Ventilation standards and demand controlled ventilation

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1 Ventilation standards and demand controlled ventilation Jarek Kurnitski D.Sc., Adjunct Professor Sitra, the Finnish Innovation Fund Helsinki University of Technology, HVAC-Technology J. Kurnitski Air Academy Tallinn 2009

2 Contents Performance criteria for ventilation ventilation rates Air distribution Finnish Indoor Environment Classification 2008 Sisäilmastoluokitus 2008 Demand controlled ventilation examples J. Kurnitski 2009

3 Indoor environmental performance of buildings Indoor climate (TC, IAQ, lighting, acoustics) Energy performance and environmental performance In the design and in the assessment of performance of a existing building, ventilation rate is the most straightforward, however indirect measure of IAQ, together with low-polluting and dry building materials Indoor air quality 100 % Thermal environment, cooling season 11 % 9 % 22 % 58 % Thermal environment, heating season 3 % 27 % 69 % IV III II I An example of the foot-print of indoor climate of a building according to EN (based on ventilation rate per person and very-low polluting materials) J. Kurnitski 2009

4 Performance criteria for ventilation Ventilation (outdoor air flow) has to be adequate to remove and dilute the indoor generated pollutants and humidity, and provide acceptable level of contaminants in the indoor air Source control the first alternative to improve indoor air quality Ventilation shall be energy efficient and arranged so that it does not deteriorate indoor air quality and climate, and does not cause any harm to the occupants or to the building Ventilation rates should be based on the pollution loads and use of the building Many standards and a lot of scientific evidence related to ventilation J. Kurnitski 2009

5 Evidence on SBS, PAQ, sick-leave, productivity (non-residential) Performance % sick leave % lower Outdoor air supply rate (L/s per person) Outdoor air supply rate (L/s per person) Ventilation and performance of office work in relation to 6.5 L/s per person (Seppänen 2006) Ventilation and short-time sick leaves in open-plan offices (Milton 2000) J. Kurnitski 2009

6 Ventilation often linked with temperature control Relative performance as a function of temperature REHVA Guidebook 6 (2006) J. Kurnitski 2009

7 Low ventilation increases humidity and symptoms in residences ( ) (P=0.024) >100mites per 0.1g mattress dust h -1 Median air change in homes 0 = >0.50 Air change rate (h -1 ) Risk (odds ratio) of symptoms of asthma and allergy (wheezing, rhinitis, eczema) as a function of ventilation rates in single family houses (Bornehag et al. 2005) Prevalence of house dust mites in homes (Harving et al. 1993) J. Kurnitski 2009

8 Main ventilation standards General standards (indoor climate), system standards and component standards CEN CR 1752:1998 Ventilation for buildings. Design criteria for the indoor environment EN 15251:2007 Criteria for the Indoor environment including thermal, indoor air quality, light and noise ASHRAE 62.1 (2007) Ventilation for acceptable indoor air quality ASHRAE 62.2 (2007) Ventilation and acceptable indoor air quality in low-rise residential buildings EN 13779:2007 Ventilation for non-residential buildings Performance requirements for ventilation and room-conditioning systems (ISO 7730 & ASHRAE 55 thermal comfort standards)

9 System standards EN 13779:2007 Ventilation for non-residential buildings Performance requirements for ventilation and room-conditioning systems EN Ventilation for buildings - Design and dimensioning of residential ventilation systems EN Ventilation for buildings - Symbols, terminology and graphical symbols EN 15241:2007 Ventilation for buildings - Calculation methods for energy losses due to ventilation and infiltration in commercial buildings EN 15242:2007 Ventilation for buildings - Calculation methods for the determination of air flow rates in buildings including infiltration EN 15243:2007 Ventilation for buildings Calculation of room temperatures and of load and energy for buildings with room conditioning systems

10 Component standards (some examples) EN Ventilation for buildings Air handling units Rating and performance for units, components and sections EN Ventilation for buildings Ductwork Strength and leakage of circular metal sheet ducts EN Ventilation for buildings Performance testing of components/products for residential ventilation Part 7: Performance testing of a mechanical supply and exhaust ventilation units (including heat recovery) for mechanical ventilation systems intended for single family dwellings EN Ventilation for buildings - Performance testing of components/products for residential ventilation - Part 8: Performance testing of unducted mechanical supply and exhaust ventilation units [including heat recovery] for mechanical ventilation systems intended for a single room + many EUROVENT standards

