Efficient use of energy simulation in
the
early design phase
Pierre Jaboyedoff, Partner
With contribution from
Kira Cusak
Sorane SA
Architectural and climatic control systems
choices
The design of high performance buildings
require the use of modern simulation
tools. Presentation of the use of different
simulation tools in the process of
designing high performance bioclimatic
buildings.
Simulations integrating buildings and
systems are the only way to guarantee the
expected results.
Simulation tools allow studying the
interaction between the environment and
the building with the HVAC and other
passive and hybrid systems
?
Example of applications of sophisticated tools
during the integrated design process
No wind
the f irst level of fices are correc tly coole d The higher of fic es are not sufficiently cooled 600 W /m2 at 11h00 SOUTH facade Paradox of high energy performance Energy efficient buildings and systems:
“The simpler and
more bioclimatic
the buildings are,
the more complex
the design process
is”
More sophisticated
design tools needed
Systemic analysis”
Example:
•Radiant cooling, slab cooling •Natural and hybrid ventilation systems
Solar protections and natural ventilation
The use of high performance solar protection
systems combined with high inertia and natural
ventilation allow to reduce significantly the
cooling requirements even in some of the Indian
climates
Interior blinds
SHGC > 40%
External movable
blinds
SHGC < 10%
Movable blinds
inside double
facade elements
SHGC < 12%
Study of the optimal shape, facade HVAC systems,
and SPV for a high rise building in Paris
Option 1: Square deep floor plate (2000 m2), poor envelope, nodynamic solar shading device, mechanical ventilation without heat recovery (reference case for comparison with typical existing high rise building) 38m 60 postes de travail 1065 m2 SHON 27 m Plan libre Espace fermé Réunions Box individuel Reprographie Sanitaires Locaux techniques Ascenseur
Option 2: Square deep floor plate (2000 m2), good quality envelope, dynamic solar shading device (Solar gain coefficient = 15%), mechanical ventilation with heat recovery, natural ventilation on the peripheral zones (Compact high performance building)
65m 18 m Plan libre Espace fermé Réunions Box individuel Reprographie Sanitaires Locaux techniques Ascenseur 69 postes de travail 1189 m2 SHON
Option 3: shallow floor plate (2000 m2, 130 m width, 15.4 m depth), good quality envelope, dynamic solar shading device (Solar gain coefficient = 15%), mechanical ventilation with heat recovery, natural ventilation on the peripheral zones (Shallow plate “bioclimatic” design)
36m 25m 53m 1 9m 1 3m 13,8 3m
Option 4: shallow floor plate (2000 m2, 130 m width, 15.4 m depth), good quality envelope, dynamic solar shading device (Solar gain coefficient = 15%), mechanical ventilation with heat recovery, natural ventilation between peripheral and central zones (Shallow plate “bioclimatic” design with cross ventilation)
1 5m 16,5 m 13m 15m 47m 11m 26m 44m
TRNSYS parametric model developed specially for such studies
(including HVAC, photovoltaic panels on the facade)
Turn Radiation Nat. vent. Cooling Shading+Light Weather data Ps ychrometrics Sky temp Light Thresholds Lights Shading N Shading S Shading E Shading W Building Temperature Power Schedules _lighting Equa-kJ_per_hr_to_kW 28b-OU1 28b-OU2 Type55 Type55-2 25c-OU4 25c-OU5 25c-OU7 25c-OU8 Equa-Generator Type65d-vent-Light Type65d-Front Mec Vent type_965_lighting Equa-Pers ons -PC HVAC333_1a Ventil-Return Equa_light_s ummary Sumofheatcool Equa-sommes Type94a_Front Type94a_Back Type94a_LeftType94a_Right
Type22-Front Type22-Left Type22-Right Type22-Back
Type2b Type22-Center
Equa-Control-VentNat
Parametric generator for studies with a tool
like TRNSYS
Development of specific tool allowing parametric
studies by varying quickly parameters like:
o Geometry of the building
