interreg europe zeroco2 technology options towards nzeb (nzco2eb) for malta

Technology Options Towards NZCO2EB

2nd Semester Regional Workshop - Malta, 8th March 2017

Ing. Damien Gatt & Eur. Ing. Dr. Charles Yousif [email protected] [email protected]

Institute for Sustainable Energy

University of Malta Malta

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INTERREG EUROPE Programme

Sharing solutions for better regional policies Programme part financed by the European Union

European Regional Development Fund (ERDF) Co-financing rate: 85%/75% EU Funds; 15%/25% National Funds

Investing in your future

mailto:[email protected]

mailto:[email protected]

Factors that affect energy consumption in a building

3 Source: Reproduced from CIBSE Guide A: 2015

Human factors - comfort

Reference: http://www.hse.gov.uk/temperature/thermal/factors.htm 4

•The six factors affecting thermal comfort are both environmental and personal. These factors may be independent of each other, but together contribute to a person’s thermal comfort.

•Environmental factors: Air temperature Radiant temperature Air velocity Humidity •Personal factors: Clothing Insulation Metabolic heat

PMV and PPD

• The PMV is "an index that combines the influence of the various environmental and personal factors into the one mean value by predicting the votes of a large group of persons into one value”

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Reproduced from CIBSE KS06 :2006

PPD as a function of PMV (Fanger, 1982)

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Psychrometric chart comfort analysis (PMV/PPD Model) for Malta

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Energy Hierarchy to reaching NZCO2EB • Focus on demand reduction as a priority.

• Be Lean, Be Clean, Be Green

• Be Lean: Use less energy – reducing energy demand with sustainable design and construction principles reduces site CO2 emissions. Examples – External shading, Insulate roof

• Be Clean: Supply energy efficiently – designing building services to use energy more efficiently and use low-carbon technologies will further reduce CO2 emissions. Examples : Insulate hot water piping, use efficient Air conditioning

• Be Green: Using on-site renewable energy to complement low-carbon energy solutions will additionally reduce CO2 emissions. Examples: Install PVs

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References: http://www.1stassociated.co.uk/articles/my-house-is-too-hot.asp, http://chpblog.energ-group.com/london-calling-leading-the-way-for-greener-building-design

http://www.1stassociated.co.uk/articles/my-house-is-too-hot.asp









Correct order of choices in the NZCO2EB design process

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The correct order of choices in the design process and the impact of those on energy performance and cost - Bottom-Up Approach (Source : Reproduced from Cost Optimal and Nearly Zero-Energy Buildings(nZEB)Definitions, Calculation Principles and Case Studies J.Kurnitski (2013))

Differentiating passive vs. active design

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Passive design uses solar radiation to optimize the envelope. The plan, section, materials selections and siting create a positive energy flow through the building and “save energy”.

Passive buildings require active users (to open and shut windows and blinds…)

The basic passive design strategies

Active design uses equipment (fans, pumps) to modify the state of the building, create energy and comfort;

Source: http://www.slideshare.net/tboake/sustainable-design-part-three-the-basic-principles-of-passive-design)

Passive means of design

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The tiered approach to reducing energy requirements for COOLING:

Maximize the amount of energy required for mechanical cooling that comes from renewable sources. Adapted from Sources:

1) Terri Meyer Boake -Sustainable Design Part Three: The Basic Principles of Passive Design -https://www.slideshare.net/tboake/sustainable-design-part-three-the-basic-principles-of-passive-design?qid=41ee85ff-05f1-44c3-b776-deec800737e4&v=&b=&from_search=1 and

2) Norbert Lechner - Heating, Cooling, Lighting Sustainable Design Methods for Architects

Tier 1 (Heat avoidance)

Tier 2 (Passive cooling)

Tier 3 (Cooling equipment)

Basic building design: building shading, orientation, vegetation, reduce internal heat gains

Natural energies and passive techniques e.g. comfort ventilation and night purging

Mechanical Cooling (use energy efficient equipment) when comfort is not met using natural means (appropriately controlled)