11 Pollutant mass balance q V C o εc in G Cin q V q v = C in G C o 1 ε () 1 q v the volume flow rate of supply air in m 3 /s G the net mass flow rate of emission to the room air in mg/s C in the allowed concentration in the room in mg/m 3 C o the concentration in the supply air in mg/m 3 ε the ventilation efficiency, (ε = 1 for complete mixing to ε = 2 for ideal piston flow) J. Kurnitski 2009

12 Humidity balance The same type mass balance equation applies also for humidity balance of air. Removal of indoor generated humidity: q v G ν in ν o = h ( 2) q v the volume flow rate of supply air in m 3/ s G h the indoor humidity generation in the room in g/s ν in the humidity by volume of the indoor air in the room in g/m 3 ν o the humidity by volume of the supply (outdoor) air in g/m J. Kurnitski 2009

13 Ban smoking indoors to reduce need for ventilation ETS NICOTINE 1 μg / m³ 277 Ventilation rate per person depends on the criteria Oxygen is never the critical criteria Acceptable long term level of ETS cannot be achieved with ventilation Ventilation, L/s per person J. Kurnitski ΔO 2-2 % CO ppm BODY ODOUR 80 % ETS ODOUR 1 cig / 2 h

14 Time dependent concentration Different pollutants check all relevant ones (applies mainly for industrial ventilation) As a rule, source control is preferable to ventilation Eq.(1) is for a steady-state and assumes that all pollution generated in room is carried out with the airflow no other sinks in the room When the emission-period is short, the stationary equilibrium-concentration may not be achieved or the airflow can be reduced for a given maximum concentration level. The time-dependency: C in ( t) C o = C in (0) + G q v 1 e qv t V () 3 C in in (t) the concentration in the room at time t in mg/m 3 C o the concentration in the supply air in mg/m 3 C in in (0) the concentration in the room at the beginning (t = 0) in mg/m 3 q v the volume flow rate of supply air in m 3 /s G the mass flow rate of emission in the room in mg/s V the volume of air in the room in m 3 t the time in s J. Kurnitski 2009

15 From IAQ to ventilation rate (buildings designed for human occupancy) There do not exist a common standard index for the IAQ which will allow to use Eqs. (1) (3) for determination of required ventilation rate Acceptable concentration of many various pollutants in indoor air is not known, especially for the mixtures of hundreds of the compounds found in the indoor air IAQ may be expressed as the required level of ventilation or carbon dioxide (CO 2 ) concentration CO 2 can be used as a surrogate of ventilation rates, but its use to measure ventilation is uncertain as its concentration in buildings seldom reaches steady state due to variations in occupancy, ventilation rates and outdoor air concentration Steady state values of carbon dioxide concentration can be calculated from CO 2 generation of l/s per occupant in office buildings J. Kurnitski 2009

16 From IAQ to ventilation rate IAQ is influenced by emission from people and their activities (bio effluent, smoking), and from building, furnishing as well as from ventilation and air conditioning system itself (i.e. building components) The required ventilation is based on health and comfort criteria. In most cases the health criteria will also be met by the required ventilation for comfort. Health effects may be attributed to specific components of emission and if you reduce concentration of one source you also reduce concentration of others. Comfort is more related to the perceived air quality (odor, irritation). In this case different sources of emission may have an odor component that adds to the odor level. There is however no general agreement how different sources of emission should be added together J. Kurnitski 2009

17 EN & ASHRAE 62 In the latest standards (EN 15251, ASHRAE 62.1 and 62.2) the criteria is expressed as addition of people (smoking, non-smoking) and building components. The total ventilation rate for a room: q tot = n q p + A q B q tot total ventilation rate of the room, l/s n design value for the number of the persons in the room,- q p ventilation rate for occupancy per person, l/s, pers A room floor area, m 2 q B ventilation rate for emissions from building, l/s,m J. Kurnitski 2009

18 Ventilation rates for occupants (q p ) only (EN 15251) Category I (high): 10 l/s, pers Category II (medium): 7 l/s, pers Category III (basic): 4 l/s, pers. Body odor (bio effluent) criteria for persons entering the room (in ASHRAE for persons staying in the room) EN J. Kurnitski 2009

