Bioenergy Home Heating Options

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Bioenergy - Home Heating Options

• George Estcourt

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Overview

• Why we heat our homes
• Types of heating systems
• Heating fuels
• Why biomass is good

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Why we heat our homes

• Short, but definite, winter season
• World Health Organisation recommends 18oC
• Timber-framed homes can reach 13oC or lower in
  winter
• Insulation alone is not sufficient
• A warm, dry home is a healthy home
• Home temperatures under 16oC can cause health
  problems

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Home heating systems

• Under-floor heating using hot water heat transfer

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Home heating systems

• Wall-mounted radiators
• Hot water boiler

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Home heating systems

• Ducted hot air
• Hot water boilers
• Hot air furnaces
• Heat pumps
• Electric

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Home heating systems

• Central heating
• Under-floor heating (new home)
• Wall-mounted radiators (retrofit)
• Ducted hot air (retrofit)

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Point source heating systems

• Wood/log fires
• Gas fireplaces
• Wood pellet fireplaces
• Electric heaters
• Heat pumps

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Heating fuels

• Gas, LPG/natural gas convenient (if available)
• Firewood - labour intensive
• Wood pellets convenient (if available)
• Coal - .
• Diesel convenient (if available)
• Electric, heat pumps/radiant - ultra convenient

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Why is biomass a great heating fuel

• Wood-based fuels are well distributed
• Carbon neutral/sustainable
• Relatively cheap
• Low emissions?

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How to improve those wood burning emissions

• Install high-efficiency burners to reduce waste
  heat
• Only burn seasoned firewood
• 20 m.c. 14.5 GJ/tonne
• 40 m.c. 10.3 GJ/tonne
• Do not smother your fire
• Cut firewood into smaller pieces (10-15cm
  diameter)

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Firewood vs. Wood pellets

• Dry Pine firewood
• Moisture content 20 wet basis
• Density 250 kg/m³
• Fuel value 14.5 GJ/tonne
• Cost 320/tonne - 80/m³
• 2 tonne (8m³) per year 640/year

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Firewood vs. Wood pellets

• Wood pellets
• Moisture content 8 wet basis
• Density 650 kg/m³
• Fuel value 18 GJ/tonne
• Cost 475/tonne
• 1.66 tonne/year 791/year

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How the fireplace effects the fuel consumption

• Modern wood fireplace
• 65 efficiency
• Modern wood pellet fireplace
• 90 efficiency
• The more efficient the heating source, the less
  fuel needed to heat your house

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Who gets more heating for their dollar

• Wood pellets 90 efficiency
• 1.66 tonnes of pellets
• 26.9 GJ or 7470 kWh output
• 10.5 cents/kWh
• Pine firewood 65 efficiency
• 2 tonnes of firewood
• 18.85 GJ or 5236 kWh output
• 12 cents/kWh

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Conclusions

• All biomass is good as long as its burnt well
• Most efficient burners
• Best quality fuels
• Biomass can be used for
• Direct heat
• Hot-water boilers
• Ducted air
• Electricity production

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Any questions?

• Visit Bioenergy Knowledge Centre
• www.bkc.co.nz
• Log a job
• 0800 bioenergy
• Email me
• george.estcourt_at_scionresearch.com