Ventilation standards EN15251 and ANSI/ASHRAE 62.1 Professor Bjarne W. Olesen, Ph.D.

Transcription

1 Ventilation standards EN15251 and ANSI/ASHRAE 62.1 Professor Bjarne W. Olesen, Ph.D. Technical University of Denmark

2 Energy consumption for ventilation Exhaust Ventilation air Up to 30% of the total energy consumption in buildings Energy for conditioning the ventilation air

3 CRITERIA FOR INDOOR AIR QUALITY ~VENTILATION RATES COMFORT (Perceived Air Quality) HEALTH PRODUCTIVITY ENERGY

4 INTAKE FOR A PERSON PER DAY 1 kg FOOD 2 kg LIQUID 15 kg AIR

5 Odds Rstio for "cases" Odds ratio for being a case, i.e. children with at least two symptoms of possible three (wheezing, rhinitis, eczema) as a function of ventilation rates, in single family houses. (Bornehag et al., 2003) n= 0.17 n= 0.29 n= 0.38 n= 0.62 Mean values for ventilation rates

6 Figure 1. Adjusted odds ratio of SBS for low outdoor air flow rate in commercial buildings [3]

7 Standard 62.1 Definition: What is Acceptable Indoor Air Quality? Air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction

8 STANDARDS EN Indoor environmental input parameters for design and assessment of energy performance of buildings- addressing indoor air quality, thermal environment, lighting and acoustics ASHRAE 62.1 and Ventilation and indoor air quality CR 1752 Ventilation of buildings-design criteria for the indoor environment EN Ventilation for non-residential buildings - performance requirements for ventilation and room-conditioning systems

9 Indoor pollution sources Human bioeffluents Building materials Furnishing HVAC system Equipment Tobacco smoking Building

10 European Audit Project to Optimise Indoor Air Quality and Energy consumption in Office Buildings Sensory pollution load- perceived air quality Materials and activities Outdoor air Occupants Ventilation system

11 TWO PATHWAYS Ventilation Rate Procedure Prescriptively Based Rates by Space Type Rates by occupants level Indoor Air Quality Procedure Performance Based Concentration Targets Occupant Acceptability Air Cleaning Allowed

12 Analytical procedure Ventilation Rate Health

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14 CEN CR 1752 EN15251 ASHRAE 62.1 Diagram based on studies with Danish subjects (Fanger et.al). Similar results obtained by North-American subjects (Cain et.al.) Similar results obtained with Japanese subjects (Tanabe)

15 Basic required ventilation rates for diluting emissions (bio effluents) from people for different categories Category Expected Percentage Dissatisfied Airflow per person l/s/pers I 15 1O II 20 7 III 30 4 IV > 30 < 4 Adapted persons 2,5 l/s person (Cat. II )

16 Indoor pollution sources Human bioeffluents Building materials Furnishing HVAC system Equipment Tobacco smoking Building

17 Concept for calculation of design ventilation rate People Component Building Component Breathing Zone Outdoor Airflow V bz = R p P z + R s S d + R a A z Minimum l/s/person Number of People Ventilation per Smoker Number of Smokers Building Area Minimum l/s/m²

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19 7 independent studies have measured sensory pollution loads in 120 buildings (olf/m 2 floor) 97 office buildings & assembly halls (previous ETS) 0.23± office buildings (no ETS) 0.11± kindergartens 0.06± schools 0.06± department store 0.15 European standard (EN15251): Very Low-polluting building 0.05 Low-polluting building 0.1 Non-low-polluting building 0.2

20 Basic Ventilation Airflow for building emissions pollutions (l/s/m²) Category Airflow per person l/s/pers. Very low polluting building Low polluting building Non low polluting building I 1O 0,5 1 2 II 7 0,35 0,7 1,4 III 4 0,2 0,4 0,8

21 Low Polluting Building The majority of the materials are low polluting. Low polluting materials are natural traditional materials, such as stone and glass, which are known to be safe with respect to emissions, and materials which fulfil the following requirements: The emission of total volatile organic compounds (TVOC) is below 0.2 mg/m²h. The emission of formaldehyde is below 0.05 mg/m²h. The emission of ammonia is below 0.03 mg/m²h. The emission of carcinogenic compounds (IARC) is below mg/m²h. The material is not odorous (dissatisfaction with the odour is below 15 %).

