International Conference TOWARDS NET ZERO ENERGY BUILDINGS

Aalborg University (Sydhaven) , Copenhagen, Denmark Tuesday, April 30th, 2013

Session E : Lessons learned from NetZEB Annex 52 Case studies Recommended building solutions

Michael Donn & François Garde Sub Task leaders / SubTask C IEA SHC Task 40 / ECBCS Annex 52 Towards Net Zero Energy Solar Buildings TASK 40/ANNEX 52

Who we are

Prof. François Garde - Director of Sustainable

Construction Department - ESIROI, Université de la

Réunion - Coordinator IEA NetZEB STC Dr Michael Donn - Victoria University SOAD - CBPR - Coordinator IEA NetZEB STC

http://moyakarta.ucoz.ru/rastr/anti-world-map.jpg

Latitude 40

Latitude 20

Net ZEB: What is going on ?

IEA Task 40/Annex 52 Towards Net Zero Solar Energy Buildings www.iea-shc.org/task40

Target : Joint international research to advance NZEB to practical reality in the marketplace. Subtask A: Definitions and Implication (Germany/Italy) Subtask B: Design process and tools (Canada) Subtask C: Development of solution sets for different climates, building types and functions (Reunion/FRA, NZ) Subtask D: Dissemination and Outreach (Canada)

7 mandatory criteria: 30 NZEB identified worldwide so far Web data base

IEA Task 40/Annex 52 : 19 Countries involved Towards Net Solar Energy Buildings

Singapore

IEA – Task 40/Annex 52 : “Towards Net Zero Energy Solar Buildings” 19 countries involved 30 buildings Cooling Challenges;

Heating Challenges; Heating AND Cooling Challenges.

International Conference TOWARDS NET ZERO ENERGY BUILDINGS

Aalborg University (Sydhaven) , Copenhagen, Denmark Tuesday, April 30th, 2013

Pixel Schiestk-Schutzhütte

Sundays Elithis Tower

Green Office

Kyoto Highschool Limeil Brevannes

Pantin primary school

IES Cargese

ENERPOS Meridian

Daycare in Monheim

Prim. sch. in HohenNeuendorf

Lajon school

Ilet du centre

Solar XXI

CIrce

Marché international

Zero Energy Building at BCA

Plus Energy houses « weiz » EcoTerra

Riverdale

Plus energy settlement Kraftwerk

Leaf House Lima

Kleehauser

Energy Flex Family Riehen

The netZEB balance concept

Igor Sartori , Assunta Napolitano , Karsten Voss

Energy and Buildings Volume 48 2012 220 - 232 http://dx.doi.org/10.1016/j.enbuild.2012.01.032

Monitored data vs design data – Non Res

Monitored data vs design data – Res

11

Thermal comfort in hot conditions

• Two main principles: – Solar protection – Cross natural ventilation

Comfort approach Givoni zones of comfort

Building climate analysis

• Classify Temperature, Humidity, Solar, Daylight and Wind climates for the

use in generalising Solution Sets

• Initial study - traditional external climate classification did not

account for the non-residential building challenges.

Residential = Heating dominated

Non-Residential = Heating dominated

• Accounts for local climate and building standards

Climate Analysis

Site Context

What are solution sets ?

1. Building Challenge Solution Set - The set of solutions used to lower the energy needed by a particular building challenge.

2. Whole Building

Solution Set - The set of solutions used to lower the energy consumption of the whole building.

Design Hierarchy and Solution Sets

Many ‘Solutions’

Case Study - Enerpos

Passive design Solutions • Cross ventilated • Solar shading • Large windows for daylighting

Energy efficiency

Solutions • T5 lightings • Ceiling fans

Renewable Energy Solutions • PV (50 kWp)

ENERPOS on Reunion Island U-values

• Roof : 0,34 W/m2.K • Walls : 3,45 W/m2.K

BiPV Roofs 370 m²/49 kWp

Monitoring - Energy use and production

• Energy use (Net Floor Area ; Final Energy) : 14 kWh/m².y

• Production (Net Floor Area ; Final Energy) : 78 kWh/m².y

Consumption is 10 times less than a standard university building in Reunion Island

• Max load: 8 W/m² 4 times less than a standard building

• Mismatch?