19 Ventilation rates (q B ) for the building emissions (EN 15251) Category Very low polluting building, l/s, m 2 Low polluting building, l/s, m 2 Non lowpolluting building, l/s, m 2 I (high) 0,5 1,0 2,0 II (medium) 0,35 0,7 1,4 III (basic) 0,3 0,4 0,8 An example of ventilation rates for offices depending on the pollution load in three categories (EN 15251) Category Occupants only, l/s, m 2 Low-polluting Building, l/s, m 2 Non low-polluting Building, l/s, m 2 I (high) II (medium) III (basic) J. Kurnitski 2009

20 Ventilation rates for residences (EN 15251) J. Kurnitski 2009

21 Ventilation rates for residences (EN 15251) J. Kurnitski 2009

22 Summary on ventilation rates Minimum ventilation rate l/s per person, app. 1 l/s per m 2 in office buildings with normal occupant density For better IAQ and productivity up to 2 l/s per m 2 can be recommended for typical landscape and cellular offices This is supported by latest reviews by Seppänen and Fisk (2004) and Fisk and Seppänen (2007) that summarise the effect of ventilation in respect of health and productivity as follows: ventilation rates below 10 l/s per person are associated with a significantly higher prevalence of health or perceived air quality outcomes increases in ventilation rates above 10 l/s per person, up to approximately 20 l/s per person, are associated with a significant decrease in the prevalence of SBS (sick building syndrome) symptoms or with improvements in perceived air quality and task performance and productivity. relative to natural ventilation, air conditioning is often associated with a statistically significant increase in the prevalence of one or more SBS symptoms For the residential buildings it is summarized that the ventilation rates below 0.5 ach (air change per hour) are a health risk in Nordic residential buildings (Wargocki et al and Levin and Sundell 2007) concerning dwellings in a cold climate J. Kurnitski 2009

23 Typical ventilation rates in the design l/s per person difficult to use in the design (occupant density is often not known) l/s per m 2 values are common design specification Typical airflow rates: 2 l/s per m 2, 2.5 1/h in offices/commercial buildings 3 4 l/s per m 2, 3 4 1/h in classrooms l/s per m 2, /h in homes If No of person known, 10 l/s per person (concert halls etc.) Still a lot of variation in national codes especially for homes J. Kurnitski 2009

24 Air distribution The airflow pattern in a ventilated room depends on the selection and location of supply air devices whereas extract air devices have only small effect on it This is due to high momentum (air jet) of supply air compared to almost zero velocity near the suction point of extract air Air distribution to the occupied zone: serve supply air avoid stagnant air avoid draft J. Kurnitski 2009

25 Mixing and displacement ventilation There are two main types of airflow pattern: mixing (dilution) ventilation and displacement ventilation. Mixing flow pattern Displacement flow pattern Mixing ventilation is used in rooms with normal height (most homes and offices) and it can be provided with supply air diffusers, fan-coils or chilled beams etc. Complete mixing the pollutants concentration diluted with ventilation is equal in the whole room. Especially in high rooms such as concert halls, auditoriums etc it is more efficient to bring fresh supply air directly to breathing zone. In displacement ventilation a stratified flow is created using a few degrees lower supply air temperature than room temperature J. Kurnitski 2009

26 Examples of mixing ventilation J. Kurnitski 2009

27 Use high efficiency air distribution in rooms (applies mainly in high rooms) 6-8 L/s = 10 L/s Displacement air distribution Mixing air distribution Skistad et al. 2002, REHVA Guidebook J. Kurnitski no on Displacement Ventilation

28 Piston flow The opposite of the mixing flow pattern is the ideal piston flow in which the air flow is laminar and the room air is not mixed at all with the supply air This flow pattern with maximum possible ventilation effectiveness is used in special cases such as operating theatres and other super clean rooms Laminar piston flow pattern J. Kurnitski 2009

29 Demand controlled ventilation Ctrl SENSOR CO 2 ODOUR VOC PARTICLES Ventilation rate, q v Max Min Min (~600 ppm) CO2- concentration Max (~1000 ppm) CAV, VAV, AQCV Air flows in the rooms can controlled according to the contaminant loads or concentrations, term G in equation (1) A room sensor can be one of the following: carbon dioxide, mixed-gas, attendance, combined CO 2 /mixed-gas, combined CO 2 /temperature or combined CO 2 /CO. At present mainly CO 2, temperature and attendance sensors are used for AQCV in normal spaces due to cost and unreliability of other types of sensors. CO-sensors are used in special cases such as large garages J. Kurnitski 2009

30 The Finnish IAQ Classification System Sisäilmastoluokitus 2008 Target values for indoor air quality and climate (S) Instructions for design and construction (P) Requirements for building products (M) Building and constructions HVAC systems Classification of Building materials Classification of ventilation components

