVIRONMENT Negative and positive ions in fresh country air 2,000-4,000 negative ions/cm 3 in the vicinity of oceans, rivers and waterfalls over 100,000 negative ions/cm 3 in the polluted air in the city the level is far below 100 ions/cm 3 HVAC systems, dust particles and reinforced concrete structures reduce the amount of negative ions Negative ions cause dust, pollen, mold spores, pet dander, etc. to clump together and drop out of the air. Negative ions have positive effects on people - suppress serotonin levels, reduce blood pressure, etc. Positive ions have negative effects on people increase blood pressure, etc.

28 CONSTITUENTS OF INDOOR ENVIRONMENT Static electricity buildup of electric charge on the surface of objects, where it remains until it either bleed off to ground or is discharged static charge will only form when two solid, liquid or gaseous matters are in contact and at least one of the matters has a high resistance to electrical flow (an electrical insulator) discharge of static electricity (electrical spark) may ignite explosive mixtures (finely powdered substances or low conductivity flammable vapours) the voltages encountered may be as high as 15,000 or even 20,000 volts, but the discharge energy is very low to cause health problems Many semiconductor devices used in electronics are extremely sensitive to the presence of static electricity and can be damaged by a static discharge.

29 CONSTITUENTS OF INDOOR ENVIRONMENT Acoustic conditions An acoustically correct environment increases the overall comfort level of a space. Noise comfort has direct influence on health and safety of those who live, work and play within buildings. Occupants in a noisy space can feel irritable, distracted, anxious, hostile and annoyed. Noise discomfort decreases the productivity of employees. Health problems associated with noise exposure include hearing loss, headaches, tinnitus, high blood pressure, heart problems, etc.

30 CONSTITUENTS OF INDOOR ENVIRONMENT Lighting conditions Light can influence human health, physiology, mood and behaviour. Biological effects of light depend on the intensity, spectrum and timing of the light exposure. Occupant perception of luminous environment is affected by: luminance levels and their uniformity access to daylight and views glare levels colour temperature personal control visual appeal of interior design People in western countries have very low daily light exposure, which may lead to increased breast cancer risk or reduced immune function.

31 CONSTITUENTS OF INDOOR ENVIRONMENT Thermal comfort Thermal comfort refers to a condition of mind which expresses satisfaction with the thermal environment. A range of environmental and human factors need to be considered in order to determine what will make people feel comfortable. These factors include: indoor air temperature (spatial and temporal stability) indoor air relative humidity air velocity thermal gradients personal control occupant factors, such as clothing type, level of activity, age, sex, etc.

32 SOURCES OF POLLUTANTS IN INDOOR ENVIRONMENT Human being and its activity (water vapour, CO 2, odours, products of tobacco smoking, etc.) Building materials (gamma radiation, asbestos and other mineral fibres, heavy metals, dust, VOCs styrene, formaldehyde etc.) Surface treatments paints, flooring (VOCs, odours, heavy metals, HFRs, phthalate, etc.) Furnishing - furniture (odours, HFRs, VOCs, etc.)

33 SOURCES OF POLLUTANTS IN INDOOR ENVIRONMENT Electrical devices (HFRs, electromagnetic radiation) Detergents and cosmetics (odours, phthalate, etc.) Pets (aerosols, allergens, microbes, mites, etc.) Food (PCB, heavy metals, pesticides, dioxins, microbes, etc.) External environment (combustion products, dust, odours, noise, vibrations, electromagnetic radiation, ionising radiation, sulphur and nitrogen oxides, etc.) Subsoil (radon, thoron)

34 FACTORS AFFECTING DOSE AND EXPOSURE FROM INDOOR POLLUTANTS Form and composition of applied materials (content of VOCs, radionuclides, fine fibres, etc.) Position within the building (internal or external, exposed or concealed) Degree of degradation (normal weathering, abrasion, corrosion, etc.) Ventilation of the building (air exchange rate) Lifestyle of occupiers (periods of occupation)