22 Very Low Polluting Building All of the materials are very low polluting and smoking has never occurred and is not allowed. Very low polluting materials are natural traditional materials, such as stone, glass and metals, which are known to be safe with respect to emissions, and materials which fulfil the following requirements The emission of total volatile organic compounds (TVOC) is below 0.1 mg/m²h. The emission of formaldehyde is below 0.02 mg/m²h. The emission of ammonia is below 0.01 mg/m²h. The emission of carcinogenic compounds (IARC) is below mg/m²h. The material is not odorous (dissatisfaction with the odour is below 10 %).

23 Recommended ventilation rates for non-residential buildings for three categories (EN15251) Type of building or space Category Per person l/s,person Per floor area l/s,m 2 Per person l/s,person Per floor area l/s,m 2 Per person l/s,person Per floor area l/s,m 2 Very low polluted building, revision Low polluted building, revision Non-low polluted building, revision Single office I 5,0 1,5 10,0 2,0 20,0 3,0 II 3,0 1,0 7,0 1,4 14,0 2,1 III 2,0 0,6 4,0 0,8 8,0 1,2 Landscaped office Conference room I 7,5 1,5 15,0 1,7 30,0 2,7 II 4,5 1,0 10,5 1,2 21,0 1,9 III 3,0 0,6 6,0 0,7 12,0 1,1 I 1,0 1,5 2,0 6,0 4,0 7,0 II 0,6 1,0 1,4 4,2 2,8 4,9 III 0,4 0,6 0,8 2,4 1,6 2,8

24 Type of building/ space Single office (cellular office) Occupancy person/m 2 0,1 Category CEN Occupants only l/s person ASH- CEN RAE Rp Additional ventilation for building (add only one) l/s m 2 CEN lowpolluting building CEN Non-lowpolluting building ASH- RAE Ra Total l/s m 2 CEN Low Pol. A 10 1,0 2,0 2 B 2,5 7 0,7 1,4 0,3 1,4 C 4 0,4 0,8 0,8 ASH- RAE 0,55 Landscaped office 0,07 A 10 1,0 2,0 1,7 B 2,5 7 0,7 1,4 0,3 1,2 C 4 0,4 0,8 0,7 0,48 Conference room 0,5 A 10 1,0 2,0 6 B 2,5 7 0,7 1,4 0,3 4,2 C 4 0,4 0,8 2,4 1,55 1 l/s m 2 = 0.2 cfm/ft 2 International Centre for Indoor Environment And Energy

25 Recommended CO 2 concentrations above outside for non-residential buildings for three categories Compared to 650ppm (1000ppm) VERY LOW POLLUTED LOW POLLUTED NON LOW POLLUTED TYPE OF BUILDING CATEGORY ΔCO2 ΔCO2 ΔCO2 ppm ppm ppm SINGLE OFFICE LANDSCAPED OFFICE CONFERENCE ROOM AUDITORIUM Higher Same Lower

26 Adapted or Un-adapted? Bioeffluents (body odor) Adapted need only one third of outside air (~7 l/s to 2.5 L/s) Tobacco smoke (ETS) Only limited adaptation (odor, irritation) Building materials and HVAC systems No adaptation International Centre for Indoor Environment And Energy

27 Adapted or Un-adapted? Conference rooms. Adapted? Classrooms. Adapted? Restaurants. Un-adapted? Department stores. Un-adapted International Centre for Indoor Environment And Energy

28 v Required ventilation rate The total required system ventilation rate is calculated by taking into acount the ventilation effectiveness: Total system ventilation rate = V/ε v

