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Building AdVent Advanced ventilation technology to demonstrate good air quality and thermal comfort. www.buildingadvent.com. Jarek Kurnitski D.Sc., Adjunct Professor Sitra , the Finnish Innovation Fund Helsinki University of Technology, HVAC-Technology. REHVA Supporters Seminar
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Building AdVentAdvanced ventilation technology to demonstrate good air quality and thermal comfort www.buildingadvent.com Jarek Kurnitski D.Sc., Adjunct Professor Sitra, the Finnish Innovation Fund Helsinki University of Technology, HVAC-Technology REHVA Supporters Seminar 10.12.2009 Brussels 2.1.2020 1 TKK
Partners • Buro Happold Consulting Engineers UK • Brunel University UK • National and Kapodistrian University of Athens Greece • Helsinki University of Technology Finland • Aalborg University Denmark • Faculdade de Engenharia da Universidade do Porto Portugal • Dissemination focussed partners • INIVE • UIA • REHVA
Introduction • The Building AdVent project: • made an attempt to find 18 excellent non-residential buildings with advanced ventilation technologies from all over Europe • the objective was to disseminate information to designers on successfully implemented ventilation systems
How to measure “an advanced ventilation technology”? • Three level assessment based on measurements and occupant questionnaires: • Measured indoor environmental performance: • room temperature, (air velocity) and ventilation rate or CO2 concentration during summer and winter seasons • Questionnaire survey to assess occupant satisfaction and to identify major indoor climate complaints • Energy performance data (from utility bills or measured): • heating, cooling and other electrical energy use • Building AdVent project did this assessment for 18 non-residential buildings with advanced ventilation technologies from all over Europe
Examples of the buildings Greek Office • 23 m2/pers • AC • Fan-coils combined with ceiling fans • Centralized mechanical vent. • English Office • 10 m2/pers • Natural vent. by automatically controlled high-level windows • Night ventilative cooling only • Finnish Office • 25 m2/pers • AC • Chilled beams • Centralized mechanical vent. CAV 3 l/(s m2)
Long and short term measurements with the aim to end up with indoor climate foot-print • Indoor climate foot-print according to EN 15251:2007: • Foot-print of thermal comfort based on measured temperatures • Foot-print of IAQ based on ventilation rate an example from EN 15251
Long and short term measurements for the foot-print • Indoor air quality • Estimation based on CO2 concentration • In CAV systems estimation based on ventilation rate • General thermal comfort • Temperatures from selected rooms (measurements or from BMS) • Local thermal discomfort (not used in the foot-print) • Draft rate – air velocity measurements – measurement period of 3 minutes, i.e. has to be representative • Measurements during representative summer and winter days • Challenging in naturally ventilated buildings • Results depend on measurement point and time
Examples of energy performance data • Annual energy use in the buildings. Heating and cooling energy is not adjusted for climatic differences between the building locations.
Occupant questionnaire/ indoor climate complaints • Survey response: satisfaction with environment based on occupants responses • If there is something wrong, this can be easily seen from questionnaire • Measured performance of Category I (EN 15251) may be ranked as satisfaction below 80% (expected to be >80%)
Selection of rooms/measurement points for the foot-print – an example of 6 storey buildingGround floor 102 v, T 124 v 149 v 146 v, T measurement points and parameters (red circles)
First floor 204 v, T 204 v, T 224 v, T 244 v, T
Third floor 401 v, T 422 v, T 439 v, T 461 v, T • 12 measured rooms/open plan offices in total in this case • Measurements from ground, 1st and 3rd floors (6-storey building), selected together with building manager so that most critical locations were measured • Ventilation rates from commissioning measurement protocols (CAV system)
Air velocity measurements – draft rate (ISO 7726)– local thermal discomfort
Daily temperature fluctuations Daily temperature fluctuations during one week: a room with highest, typical and smallest fluctuation (measured with small loggers in this case)
An example of foot-print of thermal comfort and IAQ • Foot-print of general thermal comfort based on measured temperatures (weighted with area) and and a foot-print of IAQ based on ventilation rate • Room temperatures remained between 23.5 °C and 25.5 °C (category I, EN15251, CR 1752) for 97 % of occupied hours for cooling season. • In heating season temperature was between 21.0 °C and 23.5 °C (category I) in occupied hours for the full measurement period. Daily temperature fluctuations were typically around 1.0 °C to 1.5 °C in the occupied hours during heating season.
Conclusions from the AdVent approach • Performance assessment needs both measured and questionnaire data • Results from Building AdVent buildings show how difficult it is to achieve good occupant satisfaction with indoor climate • Questionnaire is sensitive to many confounders, but: • If something is wrong, this can be easily seen from results – powerful tool for screening • Measured performance of Category I (EN 15251) still can lead to occupant satisfaction below 80% in such simple field surveys (expected to be >80%) indicating a need of further analyses • Expectancy factor may cause deviation in comparison between buildings (Building AdVent experience) • More or less measurements needed in any case: • IAQ assessment based on ventilation rates or CO2 measurement – straightforward in any building • General thermal comfort/room temperatures also easily measurable/accessible • Representative results of draft rate/air velocity most challenging especially in naturally ventilated buildings
The best buildings? Many confounders in the measurements and energy data Top 5 based on occupant satisfaction: • Case Study No 11 CHH – ChristophorusHaus, MIVA, Stadl-Paura, Austria (>77%, balanced) • Case Study No 9, YIT Office Building, Turku, Finland (>73%, balanced) • Case Study No 4 Edifício Solar XXI, Lisbon, Portugal (>73%, hybrid) • Case Study No 12 SFO Spirehuset, Hirtshals, Denmark (>67%, natural pulse) • Case Study No 15 Rijkswaters taat Building, Terneuzen, Netherlands (>67%, natural)