35 REMEDIATION PROCEDURE Identification of the pollutant, determination of sources Measurement of the pollutant concentration (in indoor air, domestic water, etc.) Comparison of the measured concentration with the limiting concentration Estimation of the possible health effects Cost benefit analysis in order to come to a realistic view on the appropriateness of remediation Selection of remedial measures (removal, sealing, ventilation, filtration, etc.) Advice on the disposal of removed materials

36 Source control PRINCIPLES OF REMEDIATION Source removal, sealing or adjusting is usually the most effective way to improve indoor air quality Increasing ventilation rates Local exhaust ventilation or central HVAC systems should be operated at required rates, increasing ventilation can increase energy costs Air cleaning Air filters have certain limitations small particles are not effectively captured, relatively high operation costs, frequent replacement of filters

37 RADON PREVENTIVE MEASURES PROTECTION OF NEW BUILDINGS AGAINST RADON FROM THE SOIL International Atomic Energy Agency

38 RADON ORIGIN, HEALTH EFFECT Uranium Uran-238 Rádium-226 Radium a α Radon-222 a Lead Olovo-214 α - Polonium-214 Radon Bismuth Polonium- 214 a α Bismut-214 Polonium b β b β Lead Olovo Radon daughters 218 Po, 214 Pb, 214 Bi a 214 Po give rise to cca 15% of lung cancers. In the Czech Republic they are responsible for cca 900 cases of lung cancers per year. Bismuth Polonium- 210 Polonium-210 a α Bismut-210 a α βb b β Lead Olovo Additional risk of lung cancer increases by 16% per 100 Bq/m 3 (Darby S. et.al.).

39 REFERENCE LEVELS IN EU COUNTRIES WHO proposes a reference level 100 Bq/m 3. If this level cannot be reached, the chosen level should not exceed 300 Bq/m 3.

40 1. RADON SOURCES Inspection chamber Untight pipe penetrations Cracks Drain pipes Wall floor joints Ground under and /or around the building Building materials Domestic water

41 2. RADON RISK AREAS Mapping can be based on: Indoor radon data areas are identified by % of houses with indoor radon concentration above the reference level 200 Bq/m 3, for example: < 1 % low risk area 1 10 % medium risk area > 10 % high risk area Geological data areas are classified with the help of measured soil gas radon concentration and soil permeability

42 2. RADON RISK AREAS Example from CZ - classification into risk areas based on geological data Soil gas radon concentration and soil permeability are measured directly on a building site. Radon risk category is determined according to the following table. Radon risk Soil gas radon concentration (kbq/m 3 ) high > 100 > 70 > 30 vysoké High vysoký risk riziko index Medium střední riziko index risk Low/Medium přechodná oblast risk Low nízké nízký riziko index risk medium low < 30 < 20 < 10 Soil permeability low medium high

43 2. RADON RISK AREAS Example from UK - classification into risk areas based on combination of indoor radon data and geological data The mapping database holds risk data by postcode. Indicative maps based upon 1km grid directly show the type of protection none, basic, full.

44 3. GENERAL PRINCIPLES OF PREVENTION 3.1 Separating a building from the soil Building on pillars Building on crawl spaces

45 3. GENERAL PRINCIPLES OF PREVENTION 3.2 Ensuring air-tightness of the substructure Radon barrier material placed over the entire surfaces of walls and floors in contact with the soil This approach is not effective in existing houses!!!

46 3. GENERAL PRINCIPLES OF PREVENTION 3.3 Changing the pressure difference between the soil and the house by soil or air gaps depressurization Fan generating underpressure under the house or within the air gap is installed if natural draught is not sufficient.