31 Aiming at high IAQ and TC The clients of building industry want better indoor environment that just a minimum requirements Significance of indoor climate for health, comfort and productivity has been well recognized The voluntary IAQ classification and labeling system is a tool for setting targets above minimum

32 Target values (S) Three categories S1 individual S2 comfortable S3 satisfactory Specified from client s and engineer s viewpoints For ventilation rates, similar approach to EN 15251

33 How it works? Design criteria Construction criteria Commissioning IAQ and TC standard S1 or S2 HVAC-design values Design specifications for moisture safety M1 materials M1 ventilation products Building site moisture control specifications P1 ventilation cleanliness P1 construction cleanliness Commissioning spec. Operation End result complies with S1 or S2 targets after 6 months use

34 Tekniset tavoitearvot Kriteerit tavoitearvoille terveyden ja viihtyisyyden kannalta merkittäviä rakennusprosessin osapuolten hallittavissa todennettavissa luotettavasti kohtuukustannuksin Sisäilmastoluokitus 2008:ssa: operatiivinen lämpötila ilman liikenopeus hiilidioksidipitoisuus radonpitoisuus valaistussuureet (viittaus standardiin) akustisen suunnittelun suureet (viittaus standardiin)

35 Osa tavoitearvoista on korvattu teknisillä vaatimuksilla TVOC, ammoniakki, formaldehydi, hajut käytettävä vähäpäästöisiä materiaaleja pienhiukaset käytettävä tuloilman suodatusta F8/F7 (vilkasliikenteisten katujen lähellä F9/F8) pöly ja lika rakennuksen ja ilmanvaihtokanavien pintojen puhtausvaatimukset mikrobit vaatimus veden- ja kosteudenhallinta-suunnitelmasta tupakansavu sisätiloissa tupakointi kielletty

36 Lämpötilan tavoitearvot Operatiivinen lämpötila oleskeluvyöhykkeellä [ C ] S Enimmäi sarvo t op Vähimmäisarvo Ulkolämpötila (24 h keskiarvo) [ C]

37 Operatiivinen lämpötila oleskeluvyöhykkeellä [ C ] 30 S Enimmäi sarvo 23 t op Lämpötilan tavoitearvot Vähimmäisarvo Lämpötilan tulee pysyä 90 % käyttöajasta alueella t op ± 1,0 C Ulkolämpötila (24 h keskiarvo) [ C]

38 Operatiivinen lämpötila oleskeluvyöhykkeellä [ C ] S1 Operatiivisen lämpötilan on oltava tila-/huoneistokohtaisesti aseteltavissa välillä t op ± 1,5 C. Enimmäi sarvo t op Lämpötilan tavoitearvot Vähimmäisarvo Lämpötilan tulee pysyä 95 % käyttöajasta alueella t op ± 0,5 C Ulkolämpötila (24 h keskiarvo) [ C]

39 Lämmitys- ja jäähdytysjärjestelmien suunnitteluarvoja S1 S2 S3 Jäähdytysjärjestelmän suunnitteluarvo C Lämmitysjärjestelmän suunnitteluarvo C 21,5 21,5 21,5 Lämpötilan tilakohtainen säädettävyys, talvi C Lämpötilan tilakohtainen säädettävyys, kesä C Ilman nopeus, t ilma =21 C m/s <0,14 <0,17 <0,20 Ilman nopeus, t ilma =23 C m/s <0,16 <0,20 <0,25 Ilman nopeus, t ilma =25 C m/s <0,20 <0,25 <0,35 Pystysuuntainen lämpötilaero (0,1/1,1 m) C <2 <3 <4 Lattian pintalämpötila, vähintään C Lattian pintalämpötila, enintään (lattialämm.) C Ilman suhteellinen kosteus, talvi % >

40 Ilman laadun tavoitearvot S1 S2 S3 CO 2 -pitoisuus Radonpitoisuus Olosuhteiden pysyvyys, tsto 95 % 90 % -- Olosuhteiden pysyvyys, asunnot 90 % 80 % -- Võrdluseks: Energiatõhususe miinimumnõuded (määrus 10):

41 SI2008: Tavoitearvoja täydentävät vaatimukset S1- ja S2-luokissa M1-luokan materiaalien käyttö P1-luokan rakennustyöt P1-luokan ilmanvaihtojärjestelmä F8-luokan tuloilmansuodatus Suunnitelmallinen kosteudenhallinta