Approach to satisfying NZCO2EB cooling energy requirements

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Cooling tier 1: Effective heat avoidance strategies for the Maltese climate Measure 1: Shading Measure 2: Spectrally selective glazing


External vs internal shading

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Reproduced from: http://erg.ucd.ie/UCDERG/pdfs/mb_shading_systems.pdf

Shading techniques

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Overhangs for south facades Limit windows on east & West facades

Movable shading Vegetation can also provide effective & sustainable shading

Adapted from Sources:



3.)http://erg.ucd.ie/UCDERG/pdfs/mb_shading_systems.pdf

Spectrally selective coatings for glazing

Solar control coatings reflect Near Infra-Red radiation (wavelength 0.78–2.5 μm) in particular, while allowing the transmittance of visible radiation and are employed in hot climates (source: Reproduced from S. D. Rezaei et al.). 16

Clear glass Glass with solar control coating

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Cooling tier 2 : Natural energies


Natural energy strategies

Malta has a very humid climate with a low diurnal temperature difference making comfort

ventilation more effective than night purging

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Enhancing comfort ventilation

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Roof ventilators

Hybrid ventilation/solar chimney incorporation to enhance stack effect ventilation

Sources: 1. Norbert Lechner - Heating, Cooling, Lighting Sustainable Design Methods for Architects 2.https://sustainabilityworkshop.autodesk.com

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Cooling tier 3 : Energy efficient mechanical cooling Measure : Reversible heat pump


Heat pump in heating and cooling mode

Source:

https://sustainabilityworkshop.autodesk.com

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Heat Pump Sources and Sinks

source: Reproduced from : Thomas Hootman - Net Zero Energy Design: A Guide for Commercial Architecture

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Heat pump types 1. Air to Air heat pumps : They are the vast majority of heat pump systems.

2. Ground source heat pumps: yearly reduction of 30–70% in electrical energy consumption for heating and cooling over air to air heat pump systems (V. Vakiloroaya et al.)

3. Water to air heat pumps : can even perform better than ground source heat pumps due to water’s high conductivity and high heat capacity.

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Water to air heat pump Ground source heat pump (source CIBSE TM51:2013)

Air to air VRF system + DOAS (source: Thomas Hootman -

Net Zero Energy Design: A Guide for Commercial Architecture)

Approach to satisfying NZCO2EB heating energy required

The tiered approach to reducing energy requirements for HEATING:

Maximize the amount of energy required for mechanical heating that comes from renewable sources. Adapted from Sources:



Tier 1 (Maximize heat retention)

Tier 2 (Passive solar)

Tier 3 (Heating equipment)

Basic building design : e.g. Surface to volume ratio, envelope U-values

Passive techniques : Direct gain, trombe wall, sun space

Energy efficient mechanical heating (appropriately controlled)

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Heating tier 1 :Maximize heat retention Measure example: Opaque thermal insulation

Approach to satisfying NZCO2EB heating energy requirements




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Thermal insulation

EPS

XPS

Vacuum insulation panels

Insulating plaster

Opaque insulation : roof and walls

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Heating tier 2 :Passive solar techniques Measure example: Direct gain, trombe wall, sun space

Approach to satisfying NZCO2EB heating energy requirements




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Passive heating

3 MAIN STRATEGIES:

a. Direct Gain

b. Thermal Storage Wall

c. Sunspace

The dominant architectural choice is Direct Gain.




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Heating tier 3 : Energy efficient heating equipment Measure example: Condensing boiler, air to water heat pump, CHP

Approach to satisfying NZCO2 heating energy requirements




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Energy efficient heating equipment

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1. Condensing boilers + low temperature terminal units 2. Air source water heat pumps

3. Combined Heat and Power (CHP) –source: CIBSE AM12:2013

Approach to satisfying NZCO2EB lighting requirements

The full energy savings for day lighting can only be harvested when a daylight control solution is installed or to some extent when personal control over electric lighting is offered to the user.