47 3. GENERAL PRINCIPLES OF PREVENTION 3.4 Diluting indoor concentration by increased ventilation Efficient ventilation systems are: mechanical exhaust air ventilation with outdoor air inlets mechanical supply and exhaust air ventilation with heat recovery

48 3. GENERAL PRINCIPLES OF PREVENTION 3.5 Combining radon-proof insulation + subslab depressurization Radon-proof insulation Drainage layer of coarse gravel Roof fan or rotating cowl to improve the draught Vertical exhaust PVC pipe Interconnecting PVC pipe Perforated flexible pipes - Floor layers - Radon-proof membrane - Bonding primer or geotextile - Blinding concrete - Geotextile - Coarse gravel with perforated pipes - Subsoil

49 3. GENERAL PRINCIPLES OF PREVENTION 3.6 Combining radon-proof insulation + air gap depressurization Plastic foil with dimples forming an air gap Roof fan or rotating cowl to improve the draught Vertical exhaust PVC pipe Vented air gap between concrete slab and radonproof insulation at a height from 10 to 20 mm - Floor layers - Radon-proof membrane - Cement screed - Plastic membrane with dimples - Blinding concrete - Subsoil

50 3. GENERAL PRINCIPLES OF PREVENTION The type and the degree of protection depends on the radon risk of the building site and other factors influencing the design. Radon risk Measures Principle of protection Low Traditional design No special protection is required. No open connections from the building to the ground. Medium High Standard (basic) radon protection Radon-protecting design Increased (full) radon protection Radon-proof design The basic measure is an impermeable substructure: reinforced concrete radon-proof insulation Impermeable substructure is usually combined with: sub-slab depressurization air gaps ventilation

51 4. PRINCIPLES OF THE CZECH PREVENTION The type and the degree of protection depends on: the radon index of the building site (low, medium, high) location of habitable rooms other initial conditions (presence of a highly permeable sub- floor layer, sub-floor heating etc.) Radon index Low Medium or high Principle of protection No special protection is required. Waterproof insulation or waterproof reinforced concrete construction Protection is required in dependence on the type of a building and type of ventilation

52 4. PRINCIPLES OF THE CZECH PREVENTION Houses with naturally ventilated habitable rooms on the floors in direct contact with the soil Protection = radon-proof insulation Combination with soil or air gap ventilation must be applied, if: Soil gas radon concentration exceeds: 60 kbq/m 3 in highly permeable soils, 140 kbq/m 3 in soils with medium permeability, 200 kbq/m 3 in soils with low permeability. Highly permeable gravel layer is placed under the house Floors resting on the soil are equipped with under-floor heating

53 4. PRINCIPLES OF THE CZECH PREVENTION Houses with habitable rooms located on the upper floors Protection = water-proof insulation or waterproof reinforced concrete construction Conditions that must be satisfied: a reliable ventilation rate is ensured in any place of the contact floor the ceiling above the contact floor is airtight with sealed services penetrations the entrances to the contact floor from the other floors are ensured with doors of a good air-tightness and equipped with a door closer

54 4. PRINCIPLES OF THE CZECH PREVENTION Houses equipped with mechanical ventilation (in all habitable rooms of the contact floor) Protection = water-proof insulation or waterproof reinforced concrete construction Houses on crawl spaces Protection = crawl space ventilation; water-proof or radon-proof courses in the floor above the crawl space applied only under defined conditions

55 5. AIR-TIGHT SUBSTRURE Airtightness is ensured by application of radon proofinsulation (RPI) over the entire surfaces of walls and floors in contact with the soil. RPI fulfils also the function of waterproof insulation it is selected from standard waterproof materials RPI should have verified radon barrier properties Durability of RPI should correspond to the lifetime of the building

56 5.1 Position of RPI in the substructure Above slab application Sub slab application - Floor layers - Protective layer - Radon-proof insulation - Bonding primer or geotextile - Blinding concrete - Leveling layer - Subsoil - Floor layers - Blinding concrete - Protective layer - Radon-proof insulation - Geotextile - Leveling layer - Subsoil

