- The document discusses the HeatPod project, a whole-house retrofit by Penwith Housing Association to dramatically reduce the carbon emissions and energy use of an existing home. - The retrofit included external wall insulation, triple glazed windows, an energy efficient heat recovery ventilation system and a ground-source heat pump installed in a conservatory addition called a "HeatPod". - Initial results showed the home's carbon emissions reduced to around 17kg CO2/m2/year and space heating has not been needed so far, with the internal temperature maintained at 18 degrees Celsius using just the heat pump system.

1. The PHA HeatPod project Presented by Denys Stephens Sustainability Manager Penwith Housing Association – a member of Devon & Cornwall Housing group Winner of the National Home Improvement Council’s ‘ Best Local Authority and Registered Landlords Completed Modernisations’ Award 2011 Part of

2. Manages 6000 homes throughout Cornwall Extensive programme of energy efficiency works since the 1990’s – reduced stock CO2 by 50% Pioneered GSHPs in UK social housing Won a project in the Retrofit for the Future Competition Penwith Housing Association A member of the Devon & Cornwall Housing Group

3. Whole house retrofit

4. Reasons for retrofitting existing homes 80% reduction in CO2 required by 2050 Proposed 30% EU emissions cut by 2020 Peak oil – fossil fuels running out Energy costs and security of energy supply Homes generate 27% of UK’s CO2 emissions 80% of the homes we will be using in 2050 are already built To meet 80% reduction target emissions from existing homes must be eliminated

5. Whole House retrofit issues: New challenges in the use of technology and in project management Occupied homes? How to improve thermal performance of building fabric? – methods need to suit dwelling type Minimise carbon emissions from space & hot water heating Air tightness & controlled ventilation Low energy lights & appliances

6. What is whole house retrofit? A package of improvement measures designed to reduce energy use and CO2 emissions to a minimum Applies low carbon standards required for new homes to the existing housing stock Addresses most features of a home that waste energy Measures will vary according to the existing features of each house – no standard solutions Requires energy modelling to ensure reliable cost effective results – using SAP or PHPP Fabric measures are applied first, followed by renewable energy technologies where needed.

7. Retrofit for the Future – Whole House Approach To create exemplar houses both in terms of energy efficiency and comfort, it is necessary to consider the retrofit of housing in a holistic manner that recognises houses are systems that are interdependent upon the technologies deployed within them and the people that occupy them. Retrofit for the Future will therefore take a ‘whole house’ approach to develop and demonstrate whole house solutions that deliver deep cuts in energy use and carbon emissions, high levels of comfort and attractive costs.

8. Retrofit For The Future competition Government competition managed by the Technology Strategy Board 80 % reduction in carbon emissions – reframed as: 17 kg CO2 /m2 / year (SAP 2005) Whole house primary energy target 115 kWh/m2/yr Creating 87 exemplar super low carbon homes in the UK Innovation, research & development a key requirement Replicability extremely important Detailed energy modelling essential – SAP 2005 with whole house spreadsheet or Passive House Planning Package

9. Very high but practical standard of insulation & air tightness based on PHA experience Includes active heating – some households need greater warmth than totally passive systems can provide Innovative GSHP system providing very low carbon heating meeting the 17 kg/m2/year RFFF target HeatPod Project – concept:

10. High level of insulation & air tightness using tried & tested systems fitted externally to minimise internal disruption HeatPod – a multi-purpose free standing conservatory providing solar gain, covered clothes drying and extra space, but also fitted with most of the M&E equipment Ground / air / solar source heat pump using energy from exhaust air & HeatPod solar gain to enhance system performance 1 kW grid connected PV system HeatPod Project – features:

11. HeatPod Project - Plans 100 mm external Wall insulation Softwood triple glazing Wood pellet stove High performance External doors

12. HeatPod Vertical Section MVHR system augmenting GSHP performance Pressurised hot water cylinder Ground source heat pump Ground loop circulating pump Concept drawing

13. Project start event – October 2010

14. Installing Monitoring System

15. Drilling GSHP Borehole

16. Installing the PV System

17. New triple glazed windows and Energy efficient external doors

18. Window Detail

19. Preparing walls for insulation

20. Fixing External Wall Insulation - 1

21. Fixing External Wall Insulation - 2

22. Fixing External Wall Insulation - 3 Adding reinforcing layer Ground floor edge insulation

23. External Wall Insulation completed

24. Installing the HeatPod -1

25. Installing the HeatPod -2

26. Ground / Air / Solar Source Heat Pump Ground Loop Circulating Pump Box (outside HeatPod) Ventilation / Heat Recovery Unit Ground / Air / Solar Source Heat Pump Hot Water Cylinder Heat Pump

27. Energy Flow Diagram airflow airflow airflow Incoming air warmed by solar gain in HeatPod MVHR Ducts (red) MVHR Unit – transfers recovered heat to ground loop Radiator system – inputs heat from heat pump when needed Ground loop (not to scale) provides energy for GSHP but also acts as a thermal store for recovered heat Passive air inlet system (green) Highly insulated and airtight structure (thermal mass inside insulation)

28. Kitchen Modified to accommodate low energy appliances

29. Living room New wood pellet secondary heating

30. Loft 400mm additional mineral wool insulation Passive air supply routed through loft

31. Completed House Street view Garden view

32. Design & project management: Penwith Housing Association Ltd (DCH Group) Design partners: Earth Energy Engineering (Penryn) and Mimer Energy Ltd. (Falmouth) Main Contractor: Mears Ltd (Penzance office) HeatPod / Conservatory: Causeway Trading Group, Hayle . M & E Contractor: M V Clatworthy Ltd, Hayle. External Insulation & rendering: Keith Towsey, Truro. PV System: Plug Into The Sun, Penzance. Wood Pellet Stove: The Stove Shop, Liskeard. HeatPod – A showcase of Cornish expertise:

34. Internal air quality improved by MVHR system All domestic hot water provided by heat pump system – 2 kW hrs/day (25-30 pence). 25% more efficient than standard GSHP House internal temperature so far around 18 degrees C – without space heating (which has not been needed up to November 2011 owing to mild weather) HeatPod – Key results so far:

35. Data modelling by John Parker Consulting HeatPod Project – CO2 emissions

36. Data modelling by John Parker Consulting HeatPod Project – fuel costs

37. Acknowledgements The work reported here has been funded by the Technology Strategy Board under the Small Business Research Initiative (SBRI) under the Retrofit for the Future programme. This project is one of nearly 90 projects funded under the programme. Further information on the programme can be found at: www.innovateuk.org/retrofit Thanks for listening! Special thanks to the following for supply of equipment: Calorex Ltd, NIBE Energy Systems Ltd, E.ON, Currys.