Low Energy Housing

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Low Energy Housing

• Purple group

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Why low energy living?

• Saves the environment
• Conserves natural resources
• Saves you money

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Case study West Gorton

• Geographical information of West Gorton-
• Average wind speed at 10m agl 4.8m/s
• Average wind speed at 25m agl 5.4m/s
• Average wind speed at 45m agl 6.0m/s
• Audenshaw Reservoirs located 2 miles from West
  Gorton (currently maintained by United Utilities
  plc)
• Average daily sunshine 5 hours
• Average daily sunlight 8-12 hours
• agl above ground level

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What are the Options?

• Solar Technologies
• Heat Recovery from Drain Water
• Wind Power
• Combined Heat and Power Systems
• Microgeneration
• Geothermal Heat Pumps
• Competitor Example BedZED
• Competitor Example West Gorton
• Regulations

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Solar Panels

• Operate best when south facing and angles at
  around 30o
• No carbon emissions
• No other pollution e.g. other greenhouse gases,
  noise
• Planning permission usually required
• Panels have long manufacturers guarantees
• Very low maintenance

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PV Solar

• Polycrystalline semiconductor is more efficient
  than monocrystaline
• Typically around 12-15 efficient
• Generates electricity (useful form of energy)
• Can connect to national grid or store charge in
  batteries (potential to sell excess electricity)

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Thermal Solar

• Two types flat panels and evacuated tubes
• Evacuated tubes can operate at lower temperatures
• Refrigerant could be harmful to the environment
  if leaked from the system     

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Basic Thermal Solar System

• Works well with under floor heating
• Power is required to operate the pump (fossil
  fuel or renewable source)

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Innovative Solar Solutions

• Transparent solar cells Power Glass which can
  be applied to clear glass, plastics etc
• Mono-crystalline silicon technology allows a
  current to be produced when light passes through
  it
• Half the efficiency of current PV cells but only
  cost a quarter of the price.
• Does not affect the aesthetics of the building in
  any way unlike solar panels
• Larger area can be covered if all the windows are
  used

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Solar summary

• PV only requires daylight and not direct sunlight
• Thermal solar (evacuated tubes) can work at lower
  temperatures
• Thermal solar can reduce heating energy
  consumption by up to 2/3
• Potentially NO carbon emission for either solar
  source
• Installation costs
• PV system around 4,000- 9,000 per kWp
• Flat plate collector system is 2,000 - 3,000
• Evacuated tube systems will cost 3,500 - 4,500
• Payback periods of PV 46.4 years and Solar Water
  Heating 54.7 years
• Alternative PV transparent film applied to
  windows

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Drain Water

• Water heating is the second most demanding energy
• account 20-30 of energy consumption in homes
• There are about 80-90 of heat energy is wasted
  when the finished using hot water goes down the
  drain at home
• Drain-Water Heat Recovery System (DWHR) can
  recover heat from drained hot water used in
  showers, bathtubs, sinks, dishwashers, washing
  machines etc.

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Drain-Water Heat Recovery System

• Reduce energy needed for heating water
• Provide greater potential of water heating
  capacity, by up to 3 times
• 25 - 40 of water heating energy is saved
• Reduce GHG emissions by about 200kg/person/year
  comparing with using Natural Gas water heating

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Drain-Water Heat Recovery System

• Re-capture heat energy from waste hot water to
  preheat cold water entering other facilities
• System also designed not to lose the stored
  energy when waste cold water is flowing through
  the system
• Self cleaning design providing maintenance-free
  operation

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Drain-Water Heat Recovery System

• Recovered heat can be stored for later use
• With storage capacity heat energy can be
  recovered from any waste hot water source, such
  as dishwasher, washing machine, bathtub etc.
• System without storage capacity heat energy can
  only be recovered by simultaneous water flow,
  such as waste hot water energy from shower

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Drain-Water Heat Recovery System

• Cost of Installation and device
• About 260 - 530
• Payback range
• 2.5years 7 years
• The system typically last for 50 years or more
• System mostly using common equipments and tools,
  and the installation is relatively simple
  (installed by experienced plumber)

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Wind Power - How

• P ½ Cp?AU3
• Energy (Wind speed)3
• Placement is crucial for effective operation
• Windy places
• Utilise concentration effects

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Wind Power - Environmental

• Short energy recovery period
• Emits little CO2 in production and none in
  operation
• No fuel needed
• Very little maintenance required

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Wind Power - Economic

• Low setup cost 2500-5000 per kW
• Once installed, no costs, just FREE power
• Any energy not used can be sold back to the grid
• Contribute up to 1/3-1/2 of a households annual
  energy requirement

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Wind Power - Social

• Obvious
• Can cause shadow flicker
• Not silent (but not loud)
• Makes an obvious statement you are living
  sustainably

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Combined Heat and Power
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Combined Heat and Power - Environmental

• Emits CO2
• Requires fuel
• Uses all of the energy from the fuel

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Combined Heat and Power - Economic

• Will still cost as fuel is required
• High maintenance, will need cleaning and
  refueling often
• Pays back purchase and installation cost quickly
• Relatively cheap heat and power

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Combined Heat and Power - Social

• Can be noisy
• Emits exhaust fumes
• Can be hidden away
• Not affected by power cuts

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Pros Cons

• Pros
• All can save money
• Any excess power can be sold
• Cons
• Can produce CO2
• Can be large or an eyesore
• Most are expensive to set up

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Ground and air source heat pumps