57 5.2 Properties of RPI RPI must withstand predictable deformations and movements of the substrate and foundation construction Tensile strength, elongation, tear resistance and other material and physical parameters must be taken into account when designing radon-proof courses RPI must be resistant to soil corrosion caused primarily by microbiological agents and chemical compounds occurring in the soil

58 5.3 Testing of barrier properties of RPI Reasons for testing Great amount of tanking materials of different chemical composition Difficult selection of membranes with barrier properties against radon Tested quantity Radon diffusion coefficient is a material property that determines diffusive transport it seems to be a convenient parameter for testing of barrier properties

59 5.3 Testing of barrier properties of RPI Principle of the test method Measurement of the radon transport through the tested sample that is placed between the source and receiver containers Using an appropriate mathematical procedure, the radon diffusion coefficient is calculated from the timedependent courses of the radon concentrations measured in the source and receiver containers, and the area and thickness of the tested sample.

60 5.3 Testing of barrier properties of RPI Radon diffusion coefficient should be determined according to the ISO/TS Technical Specification that is currently being drafted. It is expected to be approved and published in 2017.

61 5.4 Summary of radon diffusion coefficient values Measured by the Faculty of Civil Engineering of the Czech Technical University in Prague and National Radiation Protection Institute in Prague

62 5.5 Design of radon-proof insulation Three different approaches are used: 1. Limit for the maximal value of D Applied for example in Ireland (max D = m 2 /s ) 2. Limit for the minimal thickness of the membrane Applied for example in Germany (d 3l) 3. Calculation of the membrane thickness in dependence on the soil and building characteristics Applied for example in Czech Republic, Slovakia, Spain

63 Example from CZ - formula for calculating the thickness of RPI d l.arcsinh α1. l. λ. CS.( Af + C. nv. dif C s radon concentration in the soil gas (Bq/m 3 ) λ..radon decay constant (0,00756 h -1 ) d..thickness of the membrane (m) l.. radon diffusion length in the membrane l = (D/λ) 1/2 (m) D. radon diffusion coefficient in the membrane (m 2 /h) α 1 safety factor A f A w.floor and wall areas in contact with the soil (m 2 ) n ventilation rate (h -1 ) C dif fraction of reference level caused by diffusion (Bq/m 3 ) 5.5 Design of radon-proof insulation A w )

64 5.6 Materials for radon-proof insulation Suitable materials Bitumen membranes based on plastomeric APP or elastomeric SBS bitumen Polymeric flexible membranes made of PVC, PP, LDPE, HDPE, TPO Unsuitable materials Bitumen membranes based on oxidised bitumen All membranes with the reinforcing fabric based on paper boards, rag boards or jute hessian Rubber membranes made of EPDM Cement coatings Bentonite materials

65 5.6 Materials for radon-proof insulation Prohibited materials Bitumen membranes with Al foil barrier properties are formed by AL foil that can be easily damaged, ruptured Plastic membranes with dimples (Delta, Platon, Tefond, etc.) it is almost impossible to create air-tight joints Radon diffusion coefficient (m 2 /s) HDPE dimpled membrane (4,1 ± 0,1) Overlap joint sealed by self adhesive tape (7,4 ± 0,7).10-10

66 5.6 Materials for radon-proof insulation Water-proof materials X Radon-proof materials Water-proof materials are not automatically radonproof Water-proof materials that are permeable for water vapour are also permeable for radon Radon-proof materials are also water-proof

67 5.7 Execution of radon-proof courses RPI should be installed by qualified and experienced personnel Regular supervision of the insulating works should be carried out Prior to the application of RPI, an inspection of the substrate should be carried out RPI, once placed, is to be protected as soon as possible from mechanical damage caused by subsequent construction and finishing works (by covering with a protective geotextile, with plastic panels, with a concrete screed, thermal insulation boards, etc.).