29 Ventilation effectiveness

30 Inhaled Air Quality V eff 1 V eff 1.4 (6)

31 Ventilation effectiveness

32 Air Distribution Configuration Ceiling supply of cool air 1.0 Ceiling supply of warm air and floor return 1.0 Ceiling supply of warm air 15 F (8 C) or more above space temperature and ceiling return. Ceiling supply of warm air less than 15 F (8 C) above space temperature and ceiling return provided that the 150 fpm (0.8 m/s) supply air jet reaches to within 4.5 ft (1.4 m) of floor level. Note: For lower velocity supply air, Ez= 0.8. Floor supply of cool air and ceiling return provided that the 150 fpm (0.8 m/s) supply jet reaches 4.5 ft (1.4 m) or more above the floor. Note: Most underfloor air distribution systems comply with this proviso. Floor supply of cool air and ceiling return, provided low- velocity displacement ventilation achieves unidirectional flow and thermal stratification Floor supply of warm air and floor return 1.0 Floor supply of warm air and ceiling return 0.7 Makeup supply drawn in on the opposite side of the room from the exhaust and/or return Makeup supply drawn in near to the exhaust and/or return location As an alternative to using the above values, Ez may be regarded as equal to air change effectiveness determined in accordance with ASHRAE Standard for all air distribution configurations except unidirectional flow. Ez

33 Energy Efficient Technologies Indoor air quality Reduce loads (pollution sources) Natural ventilation Heat recovery Air distribution (contaminant removal) effectiveness» Personal ventilation Air cleaning Thermal comfort Reduce loads (building shell, solar screen, internal loads) Low Temperature Heating- and High Temperature Cooling Systems Use of building mass (Thermo-Active-Building-Systems (TABS)) Drifting temperatures

34 Only 0.1 % is inhaled International Centre for Indoor Environment And Energy

35 International Centre for Indoor Environment And Energy

36 Round Movable Panel Headset International Centre for Indoor Environment And

37 Smoke visualization How it works... International Centre for Indoor Environment And Ene

38 Full-scale measurements Exposed Polluting International Centre for Indoor Environment And Energy

39 First results... outstanding performance! Ventilation Effectiveness V C C CEN Report CR 1752 (1998) E I C C S S Concentrations: C E exhaust air C S C I supply air breathing zone Mixing ventilation Mixing ventilation Displacement ventilation Personalized ventilation T supply - Vent. effect. T supply - Vent. effect. T supply - Vent. effect. T supply - Vent. effect. T inhal T inhal T inhal T room C - C - C - C - < 0 0,9-1,0 < -5 0,9 <0 1,2-1,4-6 1,2-2, , ,9-1, ,7-0,9-3 1,3-2, ,8 > 0 1 >2 0,2-0,7 0 1,6-3,5 > 5 0,4-0,7 International Centre for Indoor Environment And Ene

40 AIR CLEANING Filters Photocatalytic Oxidation (PCO) Electrostatic Dessicant air cleaners Others International Centre for Indoor Environment And Energy

41 Clean and dirty filters

42 Why do filters pollute? Particle concentration Percentage Dissatisfied International Centre for Indoor Environment And Energy

43 Hypotheses SVOCs sorbed on particles SVOCs in gas phase Oxidized SVOCs Unreacted SVOCs

44 Gas phase air purification technologies Photo-catalytic oxidation (PCO) Ozone oxidation Thermal catalytic oxidation (TCO) Plasma oxidation Botanic filtration Sorption filtration

45 Number of Published Articles Catalytic Oxidation Filtration Ozone Plasma Sorption UVGI Published Year

46 Photo catalytic Oxidation (PCO) Catalyst:TiO 2 UV H 2 O CO 2 Adsorption of contaminants Photocatalytical reaction Desorption of final products

47 Perceived air quality (decipol) Results: Bldg mat, PCs, filters P<0.017 Purifier Off Purifier On 10 5 P< low (35 L/s) intermediate (59 L/s) Outdoor air supply rate

