The Town Hall of Zevenhuizen The town hall

The Town Hall of Zevenhuizen The town hall of Zevenhuizen Presentation of the building Monitoring The winter monitoring The summer monitoring Major findings More information. . . Back to “Select a building” Nat. Vent n n S. H. Liem, A. H. C. van Paassen M. Verwaal, H. F. Broekhuizen Delft, April 1998

Building presentation (1. . . ) Technical specifications The town hall of Zevenhuizen n Built in 1987 by architect Becka of The Hague and owned by the municipal of Zevenhuizen. n It is a two storey building. The total floor area is 1400 m 2 and a volume of 4200 m 3. At the moment 50 people work in the building. Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings n More information. . . Back to “Select a building” Nat. Vent The floor and the flat roof are of 250 mm concrete. The corridors and hall have exposed ceilings. The office rooms have closed lowered ceilings. The internal load in the office rooms of lighting is ~20 W/m 2. Office at the north side of the building

Building presentation (2. . . ) Ventilation system The town hall of Zevenhuizen Extraction openings Presentation of the building Monitoring set -up The ventilation system is based on: Monitoring results n The summer monitoring openable windows, doors and cracks. The winter monitoring Major findings n More information. . . Back to “Select a building” Nat. Vent natural supply through Office S Corridor Office N mechanical exhaust. During office hours in the winter, the exhaust air is extracted from the room through canals in the ceiling (3000 m 3/h).

Building presentation (3|) Building concept The town hall of Zevenhuizen n Presentation of the building ventilation system. During office hours in the winter the system extracts 3000 m 3/h (~ 0. 75 ACH) indoor air. Monitoring set -up Monitoring results n Major findings Internal blinds More information. . . Back to “Select a building” The risk of overheating is reduced by: The use of intensive (night) ventilation to cool down the building mass: In the summer, when the indoor temperature is higher than 21°C and the difference between the indoor and the outdoor temperatures exceeds 3 K, the ventilators run at full speed (6500 m 3/h ~ 1. 5 ACH). To prevent to high pressure differences a louvre window opens automatically when the extract ventilators are running at full speed. n Solar radiation is partly reduced by internal sun shades. n The summer monitoring The winter monitoring The Indoor Air Quality is controlled by the Louvre window Nat. Vent

Monitoring (1. . . ) The monitoring scheme The town hall of Zevenhuizen Presentation of the building n The rooms 1. 23 s, 1. 23 w, 1. 24 and 1. 25 on the first floor of the west wing were scheduled to be monitored. (see plan on next slide . . . ). n Actually room 1. 24 and room 1. 25 are one room with a volume of 127 m 3 and facing North. Room 1. 23 is a Lshaped room of approximately 90 m 3 and facing South. For the monitoring this room was divided in 1. 23 s and 1. 23 w. n Three temperatures were monitored in each room: global air temperature at 0. 1 m and 1. 1 m and the wall temperature. The ventilation rate, the indoor and outdoor CO 2 concentration levels and humidities were measured using a Bruel & Kjær 1302 unit. Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Nat. Vent

Monitoring (2|) Monitoring plan The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Nat. Vent N

Monitoring results The town hall of Zevenhuizen n The following slides show the summer and winter monitoring results. n South facing rooms have excessive solar gains. Although the internal sun shading is used, there is some overheating on sunny days. Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Nat. Vent n The CO 2 concentration is approximately 750 to 1000 ppm in the summer. In the winter this stays at the same level. At night and at weekends falls rapidly to the outdoor level of 400 ppm. n The ventilation rate is high in the winter and is higher in rooms on the South side of the building than in those on the North. At night and during the weekends it is very low. (See charts on next slides …)

Summer monitoring (1. . . ) hot period The town hall of Zevenhuizen Presentation of the building Text. Tint. -south Monitoring set -up Monitoring results Tint. -north The summer monitoring The winter monitoring Major findings Solar radiation More information. . . Back to “Select a building” Nat. Vent During a very hot period, the internal temperatures rise to 28°C (=slight overheating). The temperatures in the offices at the South side are higher than at the North side. This difference is caused by the solar gains. A more effective shading device (external instead of external shades) could further improve the comfort.