42 Cleanliness criteria for ventilation components Oil concentration g/m 2 of ducts <0.05 terminal units and dampers <0.05 pressed components <0.3 Mineral fibres (MMVF), f/cm 3 <0.01 Dust concentration, g/m 2 <0.5 Odour acceptability of air quality passing through the components >0.05

43 Cleanliness criteria for ductworks Brush cleaned P1 P1 P1 P2 P2 Not accepted

44 Construction and installation works are critical regarding the cleanliness of the ventilation system

45

46 M1 labeled products Today there are over 1200 classified products by over 110 producers. The largest product groups: Plaster, rendering, putties, fillers, flooring, paints and varnishes, building boards and mineral wool. See for complete listing

47 Experience from practice since 1995 Over 1200 materials with M1-label -->reduces emissions by a factor of 10 S1 targets have been met in building projects-->realistic Category S2 well accepted as target level-->above minimum Several new materials and products available -->helps product development

48 VOC emissions from M1-classified and non-classified products TVOC SER [µg/m 2 h] n=9 447 n=5 385 n=6 n=6 460 n=6 n=102 M n=36 PVC 82 n=35 Parquets 45 n=20 Adhesives n=58 Paints n=495 All materials M1 Non classified (VTT Building and Transport)

49 Use of M1-products and control of moisture gives good IAQ TVOC, μg/m S S S B108/107 B125/126 B303/304 3B/4B avo A619/B605 6B avo Helsinki Univ. of Tech / HVAC-lab. Measured results: Tuomainen et al. 2003, Saarela et al. 2004

50 Material emissions vs. ventilation rates Emissions dropped roughly by 10 times and general availability and use of M1 labelled materials makes it possible to use reduced airflow rates in buildings Significant equipment cost as well as energy savings potential (not yet used in practice) Reduction of air flow rates is addressed in new indoor climate standard EN :2007: q tot = n q p + A q B where q tot = total ventilation rate of the room, l/s n = design value for number of the persons in the room,- q p = ventilation rate for occupancy per person, l/s, pers A= room floor area, m 2 q B = ventilation rate for emissions from building, l/s,m 2

51 EN ventilation rates airflow reduction by a factor of 2 for very-low polluted buildings Type of building or space Cate - gory Floor area m 2 /person q p q B q tot q B q tot l/s,m 2 l/s,m 2 l/s,m 2 for occupan cy for very lowpolluted building for non-low polluted building Single office I 10 1,0 0,5 1,5 2,0 3,0 II 10 0,7 0,3 1,0 1,4 2,1 III 10 0,4 0,2 0,6 0,8 1,2 Landscaped office I 15 0,7 0,5 1,2 2,0 2,7 II 15 0,5 0,3 0,8 1,4 1,9 III 15 0,3 0,2 0,5 0,8 1,1 Confere nce room I 2 5,0 0,5 5,5 2,0 7,0 II 2 3,5 0,3 3,8 1,4 4,9 III 2 2,0 0,2 2,2 0,8 2,8

52 Ilmanvaihdon mitoitus Ulkoilmavirrat standardin EN-15251:2007 mukaisesti. Noudatettaessa Sisäilmastoluokituksen ohjeita voidaan rakennuksissa, joissa tupakointi on kielletty, käyttää ulkoilmavirtojen mitoituksessa erittäin vähäpäästöisen rakennuksen mitoitusarvoja S1-luokka: 0,5 l/s,lattia-m l/s, henkilö S2-luokka: 0,5 l/s,lattia-m l/s, henkilö Huonelämpötilan hallinta tai varautuminen muunto-joustoon saattaa edellyttää suurempia ilmavirtoja. Erityisistä epäpuhtauslähteistä johtuvien päästöjen aiheuttama ilmanvaihdon tarve on otettava tapauskohtaisesti huomioon. Ilmavirtoja on voitava säätää tilojen käytön muuttuessa. Normaalin käyttöajan ulkopuolella on rakennuksessa oltava perusilmanvaihto 0,1 0,2 l/s,m 2