48 Perceived air quality (decipol) Results: Human bio effluents P<<0.001 Purifier Off Purifier On P<< low (12 L/s) intermediate (25 L/s) Outdoor air supply rate

49 PD % PAQ in PD% with and without desiccant rotor P< P< P< without desiccant rotoer with desiccant rotor Conditions: Room volume: 40m 3 Outdoor airflow: 13L/s Outdoor air exchange Rate: /h Room relative humidity: 40% Room temperature: 23ºC Recirculated airflow: 54L/s 0 Carpet Linoleum Human

50 Effect of air cleaning on perceived Air Quality Sources: Peoplebuilding materialsused filters

51 STANDARDS Test methods for assessing the performance of gas-phase air cleaning media and devices for general ventilation - Part 2: Gas phase air cleaning devices (GPACD) (ISO/DIS :2011) ISO/TC 142, Cleaning equipment for air and other gases CEN/TC 195 Air filters for general air cleaning

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53 Chemical Air Cleaning Efficiency

54 Perceived Air Quality Air Cleaning Efficiency

55 Clean Air Delivery Rate

56 Reduction of Ventilation Rate Testing with gas concentrations The building component can be reduced according to the air cleaning efficiency Testing of Perceived Air Quality (PAQ) The total ventilation rate can be reduced according to the PAQ air cleaning efficiency.

57 Destilled water

58 Natural mineral water

59 Performance Ventilation vs performance % (R 2 =0.777; P=0.009) Ventilation rate (L/s per olf)

60 Performance Performance of schoolwork as a function of classroom ventilation 1,4 1,2 1 0,8 0,6 R 2 = Ventilation (L/sp) Doubling ventilation rate ~14.5% higher performance

61 Summertime classroom T in C (NB: Different classes with natural/mechanical ventilation) No AC AC 15 Off Low High Mechanical ventilation

62 Hours/week with windows open (NB: Different classes with natural/mechanical ventilation) No AC AC 0 Off Low High Mechanical ventilation

63 Hours/week with windows open (NB: different classes in winter & summer) Summer Winter 2 0 Low High Ventilation (with no cooling)

64 Analytical calculation of required ventilation Comparable to analytical calculation of cooling loads. No table with cooling loads (W/m 2 ) depending on room type.

65 Ventilation rate Cooling load Parameter Ventilation rate Cooling load Comfort requirement % dissatisfied-odor(paq) % dissatisfied Health- TLV Max. t o, 26 o C Analytical Mass balance Heat balance Outside environment Particles, odors, gases Temperature, solar load, humidity Air cleaning Heat recovery Building materials Emissions/adsorption Heat resistance/heat capacity People Bioeffluents Heat emission Evaporation Internal sources Emissions Heat emission Computers Odors, gases Watts HVAC system Outside air, emissions from components Outside air, Cooled air, heat exchange

66 CONCLUSIONS Air Cleaning as substitute for ventilation must be introduced in standards for required ventilation rates in buildings Test standards for gas phase air cleaners must also include measurements of perceived air quality A certification scheme must be introduced

67 CONCLUSIONS There is no standard which directly specifies requirements for the indoor air quality. Instead it is indirectly achieved by specifying a required minimum ventilation rate There is a general agreement between ASHRAE and EN standards that both contributions from people and contributions from buildings (materials, furnishing, HVAC systems) must be taken into account when specifying the required ventilation rate. The standards for specifying ventilation rates should distinguish between buildings with low-emitting materials and buildings with high-emitting materials. This should increase the interest in establishing better test methods and better labelling of building materials.

68 CONCLUSIONS Whether the required ventilation rate should be based on adapted or un-adapted persons should be evaluated on a case-by-case basis between rooms and the activities they serve; but at the same time, the health must be taken into account. For better evaluation of the health risk there is a need for threshold limit values that safeguard health in non-industrial environments In the future the goal must be a full analytical calculation of the minimum required ventilation rate (taking into account material emissions, air cleaning, etc)