St' Ninian's Cathedral

1
St. Ninian's Cathedral

• Preserving The Future

2
Background

• The entire cathedral was painted by Ozias LeDuc
  in 1899-1902
• The majority of his original art work was painted
  over in 1937
• The church is looking into a costly restoration
  of the Ozias LeDuc paintings

3
Background

• The interior of the cathedral was last painted in
  1989
• At the time, the painted surface was properly
  prepared before the new paint was applied
• A few years later the interior paint began to
  peel more rapidly in some areas than others

4
Project Definition

• St. Ninian's Cathedral
• Main focus on the peeling of paint
• Requirements
• Find an effective solution for the problem of the
  peeling of paint incorporating Electrical and
  Mechanical Engineering components
• Provide a good cost estimate
• Goal
• To provide a resonable solution that is practical
  and cost effective for the cathedral

5
Art in St. Ninians

• Frescos by Ozias Leduc
• Oil on dry plaster.
• These are not as durable as those painted on wet
  plaster

6
Peeling Pant

• There are two ways in which paint peels
• Total film failure
• All layers of paint are peeling
• Inter-coat failure
• One or more coats separate from a lower coat
• This occurs at St. Ninians

7
Causes of Peeling

• Poor surface preparation
• Incompatible paints
• Moisture
• Poor Adhesion

8
(No Transcript)
9
Research on Deformation

• Study was Done on Russian Cathedrals
• Walls composed of plaster
• Same as St.Ninians Cathedral
• Temperature deformation
• Temperature increases the body becomes larger
• Humidity deformation
• Bodies absorb moisture from the air and become
  larger
• Humidity deformation is more serious than the
  deformation due to temperature changes

10
Deformation

• Deformation curve of wall face in Russian
  Cathedral
• Y. Tabunschikov and M. Brodatch Indoor air
  climate requirements for Russian churches and
  cathedrals, Indoor Air 2004 14 (Suppl 7) 168174

11
Recommended Range

• Janeen Renee Ault, ENVIRONMENTAL REQUIREMENTS FOR
  MUSEUMS, Thesis in Mechanical
• Engineering 2000 (64-65)
• ASHRAE recommendations for the Temperature and
  Relative Humidity
• Maximum ranges are highlighted in gray

12
Required Humidity

• According to this deformation curve
• Most favorable humidity zone is between
• 40-60
• Optimal Parameters
• Reduce variation of humidity
• Temperature not to be controlled
• Range between 15C to 25C is acceptable
• Relative humidity between 35-65
• Current Conditions
• 20C and 34

13
Explanation of the Problem

• Attic humidity very high
• Humidity transfer from high to low
• Damaging to cathedral

14
Locating the Source

• What is the source of paint peeling?
• Crawlspace
• Square beams covered in circular plaster
• Cross section of column
• Air flow through main columns from crawl space
  below cathedral
• Higher concentration of peeling on walls directly
  above steam leak is evidence for the problem
  being caused by the steam
• Leak has been repaired

15
Cross-section
16
Side View
17
Ventilation For Main Body

• Mechanically run
• Two separate systems at each end of the church
• Pulls air out of choir loft and above the altar

18
Ventilation In Attic

• Vents in the attic work with the mechanically run
  system
• Controlled by a thermostat that is manually set

19
Control

• The Ventilation in the attic is turned on by a
  thermostat
• The thermostat sends a signal to an actuator
  which opens the damper to the attic and closes
  the damper to the main body

20
Proposed Improvements to Ventilation

• More fresh air intake
• Automated control

21
Past Improvements

• Insulation
• Recently upgraded to R-40
• Repaired walkway in the attic
• Makes the attic more accessible

22
Ventilation System Control
Talon Control System
23
Control System

• Software manages and controls the entire system
• System only needs to be monitored
• Collects data from the sensors

24
Sensor Details

• All sensors measure temperature and humidity
• Why temperature and humidity sensors?
• provides a better spectrum of the problem area
• set bounds for temperature and humidity

25
Relative Humidity (RH)

• Definition
• Measure of amount of water vapor in the air
  compared to how much it can hold at that
  temperature
• Relative Humidity is directly related to
  temperature

26
Sensor Placement

• Attic
• 4 Sensors
• 2 Equally spaced along upper section
• 1 placed centrally in each lower section

• Duct work
• 7 sensors
• 1 in each end of the ducts

27
Attic Sensor Placement
28
Sensor Placement

• Above Choir Loft
• and Altar
• 2 sensors
• 1 placed central to choir loft
• 1 placed central above altar

• Main Body
• 2 sensors
• Each placed centrally at top of interior walls
  with arches

29
Main Body Sensor Placement
30
Sensor Placement

• Crawlspace
• 3 sensors
• 1 between storm door and replaced valve
• 1 central to crawlspace
• 1 at south end

31
Crawlspace Sensor Placement
32
Automated Control

• Located on the ventilation system
• Turns system On/Off
• Adjusts fan speed
• Done with variable frequency drive
• Controlled by the system control computer

33
Advantages

• Reduce need to enter the attic
• More effective temperature control
• The choir loft
• Near the altar
• Provide information on critical areas via
  constant data logging
• Can alert if a system component malfunctions

34
Disadvantages

• High initial cost
• Initial system control training required
• Requires some technical understanding

35
Estimated Cost
36
Meeting With Neil van Rossum

• Presented information

• Neils response

• Gave a rundown of entire project
• Explained the research done and knowledge gained
  to support solution
• Changes in approach from start to finish

• He believes we have approached the problem
  correctly
• Every engineering problem must be thoroughly
  investigated before a solution is executed

37
Additional Comments

• The crawlspace is the only obvious source of
  humidity
• Neil said that what we have done is made a
  designed proposal
• Furthermore implementing a long term monitoring
  system is an excellent idea because it allows
  future parties to use stored data to study trends
  

38
Website

• http//www.stfx.ca/academic/engineering/DesignProj
  ects/Winter2008/welcome.html

39
Questions?
40
Acknowledgements

• Ken Farrell
• Steve Gaudon
• Andrea MacDonald
• Bruce Sparks
• Tom Roach
• Elaine MacLean
• Father Tom
• Matthew Mattie
• CJ MacLellan
• Neil van Rossum
• Harry Daemen
• Mike Byrne