Ground source heat pumps extract heat from the ground through a ground loop system to provide heating for buildings. Solar thermal panels collect heat from the sun which is then used to heat water and store it in a hot water cylinder. Biomass heating uses biological materials like wood to provide a low-carbon source of fuel for heating. Passivhaus is a construction standard that emphasizes maximizing insulation, minimizing thermal bridges and air leakage, and using renewable energy sources to provide comfortable, energy-efficient buildings.

1. Renewable Heat / Passivhaus
Gary Wilburn
Sustainable
Construction
Network

2. Heat - generating low
and zero carbon technologies

3. 1. Ground source heat pumps (GSHP)
I Ground remains at a fairly constant temperature (10-12°C)
all year round at approximately 1.5 meters below the
earth’s surface.
I GSHP extracts heat from the ground to provide space
(and water) heating to any building type.
I Air source and water source heat pumps are also available.

4. GSHP: three main elements
1. Ground loop. - Comprised of lengths of pipe buried in the ground,
either in a borehole or a horizontal trench.
2. A heat pump. - Evaporator - Compressor - Condenser.
3. Heat distribution system. - Under floor heating or radiators
for space heating and in some cases water storage for hot
water supply.

5. Ground loop
I Water (or other fluid) is circulated through pipes underground
and passes through a heat exchanger that extracts heat
and is circulated through a building (often underfloor heating,
fan coils or oversized radiators).
I Pipe work containing heat transfer fluid is either laid in
‘horizontal trenches’ or in a ‘vertical borehole’ and transfers
the heat from the ground to be used for space or water heating.

6. GSHP Efficiency
I The efficiency of a GSHP system is measured by the coefficient of performance (CoP)
I CoP= ratio of ‘units of heat energy output’ for ‘each unit of electricity used’ to drive
the compressor and pump
I Typically every unit of electricity used to pump the heat, 3-4 units of heat are
produced. Therefore, typical CoPs range from 3 to 4

7. 2. Solar water heating
Solar thermal hot water
I Converts energy from the sun to provide useful heat. Their most
common application in the UK is to provide hot water
I Comprises of a collector with a heat transfer fluid mounted on the
roof of the building. This fluid is heated by the sun and the heat is
transferred by a heat exchanger to a separate water storage tank
or a twin coil hot water cylinder inside the building, which is used
to provide hot water

8. Solar thermal hot water: components
1. Solar panels
Collect heat from the sun's radiation and are usually fitted
on the roof
2. Heat transfer system
Uses the collected heat to heat water
3. Hot water cylinder
Stores the hot water that is heated during the day and supplies it for use later

9. Solar thermal hot water: types of system
1. Flat bed panels
- Realize temperatures of 35ºC
- Good for supplying pre-heated water for a gas boiler
or immersion heater
- Commonly used and cheaper technology
2. Vacuum tube
- Suited to cooler climate due to reduced heatloss
- Can heat water to 60ºC. May require no additional heating
- Should be linked to a storage facility to store excess
warmth in summer for winter season.
- More expensive though generally claim to provide better
winter performance

10. 3. Biomass heating
Any biological mass derived recently from plant or animal matter, including:
I Material from forests (roundwood, cutting residues and other
wood brashings)
I Dedicated crop-derived biomass (woody short-rotation
coppice energy crops – willow and poplar, grass
crops-miscanthus, timber crops)
I Dry agricultural residues (straw, poultry litter) and:
I Wet waste (slurry, silage), food wastes, industrial and municipal waste

11. Biomass: Low carbon source of fuel
I Biomass is considered carbon neutral or low carbon if
materials are derived from sustainable sources.
I Some net emissions result from cultivation, harvesting,
processing and transportation of fuel.
I Local availability of fuel is important for reducing
associated net carbon emissions.

12. Lifecycle Carbon Emissions comparison
I These figures include raw material supply, production,
transport, energy generation and eventual disposal
I Biomass more efficient when used for space heating
as compared to electricity generation
I Solid Biomass for heating typically gives reductions
of about 90% as compared to fossil fuels

13. Passivhaus United Kingdom

14. Passivhaus – a comfort standard?
I No draughts
I No cold radiant
I No summer overheating
I Fresh air always
I Whole house warm - no hypothermia
I Fuel Poverty eliminated

15. Passivhaus – Simplicity
I Extra insulation
I Extra panes of glass
I Full ventilation system
I And clever design…
- Site layout
- Insulation and thermal bridges
- Solar gain and protection
- Air tightness and ventilation

16. Retro-fit housing...
I Passivhaus targets for a retro-fit home
I Prewett Bizley Architects
I 22 kWh / m2 achieved
I Victorian terrace
I MVHR and air tightness challenges
I Owned by a Building Physicist!

17. Culford Road London

18. Batschuns House Austria

19. Sourcing sustainable products & technologies

20. Building Materials Showroom Austria

21. Building Materials Showroom Austria

22. Case studies: Designing to a higher level

23. Passivhaus School Austria

24. Passivhaus Construction
I Use of bioregionally sourced materials
I Manufactured, high quality solution
I Off-site modular format
I Maximising insulation, minimising energy use
I Known technology and construction details

25. Ludesch Community Building Austria

26. Wolfort Housing Austria

27. Swimming Pool Dornbirn Austria

28. Wolfort Housing Switzerland

29. Swimming Pool Dornbirn Austria

30. Sohm Factory Switzerland

31. York stone barn retro-fit
I Low carbon conversion
I HPW designed
I GSHP
I Triso super 10 insulation
I POE study ongoing
I Listed exterior
I Owner living through building works

32. Domestic retro-fit (before)

33. Charts created using heating system data created Elevation G (NORTH 1)
by DSM in IES and lighting data
Domestic Retro-fit (after)

34. Paultons Park
Working closely with the client team at Paultons, HPW have created
a low carbon, wild flower roofed and naturally ventilated indoor
play area
The building will form the centre piece to the new attraction at the well
known amusement park for ‘Peppa Pig’ and his friends. With underfloor
heating, wind catchers, super insulated building shell, rainwater harvesting,
hybrid frame and locally sourced timber cladding the 10,000 sq.ft facility
is due to open in spring 2011

35. Paultons Park Site progress

36. Paultons Park Site progress

37. Thank you... any questions
Sustainable
Construction
Network