68 5.7 Execution of radon-proof courses All joints and services penetrations must be airtight Joints of self-adhesive membranes should be sealed by torching Radon diffusion coefficient (m 2 /s) SBS modified bitumen membrane Overlap joint sealed by torching Self-adhesive overlap joint (7,1 ± 0,2) (8,6 ± 1,0) , ,

69 5.8 Air-tightness of services penetrations Factors influencing the air-tightness Position of the penetration (corners, wall/floor joints should be avoided) Applicability of details Correct sequence of trades

70 5.8 Air-tightness of services penetrations Examples of inapplicable sealing around pipe penetrations

71 5.9 Thermal protection X radon protection Radon-proof insulation must prevent radon from penetrating through an air gap between perimeter thermal insulation and foundations Elimination of thermal bridges should not result in radon bridges Thermal insulation Internal plaster Head joint free of mortar Perimeter air gap Hollow clay blocks Thermal insulation XPS 80 mm Perimeter air air gap gap Hollow clay blocks Damp-proof membrane (DPM) Section A - A Internal plaster Head joint free of mortar Perimeter air gap Hollow clay blocks Thermal insulation XPS 80 mm

72 5.9 Eliminating radon bridges Interrupting an air gap between perimeter thermal insulation and foundations Hollow clay blocks HDPE corner strip Radonproof membrane Protective fabric Bitumen radonproof membrane Bit. bonding primer Continuous HDPE membrane with airtight joints

73 5.9 Example of eliminating radon bridges in UK Interrupting an air gap in cavity walls (slab on grade) By: Chris Scivyer, BRE, UK

74 5.9 Example of eliminating radon bridges in CZ Single family house ROOM Bq/m 3 BOILER ROOM ROOM Bq/m 3 HALL BATHROOM LIVING ROOM WC Bq/m 3 Average indoor Rn conc. before mitigation: Bq/m 3 KITCHEN BEDROOM Bq/m 3 Soil gas Rn concentration: 5,3 137,6 kbq/m 3 Third quartile: 50,4 kbq/m 3

75 5.9 Example of eliminating radon bridges in CZ Factors responsible for failures Radon transport through the radon bridge in the external walls Radon penetration through joints in the radon-proof insulation and around pipe penetrations

76 5.9 Example of eliminating radon bridges in CZ Eliminating the bridge Removed part of XPS boards Bitumen coating 3 mm Existing waterproofing PVC Ø 60 mm PVC Ø mm Gravel layer Borehole Ø 80 mm Drilled perforated pipe Ø60 mm PU foam

77 5.9 Example of eliminating radon bridges in CZ Trench excavated in the ground PVC 100 mm Fan NPV 190/125 installed 1 m above the terrain PVC 125 mm under the terrain Drilled pipe 60 mm D = 6,0 m Drilled pipe 60 mm D = 3,5 m PVC 100 mm Drilled pipe 60 mm D = 5,0m

78 5.9 Example of eliminating radon bridges in CZ During active ventilation indoor radon concentration decreased to the values below 100 Bq/m 3. Fan in operation lowest speed Fan in operation lowest speed

79 6. SUB-SLAB DEPRESSURIZATION The principle of SSD methods is to change the pressure difference between the soil and the house, i.e. to lower the air pressure in the soil under the house compared to the pressure indoors and to dilute the subsoil radon concentration. The pressure is lowered by means of the natural draft occurring as a result of the stack effect and wind forces, or by a fan.

80 6. SUB-SLAB DEPRESSURIZATION Systems suitable for new buildings Radon sumps Network of flexible perforated pipes inserted into the drainage layer Combination of the above stated measures

81 6. SUB-SLAB DEPRESSURIZATION General design rules The form of soil depressurization depends on: - ratio of underfloor layer and soil permeabilities k d /k s - airtightness of floors - type and geometry of foundations A sump or a perforate pipe must be laid in every subfloor space surrounded by strip foundations. In order to minimize the occurrence of negative side effects (drying and freezing of the subsoil) the distance of a sump or a pipe from perimeter foundations should be at least 0,5 m.