ENERPOS is net zero on an annual,

monthly and daily scale

Comfort approach

Maximum allowable indoor temperature with natural ventilation and ceiling fans => 30°C

100% 97% 92% 93% 90% 93% 77% 45%

Comfort > 80% Comfort < 80%

POE - User feedback

6 case studies

Canada to Brisbane Denmark to Reunion Island Melbourne to Oslo Lisbon to Santiago Wellington to Roma Reunion Isl. to Christchurch

Solution set identification – Performance Sketch: major design ideas? – Change Climate – new solution set(s)?

Givoni Comfort Analysis – BEES template based EnergyPlus models

Performance Sketch Energy Analysis – BEES template based EnergyPlus models

PIXEL in Melbourne

Passive measures • Cooling:

• Green Roof • Solar shading • Natural Ventilation • Tinted glass

• Heating:

• Heat recovery ventilator

• Daylight systems:

• Exterior fixed solar shading

The BUILDING

Energy efficiency measures

• Artificial Lighting: 3 W/m2

• Computer Network: 4.2 W/m2

• Plug load: 10 W/m2

• Hydronic in-slab pipework in chilled ceilling

The BUILDING

Energy Generation

• PV

• Wind

The BUILDING

PIXEL in Oslo

Melbourne

Oslo

SOUTH

PV Wind Turbines

NORTH

Glazing

Shading

Night cooling

Insulation

Lighting Power Density & controls

STPV

Orientation

Ventilation

PIXEL in Oslo

Passive solutions - Re-orient - No night cooling - Double glazing - Shade transparency - Insulation - Natural ventilation EES - Increase lighting power density - Lighting controls RES - PV on the roof - Semi-transparent PV for the shading Estimated NZEB

Overheating

0

5

10

15

20

25

30

0 5 10 15 20 25 30 35 40 45

Hum

idity ratio (g water/kg dry air)

Temperature (°C)

With natural ventilation (in summer)

Energyflex : overall picture

Location : Copenhagen, Denmark 2 buildings with different activities JUST 1 BUILDING STUDIED: family house – 4 people! Net floor area per building: 216m² Ground floor: bedrooms – 1st floor: living spaces

Energyflex : original solutions set

• Passive design techniques • Volume to surface ratio: 0.55 [1/m] compact! • High insulation:

average Uopaque = 0.1 [W/m²K] Uglazed = 0.75 [W/m²K]

• Energy efficiency technologies • Floor heating coupled with ground source heat pump • Mechanical ventilation with heat recovery and coupled with heat

pump

• Renewable enegy technologies • Fixed photovoltaics • Solar thermal domestic hot water

Location change

Copenhagen, Denmark

St Pierre, La Réunion

Climatic conditions Outdoor temperature

Copenhagen, Denmark St Pierre, La Réunion

Heating dominated Cooling dominated

Not so much comfort in 1m/s zone…we have to go to 2m/s! HIGHER NATURAL VENTILATION AND CEILING FANS!

BASE CASE from DENMARK To REUNION ISLAND

% of comfort (0 m/s) 13%

% of comfort (1 m/s) 56%

Hrs of discomf. (0m/s) 7579 h

Hrs of discomf. (1m/s) 3824 h

Base case : La Reunion

Energyflex Family in Reunion New solutions set

• Cross natural ventilation, high porosity, • Ceiling fans • Large shading • High insulation of the roof (maintained) • Low thermal mass and low insulation of the

walls • No double glazing, louvres. Change of the pattern but not the shape of the building (life outside!)

Conclusions Recommended building solutions

• NZEB are narrow buildings for daylighting and cross ventilation

• Air-conditioning can be avoided

• Crucial role of ceiling fans (even for cold climates)

• Comfort, comfort, comfort

• Integration of the role of the users at the early design stage

Lessons Learned • Aim of Lessons Learned:

– Understand the issues related to the design and technologies of the net zero energy building method

• Interviewed design teams • 7 of the 30 Cases examined:

– Non-residential – Office and Education

• IDP – essential

• Energy Performance must be early goal

• Hierarchy when designing Net ZEBs : Passive Design → Energy Efficiency Systems → Renewable Energy Solutions.

• Energy end-use: office equipment 50%.

• Ceiling fans, instead of active cooling 18-30°C comfort band works in any climate when coupled with natural ventilation and ceiling fans

Ceiling fans Green Office - Paris