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