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RLC2013

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by

Justin Zarb

on 27 February 2014

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Transcript of RLC2013

Retrofitting Social Housing
for
Low Energy Comfort

Passive Techniques
The Maltese Climate
Running Mean Temperature
(based on the last 8 Days)
Temperature
Relative Humidity (%)
Diurnal Temperature Range
Variation 1988-2012

Average Diurnal Variation
2008-2011
EN15251
Indoor environmental input parameters for design and assessment of energy performance of buildings- addressing indoor air quality, thermal environment, lighting and acoustics.
Building Performance: Energy or Comfort?
The Problem with the
Chamber Model
`
The diurnal temperature range is the difference between maximum and minimum daily temperatures. It is an important factor which determines passive cooling strategies.
Is the climate Changing?
Ta' Giorni Social Housing Building
via: http://weatherspark.com/
via: http://weatherspark.com/
via: http://weatherspark.com/
Dewpoint Temperature
Hours of Sunlight
via: http://weatherspark.com/
Cloudcover
via: http://weatherspark.com/
Predominant Winds
via: http://weatherspark.com/
PMV = (0.303e-0.036M+0.028) {(M-W) – 3.05 x 10-3[5733-6.99 (M-W) –Pa] - 0.42[(M-W) – 58.15] – 1.7x10-5M(5867-Pa) - 0.0014M(34-Ti) - 3.96x10-8fcl {(Tcl+273)4-(Tmrt+273)4 – fclhc(Tcl-Ti)}

Predicted Mean Vote
Hot
Warm
Relatively Warm
Neutral
Relatively Cool
Cool
Cold
Metabolic Rate
External Work
Partial Water Vapour Pressure
Indoor Mean Temperature
Mean Radiant Temperature

Convective heat transfer coefficient between the occupant and the environment

Global Events
EU Legislation - Towards 2020 targets
Maltese Law
Energy-Driven Policy
VS.
Adaptive Thermal Comfort
External Temperature
Internal Temperature
Comfort Temperature
Adaptive Comfort in
EN 15251
Predicted
Actual
Adaptive Comfort Temperature
(90% acceptable within the range +/- 2.5 degrees)

No account of
cultural
,
climate
and
social contextual

dimension of comfort.

Relies heavily on
mechanically ventilated systems
to provide thermal comfort

The methodology used for judging thermal sensation is

unnatural
.



There is still no known way of expressing
air velocity
and
mean radiant temperature

in relation to outdoor temperature

The Adaptive approach
tends to push the
thermal comfort zone
of building occupants to its
critical boundary
.

Present day
Energy use in Maltese dwellings is the lowest per household in comparison to all other European countries. Unless adjustments are made, it is likely that actual heating and cooling in a number of buildings is lower than predictions based on PMV and related plant profiles.
Behavioural Adaptation
Perceived Comfort
Building Adaptations
Lower limits of Adaptive Comfort boundary in EN 15251
ASPECTS OF THE BUILDING
Temperature & Humidity Sensors
INTERNAL TEMPERATURES
4 bedroom apartment: 77sqm

3 bedroom apartment: 70sqm
Recommendations
Dynamic Simulation
D: Wednesday 17th April
t: 08.15-09.00
T: 19.8 degrees (ambient air temp.)
o: West
BUILDING FABRIC
Mean indoor Temperature
External Temperature
Adaptive Comfort Temperature (EN15251)

Upper adaptive comfort limit

Indoor Temperature
Lower Comfort boundary
Qualitative Questionnaire (Summer 2012)
Quantitative Questionnaire (Winter 2012/13)
Which are the hottest rooms in the house?
Where are the fans?
Do you perceive any natural ventilation?
How hot or cold do you feel from 0 to 3?
If you could, would you change the temperature?
Is the temperature acceptable?
Second-hottest Room
Hottest Room

f Fan location
NEUTRAL
HOT
COLD
100% ACCEPTABLE
PREFERRED
TEMPERATURE INCREASE
N
Keeping Cool in Summer
Keeping Warm in Winter
Keeping Cool in Summer
Keeping Warm in Winter
SOLAR EXPOSURE
FANS AND AIR CONDITIONING
HEATERS
WIND VELOCITY AND PRESSURE
HIGH PRESSURE
LOW VELOCITY
Temperature (degrees celcius)
Cooling (August 2012)
150-200 Degree days above 24-25 degrees
<40 Degree days above 90% Comfort Zone
What happens when the thermal comfort category is changed?
At 0.5toe/dwelling, Malta has the lowest energy consumption per dwelling in Europe (ADEME, 2012).

(It is, however, on the rise)
What is the Thermal Comfort and how is it calculated?
The Heat Balance Approach
aka.
The Engineers' Approach
sufficiently accurate for room temperatures below 27 degrees C, for air velocities less than 0.2m/s and relative humidity below 60% (Charles, 2003)
P.O. Fanger, 1970
EBPD
THERMAL MASS
INSULATION AND DOUBLE GLAZING
RADIANT COOLING
SURFACE COLOUR (ALBEDO)
EVAPORATIVE COOLING
NATURAL VENTILATION
NOCTURNAL COOLING OF THERMAL MASS
COMFORT VENTILATION
REMOVAL OF INTERNAL GAINS
Assumptions
Weather file
Window opening profiles
Occupancy profiles
Airflow due to leakages
Material properties
Ventilation Strategy
Window Closed
Window Open
Window Closed
Window Open
Window Closed
Window Open
External Temperature
External Temperature
External Temperature
Internal Temperature
Internal Temperature
Internal Temperature
Also Dessicant Cooling
RELIABLE WEATHER FILES


ADAPTIVE COMFORT MODEL FOR THE MALTESE ISLANDS


MATERIAL PROPERTIES LIBRARY

OPERABLE INSULATION


ENHANCED NATURAL VENTILATION


DESSICANT AND DOWNDRAUGHT COOLING SYSTEMS


RADIANT COOLING OF NIGHT AIR VIA THIN SHEET RADIATORS

THANKS

Prof. Vincent M. Buhagiar
B.E.&A.(Hons),M.Sc.(Lond.),Ph.D.(Wales),Perit

Dr Simon P Borg
B.Eng.(Hons)(Melit.),M.Sc.(Lough.),Ph.D.(Strath.)

Prof Alex Torpiano
B.E.&A.(Hons),M.Sc.(Lond),Ph.D.(Bath),D.I.C.,M.I.Struct.E.,C.Eng.,Eur.Ing.,Peri
t

Prof Robert Ghirlando
B.Sc.(Eng.),M.Eng.,Ph.D.,F.I.Mech.E.,Eur.Ing


Ing. Charles Yousif,
B.Sc.(Hons)(Mech.Eng.),M.Phil.,Eur.Ing.


Perit Herman Calleja

Ing. Mario Ellul

All the residents of Block C, Ta' Giorni

Periti
Antoine Camilleri
Melanie Spiteri
Andre Pizzuto
Stephen Mangion
Ray Vassallo

Chamber Model
Heating (January 2013)
150-220 Degree days outside 24-25 degrees
<130 Degree days outside 90% Comfort Zone
20%-26%
59%-86%
Comfort Range in Ta' Giorni
Roof Insulation
Internal & External Insulation
Double Glazing
Shading
One’s satisfaction with an indoor climate is achieved by matching the
actual thermal environmental conditions
prevailing at that point in time and space with one’s
thermal expectations
of what the indoor climate should be like. (Yao, Li, & Liu, 2009)
Microclimate
Roof
Windows
Walls
Shafts
Full transcript