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cooling ceramics
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Cooling with Porous CeramicThe use of porous ceramic for passive evaporative cooling in buildings
Dr Rosa Schiano-Phan, 1 June 2009
School of the Built Environment
Cooling with Porous CeramicThe use of porous ceramic for passive evaporative cooling in buildings
Use of porous ceramic in the tradition
Recent developments and research
Manufacturing process
Building integration of porous ceramic systems
Cooling Performance
Muscatese Window system
Cooling with porous ceramic in the tradition
Mashrabiya and window systems in Egypt and Sicily
Wind-catchers in Iran and Iraq
Wind-catcher and Maziara water jar in Egypt (1970-80s)
Improved Iranian Wind Tower (1980s)
Pabellon de Espana, Zaragoza Expo 2008
Architect: Francisco Mongado
750 clay columns over shallowwater body
Passive Evaporative Coolingusing porous ceramic
EVAPCOOL Research project
Low cost - low maintenance cooling system
No risks of microbiological contamination
Simple System with Standardised Components
Large wet surface areas available to evaporation
Water reservoir with small volume to surface ratio
Principle of operation in perimeter rooms
OUT IN
Ceramic Evaporators
b) Wind-catcher
a) Cavity Wall
Fan
Manufactured by Elsa Ceramiche, Florence, IT
Porous Ceramic Components
Ceramic Manufacturing Processes
Pressing
Casting
Drawing/Extruding
Casting in Chalk Moulds
CLOSED MOULD OPEN MOULD
Properties of cast ceramic
Plastic properties
High level of porosity
Uniform distribution of mechanicaland physical properties on thewhole surface
Silica
Kaolin
Low FiringTemperature
Porosity: Volume of pores over volume of the porous solid in %
Apparent Porosity True Porosity Permeability f(h, p)
P = (W-D)/(W-S) x 100
W: Weight of Wet specimenD: Weight of Dry specimenS: Weight of Specimen inwater
Properties of cast ceramic
Casting Production Cycle
Storage of row materials Mixing of row materials(feldspar, kaolin, silica)
Casting in Chalk Moulds: Filling & Drying
Thickness depends on: Time Temperature Hygroscopic property of chalk Raw materials
30% water
20% water
Casting in Chalk Moulds: Emptying
Water content 12-15% Ready for extraction
Casting in Chalk Moulds: Manual Extraction
Complex operation Compromise mechanical prop. Easier for open mould Closed multiple parts mould
requires opening beforeextraction
Low firing T to assurehigh porosity
Glazing is avoided topreserve permeability
Casting in Chalk Moulds: Firing & Finishing
Casting in Chalk Moulds: Development of prototype
Development of prototype: Design studies
Porous ceramic cooling system: assembly options
STACKED OPTION
CANTILEVERED OPTIONHUNG OPTION
Generic Integration of the Evapcool systems ina typical office building
Performance - Case Study Building:Apartment Block in SW Seville (1958-64)
FLAT A
FLAT D
B
C
CO
RR
IDO
R
BEDNW
BEDW
BEDS
LIVINGROOM
KIT
CH
EN
A
DLIVINGROOM
KITCHEN
BEDS
BEDS
BEDN1
BEDN2
BEDN3
Performance Analysis:Temperature profile for a typical summer day
Indoor and Ambient Temperatures for representative hot day
16
18
20
22
24
26
28
30
32
34
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Hr
C
DBT Ambient Supply T 0.03m3/s
Frequency of indoor Temperatures exceeding 28oC in summer(Jun-Aug)
43.0
27.7
77.9
44.5
27.3
72.9
0102030405060708090
NV only NTV only PCS & NTV
%
DBT RT
(Occupied time when DBT above 28degC for One Day Simulation = 29%)
Air Movement and T distribution
Temperature Plots PPD PlotsS
ING
LE
SID
ED
VE
NT
ILA
TIO
NE
VA
PO
RA
TIV
EC
OO
LIN
G
Peak T: 32degC
Peak T: 27degC PPD: 5%
PPD: 37-70%
Conclusion
Porous Ceramic Evaporators can be integrated in existingresidential buildings in perimeter cavity wall construction;
The proposed system can meet residual cooling loads of typicalapartments where a number of mitigation techniques can beadopted to improve comfort conditions and building performance;
The system can reduce peak air temperature of about 6-7degC andimprove the U-value of existing walls (from 1.3 to 0.3W/m2.K);
The system is more effective at higher ventilation rates and theposition of inlets has an impact on comfort;
Annual energy savings up to 31kWh/m2 can be achieved in a typicalapartment and CO2 savings of 18.5 Tonnes/yr in the whole building.
Further developments Sketch ideas:Coolwall
Coolwall idea
+
= &
Coolwall prototype pattern
Promotion and Dissemination ofPassive and Hybrid Downdraught Cooling
in Buildings
PHDC Project:
Post Occupancy Evaluation of case study buildings aroundthe world
Market assessment
Design Sourcebook & Simplified Performance AssessmentTool
Symposia & Workshops in EU, China, India: next in Malta on25-26th June 2009
Website: www.phdc.eu
Thank you!
rosa.schiano-phan@nottingham.ac.uk
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