Building AdVent Advanced ventilation technology to demonstrate good air quality and thermal comfort TKK REHVA Supporters Seminar Brussels Jarek Kurnitski D.Sc., Adjunct Professor Sitra, the Finnish Innovation Fund Helsinki University of Technology, HVAC-Technology

Partners Buro Happold Consulting EngineersUK Brunel University UK National and Kapodistrian University of Athens Greece Helsinki University of TechnologyFinland Aalborg UniversityDenmark Faculdade de Engenharia da Universidade do PortoPortugal 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 CO 2 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 m 2 /pers AC Fan-coils combined with ceiling fans Centralized mechanical vent. Finnish Office 25 m 2 /pers AC Chilled beams Centralized mechanical vent. CAV 3 l/(s m 2 ) English Office 10 m 2 /pers Natural vent. by automatically controlled high- level windows Night ventilative cooling only

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 CO 2 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%)

102 v, T 124 v 146 v, T 149 v Selection of rooms/measurement points for the foot-print – an example of 6 storey building Ground floor measurement points and parameters (red circles)

204 v, T 204 v, T 224 v, T 244 v, T First floor

401 v, T 422 v, T 439 v, T 461 v, T Third floor 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

Air velocity, draft rate and PPD – a summer day

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 CO 2 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: 1.Case Study No 11 CHH – ChristophorusHaus, MIVA, Stadl-Paura, Austria (>77%, balanced) 2.Case Study No 9, YIT Office Building, Turku, Finland (>73%, balanced) 3.Case Study No 4 Edifício Solar XXI, Lisbon, Portugal (>73%, hybrid) 4.Case Study No 12 SFO Spirehuset, Hirtshals, Denmark (>67%, natural pulse) 5.Case Study No 15 Rijkswaters taat Building, Terneuzen, Netherlands (>67%, natural)