• Extract heat from air/ground for heating
• Dump heat into air/ground for cooling
• Ground sources are a lot more efficient than air
  due to better temperature gradients
• Ground source heat pumps are therefore
  recommended over air source

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Ground source heat pumps - Environmental

• Reduce heating from burning oil, coal and
  electricity (resistance), i.e. better emissions
• Does no environmental damage in its operation
• Requires electricity to drive pump
• Refrigerants could cause damage if leaked

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Ground source heat pumps - Economic

• Cost to install 2000 5000
• Will require power for the pump
• Can save 30 - 70 on heating bills
• Can save 20 - 50 on cooling bills

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Ground source heat pumps - Social

• Safe
• Quiet
• Clean
• Socially desirable

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Other energy saving methods

• Education packs
• Insulation
• Double glazing, south facing windows
• Energy saving light bulbs
• Green mains energy supply
• Appliance power consumption monitors

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Competitor Example

• BedZED (Beddington Zero Energy Development)
• Surrey, UK

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About BedZED

• The Beddington Zero Energy Development (BedZED)
  is the UK's largest carbon-neutral eco-community
  - the first of its kind in this country
• Mixed-use, mixed-tenure development that
  incorporates innovative approaches to energy
  conservation and environmental sustainability
• 82 residential homes with a mixture of tenures

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Features

• Constructed from thermally massive materials that
  store heat during warm conditions and release
  heat at cooler times- enclosed in a 300mm
  insulation jacket.
• South facing terraces to maximise heat gain from
  the sun - passive solar gain. Each terrace is
  backed by north facing offices, where minimal
  solar gain reduces the tendency to overheat and
  the need for energy hungry air conditioning.
• Heat from the sun and heat generated by occupants
  and every day activities such as cooking is
  sufficient to heat BedZED homes to a comfortable
  temperature.
• Meters are mounted in each home and office
  kitchen so residents can keep track of usage.
• The Combined Heat and Power plant at BedZED is
  powered by off-cuts from tree surgery waste that
  would otherwise go to landfill.
• Wood is a carbon neutral fuel as CO2 released
  when burned is equal to that absorbed in the
  trees life.

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Issues to consider

• Applicability
• This development can be seen as a flagship
  development illustrating what could be done.
  However, building these as common developments
  could prove impractical. Some of the features
  from this development, highlighted previously,
  could still aid in the development of a more
  sustainable building development.

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Energy Efficient Housing Regulations

• There are no current regulations specific to
  eco housing that go beyond the regulations for
  all domestic buildings.
• There is a rating scheme available for
  constructors to demonstrate the efficiency of
  their homes to customers.

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EcoHomes Rating Scheme

• Points are awarded in 7 important areas
• A calculation of the scores from each section is
  then made to assign a rating of Pass, Good, Very
  Good or Excellent.

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Code for Sustainable Homes (CSH)

• Dec 2006
• CSH will become mandatory for public sector homes
  Apr 2007
• Will supersede EcoHomes rating system
• Rated out of 6 stars

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Energy proformance of buildings Directive (jan
2003)

• Jan 2006 deadline not met
• SAP calculation
• Home information Packs 1st june 2007, will
  include Energy performance certificate

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Energy performance certificate

• Independently assessed by approved firm
• Details homes energy and environmental
  performance
• Graded A-G, in the same way as household
  appliances
• Good grade will add to the value of a property

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Rating System

• A to C
• A is best, C is worst
• The ratings were decided by a group discussion

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Conclusions
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Recommendations

• Solar Technologies B
• Heat Recovery from Drain Water B
• Geothermal Heat Pumps B

We recommend that sustainable homes in East
Manchester should use these three technologies
based on the three aspects of sustainability,
environmental, social and economic.
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References

• http//www.segen.co.uk
• http//www.defra.gov.uk/environment/energy/review/
  
• http//www.est.org.uk/myhome/localadvice_google/
• http//www.britishwindenergy.co.uk/you/byo.html
• www.energysavingtrust.org.uk 
• http//www.dti.gov.uk/energy/sources/sustainable/m
  icrogeneration/cogeneration/page27629.html
• http//www.dti.gov.uk/energy/sources/sustainable/m
  icrogeneration/cogeneration/page27629.html
• Conversations with Nick College about his
  research
• www.greenelectricity.org
• http//files.blog-city.com/files/A05/141484/p/f/co
  generation_diagram.jpg
• http//www.neweastmanchester.com/projects/sportcit
  y/
• http//www.chrysanthemums.info/Climate/climate.htm
  
• http//neweastmanchester.com
• http//www.dti.gov.uk/cgi-bin/nre/noabl1.pl
• http//en.wikipedia.org/wiki/Audenshaw_reservoir
• www.peabody.org.uk/bedzed

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• http//www.lowcarbonbuildings.org.uk/micro/solarpv
  /
• http//www.est.org.uk/myhome/generating/types/sola
  rpv/
• en.wikipedia.org/wiki/Solar_hot_water
• http//www.nef.org.uk/greenenergy/solar.htm
• http//www.solarhomeenergy.co.uk
• http//www.greenspec.co.uk/html/energy/solarcollec
  tors.html
• http//www.homeinformationpacks.gov.uk
• http//www.diag.org.uk/
• http//www.defra.gov.uk/environment/energy/interna
  t/ecbuildings.htm
• http//www.neweastmanchester.com/
• Renewable Energy, Power for a Sustainable Future.
  Godfery Boyle (Oxford Pressfor The Open
  University, 1996)