Summer monitoring (2. . . ) hot period - temperature distribution The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” The histogram of the temperatures in the different offices shows clearly that thermal comfort in the North-offices is considerable better than in the South offices. External shading devices (instead of internal) could reduce the difference. Nat. Vent

Summer monitoring (3. . . ) typical period The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” In a normal summer period during office hours the internal temperature in a room on the North façade is very comfortable with only natural ventilation through open windows. The ventilation system is shut off. This results in an air change rate of 4 -5 ACH. Sometimes the windows stay open during the night to cool down the building. Nat. Vent

Summer monitoring (4. . . ) typical period The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Although the indoor temperature in a room on the South facade in a normal summer period during office hours is higher than in the North room, it is just within the comfort limits. By using outdoor sun shading the solar gain can be reduced. The air change rate is with 5 -7 ACH higher than in the North façade. At night the windows stay open to cool down the building. Nat. Vent

Summer monitoring (5. . . ) typical period The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” The CO 2 concentration level during office hours in a North room is very acceptable with an average of 800 ppm. Sometimes it rises to nearly 1000 ppm, but it is still well below the allowable limit of 2000 ppm. . At night and in the weekends this drops to the outdoor level of 450 ppm. The IAQ can be considered good Nat. Vent

Summer monitoring (36. . ) typical period The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” During office hours the CO 2 concentration level is below 1000 ppm, this is much lower than the limit of 1200 ppm. At night and at weekends this drops to the outdoor level of 450 ppm. The IAQ can be considered good. Nat. Vent

Summer monitoring (7|) typical period - ventilation rates The town hall of Zevenhuizen Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Nat. Vent Because of the solar gains, the internal temperatures at the South side of the building are higher than at the North side. Hence , the ventilation rate is also higher: windows are opened sooner to cool the rooms than those on the North side.

Winter monitoring (1. . . ) temperatures The town hall of Zevenhuizen Presentation of the building Tint. -north Monitoring set -up Monitoring results weekend The summer monitoring The winter monitoring Text. Major findings More information. . . Back to “Select a building” The indoor temperatures are comfortable (20 to 23°C). During the weekend, the heating power is reduced Nat. Vent

Winter monitoring (2|) indoor air quality The town hall of Zevenhuizen Presentation of the building Monitoring set -up Tint. -north Monitoring results The summer monitoring weekend The winter monitoring Text. Major findings Ventilation rate More information. . . Back to “Select a building” CO 2 -conc. The ventilation rate during office hours is between 3 -4 ACH. This air supply leads to a good IAQ: the CO 2 concentration during office hours is never higher than 800 ppm. Sometimes the ventilation rates outside office hours are quite high (up to 3. 5 ACH ). Reducing this unnecessary air change also reduce ventilation losses. Nat. Vent

Major findings The town hall of Zevenhuizen n Thermal summer comfort: l The measurements show that indoor conditions are generally comfortable in the summer. However during hot periods there are some overheating problems in the South oriented offices. l One could achieve lower indoor temperatures in the offices at the South side of the building, by installing external shading devices on the South side instead of internal shading devices. l It is also important to note that at the moment the internal blinds are controlled manually. Automatic control might achieve further reductions of solar gains at any time. n The Indoor Air Quality: l In the summer the ventilation rate during office hours is 6 -10 ach in the summer and 4 -5 ach in the winter. l The CO 2 concentration level is 750 ppm during office hours and 400 ppm in at other times. Hence the IAQ is good. Presentation of the building Monitoring set -up Monitoring results The summer monitoring The winter monitoring Major findings More information. . . Back to “Select a building” Nat. Vent

More information. . . The town hall of Zevenhuizen Presentation of the building Monitoring results The winter monitoring The summer monitoring Find more information on the PROBE building in the following documents: Reports Monitoring Reports Summary Reportsnl 2 summ. pdf l global presentation of the buildings ( 4 p. /building) l contents: building description - ventilation strategy and technology winter and summer monitoring results - conclusions Reports Monitoring Reports Detailed Reportsnl 2 det. pdf l detailed reports of all 19 monitoring campaigns ( 20 p. /campaign) l contents: monitoring set-up - analysis of results - conclusions Major findings More information. . . Back to “Select a building” Nat. Vent You can read and print pdf-files with the Acrobat® Reader ® 3. 0. Program. This program is free. Download it from the Acrobat web site: www. adobe. com OR run the installation file ar 32 e 301(1). exe in the directory Installation