53 Esimerkkejä tilakohtaisista ilmavirroista Tila Lattia-ala m 2 /hlö S1-luokka S2-luokka S3-luokka / D2 dm 3 /s per henkilö dm 3 /s per neliö dm 3 /s per henkilö dm 3 /s per neliö dm 3 /s per henkilö dm 3 /s per neliö Toimitila, normaali tilatehokkuus ,5 13 1,5 1,5 Toimitila, suuri tilatehokkuus ,0 11 1,5 1,5 Neuvotteluhuone ,0 9 4,0 8 4,0 Taukotila, kahvio 1,5 11 7,0 8 5,0 5,0 Hotellihuone ,5 12 1,0 10 1,0 Käytävä ja porrashuone 1 0,5 0,5 Hissikuilu Luokkahuone ,5 8 4,0 6 3,0 Luentosali ,5 8 7,5 6 6,0 Käytävä, aula koulussa ,5 8 4,0 4,0 Aula ,0 10 2,0 2,0 Päiväkoti ,0 9 2,5 6 2,5 Päiväkodin märkäeteinen (poisto) 5 5 5

54 Esimerkkejä tilakohtaisista ilmavirroista Tila Lattia-ala m 2 /hlö S1-luokka S2-luokka S3-luokka / D2 dm 3 /s per henkilö dm 3 /s per henkilö dm 3 /s per neliö dm 3 /s per henkilö dm 3 /s per neliö Liiketila ,5 10 2,0 2,0 Näyttelytila Kirjasto Salit (konsertti, teatteri, elokuva, koulun sali) Lämpiö dm 3 /s per neliö Kuntosali 6,0 6,0 6,0 Liikuntasali 5,5 4,0 4,0 Liikunta- ja uimahalli, urheilijat 2,5 2 2 Liikunta- ja uimahalli, katsojat Lääkäriasema Sairaala (ei koske erikoistiloja) Potilashuone 15 2,0 15 1,5 10 1,5 Leikkaussali Laboratorio

55 Basic question of IEQ: how to manage temperature and air distribution in classrooms with highly varying loads? South classroom: 30 students + solar radiation = cooling need North classroom, 15 students: heating need The same system should serve all classrooms No air conditioning, cost efficient ventilation system: Constant ventilation or demand controlled ventilation Supply air temperature compensation (cooling with outdoor air)

56 Temperature compensation + flow control Air-handling unit T S Radiator and thermostatic valve T E District heating supply District heating return District heating substation Ventilation rate, q v Max Min Min (~600 ppm) CO2- concentration Max (~1000 ppm) Supply air temperature and air flow rate control for cooling (with outdoor air + night ventilative cooling) T and CO 2 controlled ventilation (DCV)

57 Room temperature and CO 2 performance (Kurnitski et al. 2008) Sample of schools: 6 schools schools schools schools schools Room temperature, C Room temperature data during one week in May ( , mean outdoor temperature 13 C) from 63 classrooms. Data from the school time, from 8:00 to 14:00 on week-days ,2 0,4 0,6 0,8 1 Cumulative frequency, -

58 Temperature in August (warm period) , just after summer holidays Indoor temperature, C ,2 0,4 0,6 0,8 1 Cumulative frequency, - Indoor temperature, C Indoor temperature, C y = 0,39x + 18,92 R 2 = 0, y = 0,23x + 20,96 R 2 = 0,79 Outdoor temperature, C Outdoor temperature, C

59 Temperature simulations 2 or 6 classroom simulations with part load vs. full load occupancy Determining air flow rate and the control curve needed for the temperature control (no cooling!) CAV vs. DCV and heating season vs. summer performance students/south 20 students/north 30 students North 20 students North 20 students North No of persons students South 20 students South 20 students South :00 6:45 7:30 8:15 9:00 9:45 10:30 11:15 Time, hh:mm 12:00 12:45 13:30 14:15 15:00 15:45 16:30 17:15 18:00

60 Results, summer Room temperature, C South classroom in the summer CAV 180l/s DCV 180l/s, 40% / 100% CAV 300l/s DCV 300l/s, 40% / 100% DCV 300 l/s with night ventilative cooling <100 Ch above 25 C Room temperature, C North classroom in the summer CAV 180l/s DCV 180l/s, 40% / 100% CAV 300l/s DCV 300l/s, 40% / 100% Time, h Time, h Two ventilation rates, 6 L/s per person, 180 L/s per classroom in total or 10 L/s per person, 300 L/s per classroom in total. For both rates CAV system and DCV system with CO 2 and temperature control was simulated. DCV system had two air flow steps, 100 % and 40% of total airflow.