Adapted from Sources: 1) Terri Meyer Boake -Sustainable Design Part Three: The Basic Principles of Passive Design -

https://www.slideshare.net/tboake/sustainable-design-part-three-the-basic-principles-of-passive-design?qid=41ee85ff-05f1-44c3-b776-deec800737e4&v=&b=&from_search=1 and


Tier 1 (Daylight)

Tier 2 (Day lighting)

BASIC BUILDING DESIGN: Windows, glazing, interior finishes

Natural Energies and Passive Techniques: Skylights, light redirecting systems (e.g. light shelves)

Mechanical and electrical equipment: Efficient artificial Lighting with controls

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Tier 3 (Electrical lighting + controls)

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Lighting tier 1 : Daylight using basic building design Measure examples: Reflective surfaces, internal partitions


Tier 1 (Daylight)



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Daylight using basic building design

Increase surface ceiling and wall surface reflectance

Daylight potential for side lit windows as a function of window head height, room reflectance and room width

Change of partition heights Orientation and massing for daylighting

Sources: Autodesk sustainability workshop, IEA SHC task 50, CIBSE LG10:2014

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Lighting tier 2 : Daylighting (Natural energies) Measure examples: Top lighting, light re-directing systems


Tier 1 (Daylight)



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NZCO2EB Daylighting techniques

Day lighting transporting systems

Top lighting Daylight re-directing systems

Sources: Autodesk sustainability workshop, CIBSE LG10:2014, A. Tsangrassoulis: Shading and Daylight Systems (2016)

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Lighting tier 3 : Electrical lighting + controls Measure examples: LED, occupancy sensors


Tier 1 (Daylight)



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NZCO2EB Electrical lighting + controls

LEDs are the emerging technology due to their high efficiency, lifespan and satisfactory colour rendering

Electric lighting controls

Sources: IEA SHC task 50, CommONEnergy

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NZCO2EB ventilation techniques

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NZCO2EB ventilation

Tier 1: • Use natural ventilation and hybrid ventilation Tier 2: • Provide only as much fresh air as required. • Size ducting and insulate correctly to reduce heat loss and friction in an HVAC system’s air distribution system. •Use energy efficient fans.

Tier 3: • Displacement ventilation. •Use heat recovery ventilation. •Use demand- controlled ventilation (DCV). •Use free cooling.

Heat recovery ventilation

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Renewable energy systems

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Renewable Energy systems

Roof mounted photovoltaics Building integrated photovoltaics

Solar water heating (source :Planning and installing solar

thermal systems) BIPV/T

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Return of investment (ROI) for different measures

source: Adapted from NeZeh project

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Quick wins (short term ROI of 1-3 years)

• Upgrade to energy efficient lighting • Thermal insulation of boilers, domestic hot water tanks and pipes. • Proper zoning and optimise regulation of space heating and cooling. • Prevention of high unnecessary air change rate for ventilation and reduce air leakage and remove unnecessary duct bends. • Simple lighting controls for corridors • Water saving faucets • Energy auditing and proper monitoring. • Staff training •Reduce high unnecessary internal gains from equipment.

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Medium term ROI (3-8 years)

•Upgrade to high efficiency boilers •Efficient ventilation systems possibly including heat recovery • Free cooling; •Hybrid ventilation system; •Upgrade to more efficient solutions for active space cooling; •Energy efficiency rating of electrical appliances; •Energy efficient motors in HVAC applications; •Utilize waste heat of chiller; •Low temperature heating; •High temperature cooling / adaptive comfort control. •Photovoltaics assuming government grants / FIT •Solar water heating if system is properly designed, planned, managed and maintained

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Medium or Long term ROI

•Installation of sun shading devices (depending if external or internal, fixed or movable, building exposure to solar radiation); •Installation of spectrally selective solar films.

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Long term ROI (> 8 years)

•Windows changing; •Building opaque and transparent insulation; •Air to water heat pumps •Ground source heat pumps; •Water to air heat pumps; •Solar powered absorption chiller; •CHP; •Wind energy (small scale wind turbines); •Light transporting systems •Adding skylights for building retrofitting

INTERREG EUROPE Programme Sharing solutions for better regional policies

Programme part financed by the European Union European Regional Development Fund (ERDF)

Co-financing rate: 85%/75% EU Funds; 15%/25% National Funds Investing in your future