The Town Hall of Zevenhuizen S.H. Liem, A.H.C. van Paassen M.Verwaal, H.F. Broekhuizen Delft, April 1998 Presentation of the building Presentation of the

The Town Hall of ZevenhuizenThe Town Hall of Zevenhuizen

S.H. Liem, A.H.C. van Paassen M.Verwaal, H.F. Broekhuizen

Delft, April 1998

S.H. Liem, A.H.C. van Paassen M.Verwaal, H.F. Broekhuizen

Delft, April 1998Presentation Presentation

of the buildingof the building

MonitoringMonitoring

The winter The winter monitoringmonitoring

The summer The summer monitoringmonitoring

Major Major findingsfindings

The town hall of The town hall of ZevenhuizenZevenhuizen

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Presentation Presentation of the buildingof the building

Monitoring Monitoring set-upset-up





Monitoring Monitoring resultsresults



Building presentation Building presentation (1...) Technical specificationsTechnical specifications

Built in 1987 by architect Becka of The Hague and owned by the municipal of Zevenhuizen.

It is a two storey building. The total floor area is 1400 m2 and a volume of 4200 m3. At the moment 50 people work in the building.

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/m2.

Built in 1987 by architect Becka of The Hague and owned by the municipal of Zevenhuizen.

It is a two storey building. The total floor area is 1400 m2 and a volume of 4200 m3. At the moment 50 people work in the building.

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/m2.

Office at the north Office at the north side of the buildingside of the buildingOffice at the north Office at the north side of the buildingside of the building

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Building presentation Building presentation (2...) Ventilation systemVentilation system

Office S Office NCorridor

The ventilation system is based on:

natural supply through openable windows, doors and cracks.

mechanical exhaust. During office hours in the winter, the exhaust air is extracted from the room through canals in the ceiling (3000 m3/h).

The ventilation system is based on:

natural supply through openable windows, doors and cracks.

mechanical exhaust. During office hours in the winter, the exhaust air is extracted from the room through canals in the ceiling (3000 m3/h).

Extraction openingsExtraction openingsExtraction openingsExtraction openings

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Building presentation Building presentation (3|) Building conceptBuilding concept

The Indoor Air Quality is controlled by the ventilation system. During office hours in the winter the system extracts 3000 m3/h (~ 0.75 ACH) indoor air.

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 3K, the ventilators run at full speed (6500 m3/h ~ 1.5 ACH). To prevent to high pressure differences a louvre window opens automatically when the extract ventilators are running at full speed.

Solar radiation is partly reduced by internal sun shades.

The Indoor Air Quality is controlled by the ventilation system. During office hours in the winter the system extracts 3000 m3/h (~ 0.75 ACH) indoor air.

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 3K, the ventilators run at full speed (6500 m3/h ~ 1.5 ACH). To prevent to high pressure differences a louvre window opens automatically when the extract ventilators are running at full speed.

Solar radiation is partly reduced by internal sun shades.

Internal blindsInternal blindsInternal blindsInternal blinds

Louvre windowLouvre windowLouvre windowLouvre window

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Monitoring (1...) The monitoring scheme

The rooms 1.23s, 1.23w, 1.24 and 1.25 on the first floor of the west wing were scheduled to be monitored. (see plan on next slide ...).

Actually room 1.24 and room 1.25 are one room with a volume of 127 m3 and facing North. Room 1.23 is a L-shaped room of approximately 90 m3 and facing South. For the monitoring this room was divided in 1.23s and 1.23w.

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 CO2 concentration levels and humidities were measured using a Bruel & Kjær 1302 unit.

The rooms 1.23s, 1.23w, 1.24 and 1.25 on the first floor of the west wing were scheduled to be monitored. (see plan on next slide ...).

Actually room 1.24 and room 1.25 are one room with a volume of 127 m3 and facing North. Room 1.23 is a L-shaped room of approximately 90 m3 and facing South. For the monitoring this room was divided in 1.23s and 1.23w.

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 CO2 concentration levels and humidities were measured using a Bruel & Kjær 1302 unit.

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Monitoring Monitoring (2|) Monitoring planMonitoring plan

Control room

sa3

sa5

T7

T10

T11T12T13

T14T15T16

sa4

120 m³

su5

su4

90 m³

1.22

1.23

1.241.25

sa1

su1

127 m³ T4T5T6

sa2

su2

sa7(roof)

sa6

T17

su6

su3

l.v.T1T2T3

T0

*

*

Tn : thermocouple nsu : supply nozzlesa : sampling nozzlelv : air speed measurement

North

South

Control room

sa3

sa5

T7

T10

T11T12T13

T14T15T16

sa4

120 m³

su5

su4

90 m³

1.22

1.23

1.241.25

sa1

su1

127 m³ T4T5T6

sa2

su2

sa7(roof)

sa6

T17

su6

su3

l.v.T1T2T3

T0

*

*

Tn : thermocouple nsu : supply nozzlesa : sampling nozzlelv : air speed measurement

North

South

N

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Monitoring results

The following slides show the summer and winter monitoring results.

South facing rooms have excessive solar gains. Although the internal sun shading is used, there is some overheating on sunny days.

The following slides show the summer and winter monitoring results.

South facing rooms have excessive solar gains. Although the internal sun shading is used, there is some overheating on sunny days.

The CO2 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.

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 …)

The CO2 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.