61 Results, heating season Room temperature, C South classroom in the heating season CAV 180l/s DCV 180l/s, 40% / 100% CAV 300l/s DCV 300l/s, 40% / 100% Time, h Room temperature, C North classroom in the heating season CAV 180l/s DCV 180l/s, 40% / 100% CAV 300l/s DCV 300l/s, 40% / 100% Time, h Excess degree-hours over 22 C should be less than 100 Ch (excess of 2 C during 5 hours is 2*5=10 Ch)

62 Which system works in all conditions? Sum of degree hours in weekdays at 08:00-15:00, Ch Heating season Summer period Ventilation system and classroom orientation Over 22 C Below 20 C Over 25 C Below 22 C Criterion, Ch CAV South classroom 300 L/s South classroom 300 L/s, with solar protection glasses North classroom 300 L/s, with low occupancy CAV + heating coil in supply duct for each classroom South classroom 300 L/s, with solar protection glasses North classroom 300 L/s, with low occupancy DCV % South classroom L/s, with solar protection glasses North classroom L/s, with low occupancy DCV % + night ventilative cooling South classroom L/s, with solar protection glasses North classroom L/s, with low occupancy

63 Temperature control Effective temperature control was possible by: 1. Supply air temperature going down to C with free cooling 2. Demand controlled ventilation (T and CO 2 control to avoid excessive cooling in North facade classrooms at part load) 3. Ventilation rate of 10 L/s per person (5 L/s per m 2 ) 19 Supply air temperature control curve Supply air to classrooms in the heating season Supply air to classrooms in the summer Supply air temperature C Exhaust air temperature C

64 Which air distribution solutions are capable for 15 C supply air temperature and 5 L/s per m 2 airflow rate without draft? Wall diffusers NO! Perforated duct?

65 Duct diffusers YES E F Ceiling diffusers YES Duct diffusers YES Displacement diffusers?

66 Toimistoesimerkki (KesEn tutkimushanke )

67 Toimistoesimerkki Huoneistoala 6245 htm 2, viisi kerrosta Ikkunoiden pinta-ala 35 % julkisivun alasta ja 19 % huoneistoalasta U ARVOT [W/m 2 K] Tapaukset Ulkoseinä Yläpohja Ikkunat LTO [%] Erillispoistojen LTO [%] Normi Normaali (YIT) Normi Passiivi ~0, Heikompi vaippa ~0, Normi 2010+Erillispoistojen LTO Normi 2010+Ulkopuolinen auringonsuojaus Normi 2010+Lasijulkisivu Normi 2010+Valaistuksen ohjaus Normi 2010+VAV

68 Energiankulutuksen laskenta: IDA-ICE- malli 3. krs 9 laskentavyöhykettä Säädata: Helsinki 2001 Lämmitys 21 C ja jäähdytys 25 C IV: 2,0 dm 3 /s/m 2 paitsi neuvotteluhuoneet 0,5-4,0 dm 3 /s/m 2 IV:n käyntiaika Ma-Pe klo 6-18 Valaistus 12 W/m 2 Laitteet 150 W/hlö (tietokone) 1 hlö/huone, avotoimistot 0.1 hlö/m 2 Läsnäoloprofiilit krs

69 Eri laskentavaihtoehtojen ostoenergiat Lämmitys Jäähdytys (COP=1) Sähkö TOT Normi 2010 Normi 2008 Normaali (YIT) Heikompi vaippa Erillisp. LTO Ulkop. auringons. Normi Normi Normaali Heikompi Erillisp. Ulkop. Lasijulkisivu Valaist. kwh/htm2/a (YIT) Passiivi vaippa LTO auringons. ohj. VAV Tilojen lämmitys Tuloilman lämmitys Tilojen jäähdytys Tuloilman jäähdytys LKV Puhaltimet Pumput Valaistus Laitteet Lasijulkisivu Valaist. ohj. kwh/htm2/a Passiivi VAV Lämmitys Jäähdytys (kauko) Sähkö TOT

