Sustainability

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Sustainability

• Review of Sustainable Development and Low Energy
  Solutions in Construction

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Contents

• Key Areas
• Fabric and Envelope Construction
• Ventilation
• Heating
• Lighting
• Water
• Waste
• Wind
• Conclusions and Discussion.

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Sustainability, Why?

• We do not inherit this land from our Ancestors.
  We borrow it from our children.

Indian quotation
4
Design Philosophy

• Reduce
• Reuse
• Recycle
• Dispose of thoughtfully
• Design solutions must must be compliant with
  Building Regulations Part L 2006

5
Fabric and Envelope Construction

• Consideration should be given to
• Orientation
• Fabric
• Glazing
• Air Tightness
• Photovoltaic

6
Photovoltaic Cells

• Technology first used for powering satellites via
  solid-state semiconductors which generate
  electricity when exposed to light.
• PV cells can be used to replace conventional
  roofing or cladding materials such as tiles or
  natural stone.
• Energy output dependant on solar radiation with a
  range of 1,000kWh/m2 in Southern England to
  800kWh/m2 in Scotland.
• Shading, temperature and soiling can reduce
  output.
• 1m2 array will produce approx 90-110kWh/year

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Photovoltaic Cells

• Typically PV cells currently cost 280-780/m2 and
  produce between 60-130kWh/m2 of renewable energy
  per year.
• A 1 KW panel can save between 0.5 1 tonne of CO2
  emissions per year.
• Maintenance cost are low with general cleaning
  and annual inspection of the inverters being the
  only issues
• Down side manufacture of PV cell materials
  involves the use of a number of processes which
  are CO2 intensive and use hazardous materials.

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Ventilation

• Natural Ventilation
• Stack Effect by temperature difference and wind
  pressure.
• Window design to allow Trickle ventilation in
  winter, secure night time ventilation and summer
  high air change rates.

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Natural Ventilation Concept
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Heating

• Solar Panels
• Biomass
• CHP (Combined Heating and Power)
• Heat Recovery

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Active Solar Heating

• Active solar heating in the UK best suited to low
  temp heating applications, which do not require
  direct sunlight.
• Consist of solar collector, preheat
  tank,pump,control unit, pipe work, the normal hot
  water tank and a normal heating source.
• Typically solar collectors cost between
  300-750/m2 depending on the technology and would
  produce approx 300 kWh/m2 of hot water in the UK.
• A collector of approx 4-5m2 can save around 1
  tonne of CO2 emissions per year and produce a
  yield of around 1000kWh/year of heat and meet
  around half the heating cost for a typical
  domestic house.

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Heating
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Lighting

• Daylight
• - Maximising day light use
• Light Wells, Light Shelf
• Daylight Controls
• Low Energy
• Compact Fluorescent Lamps
• LED technology

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Water

• Rain Water Harvesting
• Bore Hole Water

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Rainwater Harvesting

• Water for WC flushing, cleaning and external
  irrigation can typically account for 50 of water
  use.
• Correctly collected and stored, rain water can
  meet all of these requirements, usually with no
  further treatment.
• There are no regulations prohibiting the use of
  rainwater for WCs and cleaning.
• Rainwater is soft and therefore ideal for WC
  flushing
• Some countries (e.g. Japan) now require new large
  buildings to include rainwater recovery systems

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Rainwater Harvesting
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Bore Hole Water

• Flow rates From boreholes typically 4 - 150
  cu.m / hr. (1 cu.m 220 gallons).
• Water quality Meets Environmental Standards
  required for either grey water or portable water.
• Typical usage Potable water, steam generation,
  cooling, irrigation, mineral water.
• Running costs Including licence these are
  minimal and covered within the 12 - 24 month
  payback i.e. the licence costs run from 0.5p - 2p
  per cu.m compared to 50p - 70p from water
  companies.  Electricity and water treatment costs
  must also be assessed.
• Payback 12 - 24 months typical

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Waste

• Recycling
• Organic waste products recycled through
  composting facilities
• Non-organic either reused or Stored for
  collection

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Reed Bed Drainage

• Effective treatment for grey water use
• Secondary treatment for human waste
• Septic tank used for primary treatment, standard
  minimum 10day retention.
• Out flow to reed beds with typical dwell times of
  at least 3 months
• Lime stone final filtration before reuse in the
  system.
• Settling tanks need to be pumped and cleared each
  year to maintain system function.

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Energy Crops

• Crops take the form of deciduous trees such as
  willow or Grasses such as Miscanthus (similar to
  coppice).
• The most advanced energy crop for Northern
  Europe is coppiced willow, grown on a rotation of
  2 to 4 years known as Short Rotation Coppice
  (SRC)
• After harvesting, by cutting the stems close to
  the soil, multiple shoots grow for the next
  harvest period. This cycle of harvest and re
  growth can be repeated many times.
• Fuel can be either solid or liquid based and used
  in combustion processes for electrical and heat
  generation or with the grasses as a form of
  bio-diesel.

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Wind Power

• On Shore
• Off Shore

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On Shore Wind Power

• UK is the windiest country in Europe, therefore
  Wind power is one of the most promising renewable
  energy technologies. Currently over a ¼ million
  homes are powered by this method with over 1000
  wind turbines in operation around the UK.
• Cost are site specific but current capital cost
  are around 500-750/kW, two thirds of which is
  the turbine cost. The rest being shared by
  foundations, cables and planning.
• Operation and Maintenance costs are around
  0.5p/kWh
• Typical operational efficiencies are currently
  around 95

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On Shore continued

• Machines normally placed 5-10 rotor diameters
  apart so as not to interfere with performance, as
  a result a wind farm of around 20 machines
  usually extends over 3-4 Km2.
• Global indications show that wind energy costs
  will fall because of the economies of scale. It
  is expected by 2010 that wind energy will account
  for 6 of UK electricity, although there is on on
  going debate about the effect on the UK landscape.

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Off Shore Wind Power

• Same design as on shore but the harsher climate,
  relative inaccessibility and additional cost of
  foundations reduce the viability. Therefore
  machines below 1 MW would not be cost effective.
• Typical tower height of 40-50m and rotor diameter
  of 80-100m
• Best solution for reduction in visual impact and
  the near constant availability of wind power.

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In Conclusion

• We cant solve todays problems using the same
  kind of thinking we used when we created them

Albert Einstein