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 …)

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Summer monitoring (1...) hot period

0

5

10

15

20

25

30

35

8/8 8/9 8/10 8/11 8/12 8/13 8/14 8/15 8/16

Date

Tem

pe

ratu

re [

0C

]

0

250

500

750

1000

1250

1500

1750

So

lar

rad

iati

on

[W

/m2]

Tint.-south

Tint.-north

Solar radiation

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.

Text.

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Summer monitoring (2...) hot period - temperature distribution

Indoor Temperature during office hours in August

0

10

20

30

40

50

60

70

80

18 19 20 21 22 23 24 25 26 27 28 29 30

Temperature [0C]

[Ho

urs

]

R1.25

R1.24

R1.23s

R1.23w

The histogram of the temperatures in the different offices shows clearly that the thermal comfort in the North-offices is considerable better than in the South offices. External shading devices (instead of internal) could reduce the difference.

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Summer monitoring (3...) typical period

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.

Rooms on the North facade

0

5

10

15

20

25

30

9/25 9/26 9/27 9/28 9/29 9/30 10/1 10/2 10/3

Date

Tem

pera

ture

[0 C];

Ven

tila

tio

n [

ach

]

Text.

Air change rate

Tint.-north

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Although the indoor temperature in a room on the South facade in a normal 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.

Rooms on the South facade

0

5

10

15

20

25

30

9/25 9/26 9/27 9/28 9/29 9/30 10/1 10/2 10/3

Date

Tem

pera

ture

[0C

]; V

en

tila

tio

n [

ach

]

Air change rate

Tint.

Text.

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The CO2 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

Rooms on the North facade

-10

-5

0

5

10

15

20

25

30

9/25 9/26 9/27 9/28 9/29 9/30 10/1 10/2 10/3

Date

Tem

pera

ture

[0 C];

Ven

tila

tio

n [

ach

]

0

500

1000

1500

2000

2500

3000

3500

4000

CO

2 [p

pm

]

Tint.

Tout.

Outdoor and indoor CO2-conc.

Air change rate

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Summer monitoring (36..) typical period

During office hours the CO2 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.

Rooms on the South facade

-10

-5

0

5

10

15

20

25

30

9/25 9/26 9/27 9/28 9/29 9/30 10/1 10/2 10/3

Date

Tem

pera

ture

[0 C];

Ven

tila

tio

n [

ach

]

0

500

1000

1500

2000

2500

3000

3500

4000

CO

2 [p

pm

]Text.

Tint.

Air change rate

Outdoor and indoor CO2-conc.

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Summer monitoring (7|) typical period - ventilation rates

Ventilation rate in the summer

0

1

2

3

4

5

6

7

8

9

10

Thurs Fri Sat Sun Mon Tues Wed

Period 25 September to 1 October 1997

Air

ch

an

ge

rs p

er

ho

ur

N_day

S_day

N_night

S_night

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.

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Winter monitoring (1...) temperatures

Indoor climate in a room on the North facade

0

5

10

15

20

25

2/19 2/20 2/21 2/22 2/23 2/24 2/25 2/26 2/27

Date

Te

mp

. [°

C]

/ V

en

tila

tio

n [

ac

h]

Tint.-north

Text.

weekend

The indoor temperatures are comfortable (20 to 23°C). During the weekend, the heating power is reduced

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Indoor climate in a room on the North facade

0

5

10

15

20

25

2/19 2/20 2/21 2/22 2/23 2/24 2/25 2/26 2/27

Date

Te

mp

. [°

C]

/ V

en

tila

tio

n [

ac

h]

0

200

400

600

800

1000

CO

2 [

pp

m]

Winter monitoring (2|) indoor air quality

Tint.-north

Ventilation rate

Text.

CO2-conc.

The ventilation rate during office hours is between 3-4 ACH. This air supply leads to a good IAQ: the CO2 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.

weekend

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Major findings Thermal summer comfort:

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.

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.

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.

The Indoor Air Quality: In the summer the ventilation rate during office hours is 6-10 ach in the

summer and 4-5 ach in the winter. The CO2 concentration level is 750 ppm during office hours and 400

ppm in at other times. Hence the IAQ is good.

Thermal summer comfort: 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.

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.

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.

The Indoor Air Quality: In the summer the ventilation rate during office hours is 6-10 ach in the

summer and 4-5 ach in the winter. The CO2 concentration level is 750 ppm during office hours and 400

ppm in at other times. Hence the IAQ is good.

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Find more information on the PROBE building in the following documents:

\Reports \Monitoring Reports \Summary Reports\nl2summ.pdf global presentation of the buildings (4p./building) contents: building description - ventilation strategy and technology -

winter and summer monitoring results - conclusions

\Reports \Monitoring Reports \Detailed Reports\nl2det.pdf detailed reports of all 19 monitoring campaigns (20p./campaign) contents: monitoring set-up - analysis of results - conclusions

Find more information on the PROBE building in the following documents:

\Reports \Monitoring Reports \Summary Reports\nl2summ.pdf global presentation of the buildings (4p./building) contents: building description - ventilation strategy and technology -

winter and summer monitoring results - conclusions

\Reports \Monitoring Reports \Detailed Reports\nl2det.pdf detailed reports of all 19 monitoring campaigns (20p./campaign) contents: monitoring set-up - analysis of results - conclusions

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 ar32e301(1).exe in the directory \Installation

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 ar32e301(1).exe in the directory \Installation

Documents

The Town Hall of Zevenhuizen S.H. Liem, A.H.C. van Paassen M.Verwaal, H.F. Broekhuizen Delft, April 1998 Presentation of the building Presentation of the