70 Lisäinvestointien kannattavuus Sähkön hinnanmuutos sähkön hinta 0.10 /kwh ja kaukolämmön hinta 0,055 /kwh: Normi Normaali Heikompi Normi Erillisp. Ulkop. Lasi Valaist (YIT) Vaippa 2010 Passiivi LTO Auringons. julkisivu ohjaus VAV Lisäinvestoiniti Kustannuslisä % 1 % 0,7 % 0,5 % 0,0 % 1,3 % 0,2 % 0,3 % 7,1 % 0,3 % 1,7 % Ostoenergia kwh Ostoenergia /a Säästöä suhteessa normitaloon /a Maksuaika 3% korolla (vuotta) yli yli 40 ei ikinä 4 yli 40 Aika kunnes epäkannattava 3% korolla (vuotta) Alle 90 Alle 500 Alle 70 sähkön hinta 0.15 /kwh ja kaukolämmön hinta 0,055 /kwh: Normi Normaali Heikompi Normi Erillisp. Ulkop. Lasi Valaist (YIT) Vaippa 2010 Passiivi LTO Auringons. julkisivu ohjaus VAV Lisäinvestoiniti Kustannuslisä % 1 % 0,7 % 0,5 % 0,0 % 1,3 % 0,2 % 0,3 % 7,1 % 0,3 % 2 % Ostoenergia kwh Ostoenergia /a Säästöä suhteessa normitaloon /a Maksuaika 3% korolla yli yli 40 ei ikinä 3 40 Aika kunnes epäkannattava 3% korolla (vuotta) Alle 90 Alle 500 Alle 500 sähkön hinta 0.20 /kwh ja kaukolämmön hinta 0,055 /kwh: Normi Normaali Heikompi Normi Erillisp. Ulkop. Lasi Valaist (YIT) Vaippa 2010 Passiivi LTO Auringons. julkisivu ohjaus VAV Lisäinvestoiniti Kustannuslisä % 1 % 0,7 % 0,5 % 0,0 % 1,3 % 0,2 % 0,3 % 7,1 % 0,3 % 2 % Ostoenergia kwh Ostoenergia /a Säästöä suhteessa normitaloon /a Maksuaika 3% korolla yli yli 40 ei ikinä 2 31 Aika kunnes epäkannattava 3% korolla (vuotta) Alle 100 Alle 500 Alle 500

71 Lisäinvestointien kannattavuus - Sähkön ja kaukolämmön hinnanmuutos sähkön hinta 0.15 /kwh ja kaukolämmön hinta 0,085 /kwh: Normi Normaali Heikompi Normi Erillisp. Ulkop. Lasi Valaist (YIT) Vaippa 2010 Passiivi LTO Auringons. julkisivu ohjaus VAV Lisäinvestoiniti Kustannuslisä % 1 % 0,7 % 0,5 % 0,0 % 1,3 % 0,2 % 0,3 % 7,1 % 0,3 % 2 % Ostoenergia kwh Ostoenergia /a Säästöä suhteessa normitaloon /a Maksuaika 3% korolla yli 40 7 yli 40 ei ikinä 3 29 Aika kunnes epäkannattava 3% korolla (vuotta) 30 alle sähkön hinta 0.20 /kwh ja kaukolämmön hinta 0,11 /kwh: Normi Normaali Heikompi Normi Erillisp. Ulkop. Lasi Valaist (YIT) Vaippa 2010 Passiivi LTO Auringons. julkisivu ohjaus VAV Lisäinvestoiniti Kustannuslisä % 1 % 0,7 % 0,5 % 0,0 % 1,3 % 0,2 % 0,3 % 7,1 % 0,3 % 2 % Ostoenergia kwh Ostoenergia /a Säästöä suhteessa normitaloon /a Maksuaika 3% korolla yli 40 5 yli 40 ei ikinä 2 20 Aika kunnes epäkannattava 3% korolla (vuotta)

72 Toimistoesimerkin yhteenveto (KesEn tutkimushanke ) Vaipan lisälämmöneristäminen ei taloudellisesti kannattavaa. Ei sen takia, että rakentamiskustannukset olisivat niin suuria, mutta energiansäästö hyvin vähäinen. (Siis pientalotason lämmöneristys ei ole järkevä toimistorakennuksessa.) Tarpeenmukainen iv (VAV) ei vielä taloudellisesti kannattavaa Erillispoistojen LTO kannattava jo nyt Valaistuksen ohjaus kannattava jo nyt Tulokset eivät ole herkkiä energian hinnan muutokselle

73 Toimistoesimerkin yhteenveto (KesEn tutkimushanke ) Vaipan lisälämmöneristäminen ei taloudellisesti kannattavaa. Ei sen takia, että rakentamiskustannukset olisivat niin suuria, mutta energiansäästö hyvin vähäinen. (Siis pientalotason lämmöneristys ei ole järkevä toimistorakennuksessa.) Tarpeenmukainen iv (VAV) ei vielä taloudellisesti kannattavaa Erillispoistojen LTO kannattava jo nyt Valaistuksen ohjaus kannattava jo nyt Tulokset eivät ole herkkiä energian hinnan muutokselle