o Windows to wall ratio
o Glazing and dynamic shading characteristics
o Natural ventilation, mechanical ventilation, hybrid systems
o HVAC system choices, heat recovery, …
o HVAC system performances
o Passive and hybrid systems and combinations
o …
Energy performance index of the 4 options
Energy Performance index of an existing
tower
Measured Energy Balance (Final Energy: 2007)
o EPI: 43 kWh/m2-yr
OFS Tower, city of Neuchâtel 2007
50.0 60.0 70.0 80.0 90.0 100.0 /m 2 -a n
Elec. Technical devices Elec. Lightning + PC’s Elec. Heating+Ventilation Cold Heat
Primary energy of the 4 options
Net primary energy requirements
Study of the optimal facade design for a high
rise building
Analysis and comparison
of the performance of
different natural
ventilation systems of
openings including
lamella movable blinds in
the double facade
elements by
Computational Fluid
Dynamics simulation
Analysis of the wind distribution
(direction, speed frequency)
CFD modelling of the façade system
with offices
Movable lamella
blinds between
double glazing
inside and single
glazing outside
Automatically
controlled natural
ventilation
openings
Option 1: Openings through slot
(initial architectural proposition)
Option 2: openings
through horizontal rain
protection screens
(optimised solution)
Option 1: Openings through slot (initial
architectural proposition)
Volumes where the temperatures is
above 26 °C are filled with orange
color
Option 2: openings through horizontal rain
protection screens (optimised solution)
Volumes where the temperatures is
above 26 °C are filled with orange
color
Example of a study on how to efficiently reduce cooling needs
in new residential buildings in the composite climate of India ?
Concept study for the development of guidelines
TRNSYS MODEL OF TYPICAL APARTMENT
NATURAL VENTILATION, INCLUDING SCHEDULES AND REGULATION OUTPUTS POWER TEMPERATURE DEVICES INCLUDING SCHEDULES OF USE CEILING FANS OVERHANGS AND FINS LIGHTING EXTERNAL AND INTERNAL BLINDS WHEATHER FILES ORIENTATION EXTERNAL AND INTERNAL BLINDS WHEATHER FILES ORIENTATION EXTERNAL AND INTERNAL BLINDS
WHEATHER FILES NATURAL VENTILATION,
INCLUDING SCHEDULES AND REGULATION ORIENTATION EXTERNAL AND INTERNAL BLINDS WHEATHER FILES OUTPUTS POWER TEMPERATURE NATURAL VENTILATION, INCLUDING SCHEDULES AND CONTROLS ORIENTATION EXTERNAL AND INTERNAL BLINDS WHEATHER FILES AIR CONDITIONERS
03/11/2011 29
PASSIVE DESIGN SOLUTIONS
Findings > Passive Design Solutions
03/11/2011 30
OPTIMISED PASSIVE DESIGN SOLUTION
Findings > Passive Design Solutions
EFFICIENT & ALTERNATIVE ACTIVE COOLING SOLUTIONS
1) New generation High Performance Air Conditionner with Improved Condenser
2) High Performance Air Conditioner with Evaporative Condenser
Findings > Passive Design Solutions > Active Cooling Solutions
EFFICIENT & ALTERNATIVE ACTIVE COOLING SOLUTIONS
1) With AC with Improved Condenser , 33% savings on the cooling load
2) AC with Evaporative Condenser, 48% savings in the cooling load
3) Two Stage Indirect Adiabatic Cooling, 40% savings in the cooling load
03/11/2011 33
OPTIMISED ACTIVE COOLING SOLUTION
Findings > Passive Design Solutions > Active Cooling Solutions
03/11/2011 34
COMBINATION OF ALL PASSIVE AND ACTIVE SOLUTIONS
Findings > Passive Design Solutions > Active Cooling Solutions > Combined Passive and Active Solutions
Conclusions
High performance building design requires high performance
software tools to be able to assess by simulation at an early
design stage:
o The building architectural features
• Solar protections (movable exterior or in double skin blinds) • Natural ventilation
• ….
o The HVAC systems
• Slab cooling • Radiant panels
• High performance chillers integrating part load operation
• ….
o The hybrid systems
• Passive and hybrid cooling systems • (adiabatic, two stage/indirect adiabatic) • Underground earth tunnel
• Vertical thermal underground heat exchangers and storage effect
• ….