82 6. SUB-SLAB DEPRESSURIZATION General design rules Passive extraction of the soil air using vertical exhaust pipe terminating above the roof should be preferred. Each passive system must enable the supplementary assembly of a fan to increase the system s efficiency. To avoid re-entering of radon into a building, the outlets of the exhaust pipes should be located at least 2 m away from windows, vent holes and inlets of HVAC systems.

83 6.1 Sump systems Sump is a free air space below the building s floor with a volume of at least 10 dm 3 Sump is always created in a drainage layer of coarse gravel One sump is effective over a floor area of approx m 2 Sump should be preferably placed into the centre of the underfloor space If the underfloor space is divided by strip foundations into several compartments, sump must be placed into each compartment.

84 6.1 Sump systems Sump construction Made in situ using bricks with air gaps left between them Preformed plastic components

85 6.1 Sump systems Standby sump system with pipework terminating in the footpath The system is activated when the indoor Rn level exceeds the required value.

86 6.1 Sump systems Examples of sump systems from UK Preformed plastic sump By: Chris Scivyer, BRE, UK

87 6.1 Sump systems Example of a prefabricated sump from Ireland By: Radon Control Systems, IRL

88 6.1 Sump systems Example of a prefabricated sump from Ireland By: Radon Control Systems, IRL

89 6.2 SSD systems with perforated pipes Diameter of perforated pipes: mm for natural ventilation mm for forced ventilation Pipes are placed into a continuous drainage layer with a minimum thickness of 150 mm created from coarse gravel fraction of 16/32 mm. Pipes are laid in every section bordered by the strip foundations. Mutual distance between perforated pipes is around 4 m Perforated pipes ensure better pressure distribution than sumps, therefore they are more convenient for highly permeable soils.

90 6.2 SSD systems with perforated pipes

91 6.2 SSD systems with perforated pipes

92 6.2 SSD systems with perforated pipes

93 6.2 SSD systems with perforated pipes

94 6.2 SSD systems with perforated pipes

95 6.2 SSD systems with perforated pipes Ventilation merely to the perimeter walls is unacceptable

96 6.3 Fans suitable for SSD systems Fans must be able to: transport soil air with a relative humidity from 80 % to 100 % resist the flow of condensed water resist the increased dustiness of the transported air

97 6.3 Fans suitable for SSD systems Types of fans Paddle-wheel fans for longer piping and greater pressure loss Roof fans for longer piping and greater pressure loss Axial fans are not convenient they do not generate sufficient pressure

98 7. AIR GAPS DEPRESSURIZATION The principle of an air gap depressurization is to lower the air pressure in the gap that is provided along walls and floors in contact with soil. The pressure is usually lowered by means of a fan.

99 7. AIR GAPS DEPRESSURIZATION The air gap must be continuous throughout the entire area of the constructions in contact with the soil. Active ventilation is preferred. Active ventilation is executed without any vent holes delivering external air into the gap. Passive ventilation must be always executed using vertical exhaust pipes. Passive ventilation merely to the perimeter walls is unacceptable. Passive ventilation with indoor air is not allowed.

100 7. AIR GAPS DEPRESSURIZATION Air gaps construction Plastic membranes with dimples Corrugated steel, cement-fibre or plastic sheets Preformed plastic components

101 7. AIR GAPS DEPRESSURIZATION An air gap below the radon-proof membrane Exhaust pipe Radonproof membrane Airtight pipe penetration Vent holes Air gap Concrete base

102 7. AIR GAPS DEPRESSURIZATION An air gap above the radon-proof membrane Exhaust pipe Radonproof membrane Air gap Self-adhesive tape Airtight socket joint Collar Airtight joint to the the wall

103 8. HOUSES ON CRAWL SPACES 8.1 Ventilating with outdoor air Optional paddlewheel fan Optional axial fan

104 8. HOUSES ON CRAWL SPACES 8.2 Ventilating with indoor air Paddle-wheel fan Beware of water vapour condensation. Cold surfaces within the crawl space should be thermally insulated. Backflow preventer

