Preserving sacred space: A microclimate study of the Shrine of the Bab, a Baha’i holy site

Preserving sacred space: A Preserving sacred space: A microclimate study of the microclimate study of the Shrine of the Bab, a Baha’i Shrine of the Bab, a Baha’i

holy siteholy site..

Blake Campbell & Patrick Ravines Baha’i World Centre, Conservation Office

Haifa, Israel

Shrine of the Bab Shrine of the Bab Baha’i World Centre Baha’i World Centre

Introduction Problems related to excess

moisture Monitoring Temperature &

Relative HumidityResults & FindingsConclusions


Introduction – Shrine’s current setting and environs– Structures composing the shrine

Early structures & Super structure


The Shrine of the Bab with its colonnade, golden dome, and terraced gardens.


The terraces of the shrine extending from the foot to the crest of Mount Carmel in Haifa, Israel.


Westerly view

Northerly & downward view


Formal gardens around the shrine.


Introduction – Shrine’s current setting and environs– Structures composing the shrine

Early structures & Super structure


The original structure of the shrine built by Abdu’l-Baha in 1909, half-way up the barren slope of Mount

Carmel.

_____


Original structure of the shrine in 1909.


The shrine with rooms added by Shoghi Effendi, 1939.


Rooms 1, 2, 6, 7, 8 & 9 - first construction in 1909.Rooms 3, 4 & 5 – second construction in 1939.

Floor plan


The colonnade under construction, 1950.


Workmen building the platform above the stone edifice, 1950.

The octagon with its pinnacles and balustrade, 1952.


The shrine with its superstructure completed, 1953.


Introduction Excess moisture

– Early structure– Superstructure

Monitoring T & RHResults & FindingsConclusions


Shrine of the Bab, room # 1.Widespread damage to the tile floorcaused by moisture-induced salt migration.


Room 1: Tile damage & salt deposition


Flaking & concoidal spalling of the surface and subsurface layers of the tile. Damage occurs both in the center and on edges.

Hand-sized fracture due to subflorescence.

Room 6: Tile damage


Room 8: Wall & floor moisture


Outer walls of original structure


Superstructure moisture


Where is the excess moisture coming from?

Noticed as early as 1941 and still exists.

Views & opinions:– Engineers: condensation– Custodian: underground water– Conservators: monitor & study


Introduction Excess moisture Monitoring T & RHResults & FindingsConclusions


Room 8 monitoredPeriod: ~14 months

Sensors: Hobo HO8 data loggers, T, RH & lightLoggers 1, 2 & 3 – on floorLoggers 4, 5 & 7 – 2 m high

8-bit res8Kb memT: +0.7°CRH: +5%t: 6 & 8min

http://www.onsetcomp.com/Products/Product_Pages/HOBO_H08/H08_family_data_loggers.html


Weather station on NE corner of Terrace 10 Collects:

T, RH, soil T, leaf wetness, air pressure, solar radiation, rainfall, wind speed & direction

t: every 12 minutes


Introduction Excess moisture Monitoring T & RHResults & Findings

– Time series: view all T & RH data vs. time.– Diurnal cycles: data averaged by time of day

(annual and monthly)– Histograms: Count the number of

measurements that fall within a certain range– Dew Points

Conclusions


T data of logger #4 & weather station on Terrace 10.

Building’s moderating influence on room temperature.

Temperature Time Series


Temperature Time Series

Graph (d) - data of logger 4 & weather station on Terrace 10.

Obvious trend - temperature's strong seasonal dependence.

Note building’s moderating influence on room temperature.

Room well mixed.


Logger # T mean T max T min1 21.0 28.7 13.7

2 21.2 28.7 11.8

3 21.1 27.9 12.6

4 20.8 28.3 7.8

5 21.8 28.7 12.2

7 21.8 30.3 12.6

T-10(WS) 20.9 37.3 5.6

Temperature values


RH data of logger #4 & weather station on Terrace 10. Building’s moderating influence on RH.

Relative Humidity Time Series


Relative HumidityTime Series

Graph (d) - data of logger 4 & weather station on Terrace 10.

Building’s moderating influence on the humidity.

Room well mixed.


Logger # RH mean RH max RH min1 58.4 81.0 23.4

2 59.0 81.9 23.4

3 59.7 83.5 23.4

4 64.5 95.7 23.4

5 61.7 87.3 23.4

7 60.2 89.6 23.4

T-10(WS) 75.9 99.0 11.0

Relative Humidity values


Bimodal frequency distribution for the year from October 2002 to 2003 Reflects Mediterranean climate, long summers and winters but short

transition seasons.

Annual histogram of temperature

Shrine of the Bab Shrine of the Bab Baha’i World Centre Baha’i World Centre Annual histogram of Relative Humidity


Logger RH > 60% RH > 75%# % obs Days/yr % obs Days/yr

1 53.4 194.9 2.4 8.92 54.6 199.3 4.7 17.13 55.9 203.9 9.3 34.04 71.9 262.4 21.5 78.55 65.3 238.4 10.5 38.37 59.4 216.9 8.0 29.0

Time & high humidity


Efflorescence salts: Na2CO3 & NaCl

Salts T (⁰C) RH saturation

Na2CO3 10H2O 18.5 92%

Na2CO3 10H2O 24.5 87%

NaCl 23 75.5%


Room Temp

Dew point (Calculated)


Room Temp

Dew point (Calculated)


Conclusions:Condensation – NoInterstitial condensation –

– Likely & if so, minorOther water sources –

– Ground water– Irrigation water & – Rain water


Conclusions:Further study –

– Local geological features with ground penetrating radar

– Cistern on west side

x


Thank you - Grazie

Documents

Preserving sacred space: A microclimate study of the Shrine of the Bab, a Baha’i holy site