105 8. HOUSES ON CRAWL SPACES 8.3 Sealing the ground surface Concrete slab with sealed joints to the walls Polymeric membrane with sealed joints to the walls

106 8. HOUSES ON CRAWL SPACES 8.4 Lowering the air pressure under the sealed ground surface Polymeric membrane with sealed joints to the walls Paddle-wheel fan Drainage pipes

107 8. HOUSES ON CRAWL SPACES 8.5 Sealing the floor above the crawl space In case of suspended timber floors application of radon-proof insulation should not result in unacceptable condensation of water vapour within the floor!!! Radon-proof insulation laid also under the walls

108 8. HOUSES ON CRAWL SPACES 8.6 General principles The entrance to the crawl space is recommended to be located from outside Water and wastewater pipes passing through the crawl space are to be fitted with thermal insulation When ventilating the crawl space with outdoor air, outer walls and the floor above the space must be equipped with thermal insulation When ventilating the crawl space with indoor air, outer walls and the ground surface must be provided with thermal insulation

109 9. VENTILATION MEASURES The principle of ventilation is to dilute radon concentration by increasing the ventilation rate Radon concentration C = J n. Radon supply rate Ventilation rate V Interior air volume

110 9. VENTILATION MEASURES The preference should be given to systems that are balanced (amounts of supply and exhaust air are the same), or to systems creating a slight underpressure. Systems creating overpressure are not recommended in countries with cold climates (condensation problems). The preference should be given to demand controlled ventilation systems that balance indoor air quality and energy savings required amount of fresh air is provided only when it is needed (when the rooms are occupied).

111 9. VENTILATION MEASURES 9.1 Natural ventilation supported by outdoor air inlets Types of outdoor air inlets: Outdoor air inlet Window registers for installation in window frames Wall registers for installation in external walls

112 9. VENTILATION MEASURES Window registers Air flow through the inlets can be adjusted: manually by the owner Flow rate (m3/h) Pressure difference (Pa) Wall registers automatically in dependence on the indoor air humidity Max. air flow rate 35 m3/h Min. air flow rate 5 m3/h Indoor air rel. humidity (%)

113 9. VENTILATION MEASURES Window registers Wall registers Interior side Exterior side

114 9. VENTILATION MEASURES Legend: OVS outdoor air inlet LIVING ROOM HALL KITCHEN ENTRANCE TECH. ROOM

115 9. VENTILATION MEASURES 9.2 Mechanical exhaust air ventilation (hybrid ventilation) with outdoor air inlets Hybrid or exhaust fan Outdoor air inlet Exhaust unit

116 9. VENTILATION MEASURES Exhaust units Exhaust unit with presence detection Humidity senzitive exhaust unit They open only when the ventilation is needed - demand control ventilation.

117 9. VENTILATION MEASURES Fans suitable for exhaust ventilation Fans for several exhaust units Hybrid fans installed at the top of the exhaust pipe create a complementary pressure when the natural draught is not sufficient

118 9. VENTILATION MEASURES Legend: OVS outdoor air inlet OS exhaust fan 1 humidity sensitive exhaust unit LIVING ROOM ENTRANCE CORRIDOR BEDROOM 2 - exhaust unit with presence detection KITCHEN BEDROOM

119 9. VENTILATION MEASURES 9.3 Mechanical supply and exhaust air ventilation Ventilation unit with filters, heat exchanger, preheater and fans. Due to energy costs the ventilation rate should not exceed 1,0 h -1, otherwise supplementary measures (sealing of the substructure) should be adopted.

120 9. VENTILATION MEASURES Legend: VJR ventilation unit with heat recovery LIVING ROOM ENTRANCE BEDROOM CORRIDOR KITCHEN BEDROOM

121 9. VENTILATION MEASURES Exhaust air should not be mixed with supply air!!! Air mixing decreases the effectiveness of ventilation in reducing radon concentration.