Environmental Technology Systems Awareness Learning Tool

1. Environmental Technology Systems Awareness Learning Tool Enter

2. Environmental Technology Systems Awareness Welcome Welcome to the ‘Environmental Technology Systems Awareness’ learning tool which is one of four learning tools that have been developed by the Skills for Climate Change project. How to use this tool The main way to navigate around this tool, use the forward and back arrows in the bottom right corner of each screen. In some areas of the tool a set of icons similar to those below will appear for you to select from. You can click on the icon from anywhere in the tool to access the module menu page.

3. Introduction Welcome to the ‘Environmental Technology Systems Awareness’ learning tool. The purpose of the tool is to enable you to develop a fundamental knowledge of micro-renewable energy and water conversation technologies . The aim of the learning tool is to : • develop your understanding of the fundamental working principles of micro-renewable energy and water conservation technologies • enable you to recognise the top level regulatory requirements that apply in relation to micro-renewable energy and water conservation technologies installation • enable you to recognise the fundamental requirements of building location/building features for the potential to install micro-renewable energy and water conservation systems to exist. • enable you recognise the typical advantages and disadvantages of micro-renewable energy and water conservation systems Please note: This learning tool is not intended to develop the occupation competence to design or install micro-renewable energy and water conversation technologies. The information and illustration provided is limited to awareness only. The diagrams provided only contain the relevant technical detail for awareness purposes and must not be used as installation diagrams.

4. When is it appropriate to install environmental technology systems? Before we move onto the rest of the tool, it is important to understand the role that environmental technology systems have in helping to address climate change and improve sustainability. Before considering the installation of environmental technology systems it is essential that approaches to reduce demand and to improve efficiency are taken first . 3 2 1

5. Learning Tool Overview This learning tool includes four modules: To enable you to gain a good overall awareness and understanding, It is recommended that you study all four modules; however, the modules can be studied in any order. Each module includes points. It is recommended that you complete each learning check before you move on. To begin, click on any module above.

6. Module 1: Heat Producing Technologies

7. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems • Objectives At the end of this section you will: • understand the fundamental working principles of solar thermal hot water systems • recognise the top level regulatory requirements that apply in relation to solar thermal hot water systems installation work • recognise the fundamental requirements of building location and building features for the potential to install to a solar thermal hot water system to exist • recognise the typical advantages and disadvantages of solar thermal hot water systems 

8. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Basic System Categories • Although there are a number of system types, variations and configurations, solar thermal hot water systems fall into two basic system categories: • passive systems • active Systems In passive systems, the system circulation takes place by the natural thermosiphon or convection process. For this process to work the solar collector needs to be mounted below the storage cylinder. As this arrangement is not as practical in the UK as it is in warmer countries, the majority of systems installed in the UK are ‘active’ systems where the system circulation takes place due to the inclusion of a circulating pump.

9. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems - Indirect Active System (with Twin-Coil Cylinder) Click on each number for a brief overview of the purpose of the system component 1 2 5 3 4 Please note that due to the intended purpose of this learning tool, some system components are not shown. This is not an installation diagram.

10. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Direct Active Systems In direct solar hot water systems, the domestic hot water that is stored in the cylinder is directly circulated through the solar collector. This type of system can be added to existing hot water systems, but it is essential that all system components are compatible with the system design. For example, as the domestic hot water is circulated through the solar collector it is not possible to add anti-freeze protection to the system water – therefore some components such as the solar collector need to be freeze tolerant. Please note that due to the intended purpose of this learning tool, some system components are not shown. This is not an installation diagram.

11. Module 1: Heat Producing Technologies Solar Thermal Hot Water System Components - Solar Collector Sometimes referred to as a solar panel, the collector is mounted in a suitable location (usually on a roof). The collector absorbs the sun's energy and uses it to heat the heat transfer fluid within the system. Types of Solar Collector ‘Evacuated Tube’ Solar Collectors ‘Flat Plate’ Solar Collectors

12. Module 1: Heat Producing Technologies Solar Thermal Hot Water System Components - Differential Temperature Controller The Differential Temperature Controller (DTC) is the heart and brains of the system. Linked to high level and low level temperature sensors the DTC only allows the system circulating pump to operate when there is: solar energy available there is a demand for water to be heated

13. Module 1: Heat Producing Technologies Solar Thermal Hot Water System Components - Circulating Pump The circulating pump circulates the system heat transfer fluid which is either water or glycol depending upon the type of system, around the solar hot water circuit. The operation of the circulating pump is controlled by the Differential Temperature Controller

14. Module 1: Heat Producing Technologies Solar Thermal Hot Water System Components – Auxillary Heat Source In the UK, solar thermal hot water systems require an auxillary heat source to heat the stored domestic hot water when there is either: insufficient solar energy to heat the water fully; or no solar energy to heat the water Where a space heating system is installed, the boiler typically provides the auxillary heat source for the solar hot water system. Where there is no space heating the auxillary heat source is typically an electric immersion heater

15. Module 1: Heat Producing Technologies Solar Thermal Hot Water System Components – Storage Cylinder The storage cylinder stores the domestic hot water and allows for the heat transfer from the solar collector circuit to the stored domestic hot water. A popular cylinder type is the twin coil cylinder. This type of cylinder incorporates a lower solar heating coil and a higher auxillary heating coil. Some cylinders will also include a shunt pump to circulate the stored water in the cylinder when just the auxillary heat coil is in operation One of a number of alternative arrangements is to use a separate solar pre-heat cylinder as shown below. This arrangement is less common.

16. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems Click here to reveal Click here to reveal Click here to reveal Click here to reveal How did you do?

17. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Regulatory Requirements • The installation of a solar thermal hot water system will require compliance with a number of regulatory requirements including health and safety, water regulations, electrical regulations. A competent installation contractor will have a detailed knowledge of these regulations and will ensure compliance. • Within this section we consider two primary regulatory requirements in relation to solar hot water systems: • Building Regulations • Town and Country Planning Regulations • Note: The requirements stated in this section relate to England and Wales only. The requirements for Scotland and Northern Ireland may differ.

18. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Regulatory Requirements The Building Regulations (England and Wales) comprise of 14 parts. Seven of these parts may have relevance to solar hot water systems installation. Click here to reveal Click here to reveal Click here to reveal Click here to reveal Click here to reveal Click here to reveal Click here to reveal

19. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Regulatory Requirements • Town and Country Planning Regulations – Building Mounted Collectors • The installation of a solar hot water system collector array is typically classed as permitted development for houses and bungalows providing : • the solar collectors are not installed above the ridgeline and do not project more than 200mm from the roof or wall surface. • the solar collectors are sited, so far as is practicable, to minimise the effect on the appearance of the building • the solar collectors are sited, so far as is practicable, to minimise the effect on the amenity of the area. • the property is not a listed building* • the property is not in a conservation area or in a World Heritage Site The Local Planning Authority should be consulted for clarification, particularly for installations to flats and non-dwelling building types. *Listed Building Consent may be required even if planning permission is not required.

20. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Regulatory Requirements • Town and Country Planning Regulations – Stand-alone Collector Arrays • The installation of a stand-alone solar hot water system collector arrays is typically classed as permitted development providing : • The array is no higher than four metres • The array is sited at least 5m from boundaries • The size of array is limited to 9m2 or 3m wide and 3m deep • The array is not being installed within boundary of a listed building • In the case of land in a conservation area or in a World Heritage Site the array will not be visible from the highway. • Only one stand-alone solar installation is being installed. *Listed Building Consent may be required even if planning permission is not required.

21. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems - Building location and feature requirements • For the potential to install to a solar thermal hot water system to exist, as a minimum some or all of the following building and location factors will need to be considered: • orientation of the solar collectors • tilt of the solar collectors • adjacent structures or obstructions that introduce overshading • the availability of a suitable solar collector mounting structure • compatibility with any existing hot water system

22. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Collector Orientation In the UK, we tend to relate a south facing garden in our homes to the availability of the most sunshine throughout the day. Well the same applies in relation to solar hot water systems. The ideal orientation is south facing. Orientations between south east and south west will also provide good results. For buildings with suitable east and west facing roof areas, a split collector system is possible with solar collectors mounted on both east and west facing roof slopes.

23. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Solar Collector Tilt As well as orientation, the ‘tilt’ of the solar collector is also key factor that determines the amount of solar energy that is transferred from the sun to the solar hot water system. Collector ‘tilt’ is the angle that the solar collector is mounted from the horizontal plane. Where a pitched roof already exists, the tilt is typically determined by the roof pitch. Where there is no pitched roof available, it is possible to mount solar collectors on vertical and horizontal surfaces. Solar collectors may also be mounted on purpose built support frames to provide the required tilt. However, this type of installation typically requires more design consideration and consultation with product manufacturers etc.

24. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements We have identified that the building orientation and collector tilt are key factors in determining the amount of available solar energy that is transferred from the sun to the solar hot water system. Now let’s examine some data…. Annual solar radiation kWh/m2 (Source: Table H2, SAP, 2009) What is the optimum orientation and tilt given in the table above? Click on the forward arrow to check your answer

25. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Annual solar radiation kWh/m2 (Source: Table H2, SAP, 2009) The optimum orientation and tilt given in the table above is south facing at a 30o tilt. Typically, a collector tilt of between 30o and 40o from horizontal is considered to be very close to optimum with 35obeing optimum.

26. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Overshading Any overshading of the solar collector(s) will have an impact on how much available solar energy that is transferred from the sun to the solar hot water system Based upon Table H4, SAP, 2009

27. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Suitable Collector Mounting Structure • The collector mounting structure must be suitable in terms of being: • of sufficient size (m2) • typically a minimum of 3- 4m2 of suitable collector mounting area is needed with approximately 0.75m2 to 1m2 of collector area being required per person • strong enough to support the collectors • as well as considering the the potential for collapse or damage to the structure under normal conditions, wind uplift loads must be considered and assessed. • in good condition • there is no sense in installing a solar collector to a roof that is in a poor state of repair. Any repairs or refurbishment should be carried out prior to installing the solar collector(s)

28. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – building location and feature requirements Compatibility with any Existing Hot Water System Existing hot water systems come in various types and configurations. Three types of systems are shown below: Point of use systems and instantaneous centralised systems are not normally suitable for use with solar hot water systems. However, some combination boilers are compatible with solar pre-heated water. Product manufacturer’s instructions should always be consulted for advice.

29. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems Click here to reveal Click here to reveal Click here to reveal Click here to reveal How did you do?

30. Module 1: Heat Producing Technologies Solar Thermal Hot Water Systems – Advantages and Disadvantages Some example advantages and disadvantages are: Well Done! You have now completed the solar hot water systems section. Click on the forward arrow to return to heat producing technology system menu page

31. Module 1: Heat Producing Technologies Heat Pump Systems Objectives At the end of this section you will: • understand the fundamental working principles of a heat pump unit • know the common types of heat pump unit • know the types of heat emitters that are suitable for heat pump system installations • recognise the top level regulatory requirements that apply in relation to heat pump systems installation work • recognise the fundamental requirements of building location and building features for the potential to install heat pump systems to exist • recognise the typical advantages and disadvantages of heat pump systems 

32. Module 1: Heat Producing Technologies Heat Pump Systems What is a heat pump? A heat pump is a device for converting low temperature heat a to higher temperature heat Some heat pumps can also work in reverse and convert high temperature heat to a lower temperature So how does a heat pump work? ………………

33. Module 1: Heat Producing Technologies Heat Pump Systems How does a heat pump work? Most heat pumps make use of the mechanical vapour compression cycle commonly known as the refrigeration cycle to convert heat form one temperature to another. The heat pump refrigeration cycle works on a similar principle to a domestic refrigerator but in reverse. Let’s look at how the heat pump refrigeration cycle works ………………

34. Module 1: Heat Producing Technologies Heat Pump Systems Heat pump refrigeration cycle 1. The low temperature heat (heat source) enters the Evaporator which is a heat exchanger . A refrigerant on the other side of the evaporator is at a cooler temperature than the heat source and heat is transferred from the source into the refrigerant causing the refrigerant to evaporate. 2. The now gaseous refrigerant enters the compressor, resulting in a rise in the temperature and pressure of the refrigerant. 3. The refrigerant continues its course through the Condenser (which is also a heat exchanger) transferring the higher temperature heat to either an air or water distribution circuit (often referred to as the ‘heat sink’ or emitter circuit). 4. The refrigerant, now at a cooler temperature, enters the expansion valve, which reduces its pressure and temperature to its initial state at the evaporator. The cycle then repeats itself.

35. Module 1: Heat Producing Technologies Heat Pump Systems How efficient are heat pumps? Heat pumps are classified as a ‘low’ carbon technology because they need some electrical energy to operate. Depending on the application, operating conditions and type of heat pump utilised, heat pump energy output can be 300% to 500% more than the electrical energy input. Heat Pump efficiency is referred to as Coefficient of Performance (COP) In its simplest form COP relates to heating output divided by the electrical power input. For this example the COP is 4.0, calculated as follows: Heating output (4kW) ÷ Electrical power input (1kW) = 4.0

36. Module 1: Heat Producing Technologies Heat Pump Systems Heat pump technology can convert low temperature heat from an air, ground or water source to higher temperature heat for use in ducted air or piped water ‘heat sink’ systems. The type of heat pump unit must be selected in relation to the intended ‘heat source’ and ‘heat sink’ arrangement’ Let’s now look at the options in more detail………….

37. Module 1: Heat Producing Technologies External Air Source Heat Pump System Options A variety of heat pump system arrangements are possible using the external air as the heat source. Air source heat pump will typically operate at temperatures up to -20 oC. Air source heat pumps can be single internal units that receive the incoming air through an inlet duct that passes through the external wall of the building . An popular alternative is the use of an external fan coil (evaporator) unit that is linked to an internal unit. Fan coil units can be noisy and this need to be considered at the design stage. Let’s now look at the ground source options ………….

38. Module 1: Heat Producing Technologies Ground Source Heat Pump System Options A variety of heat pump system arrangements are possible using geothermal ground heat as the heat source. A variety of closed (sealed circuit) collector loop arrangements can be used. SlinkyTM type collectors (illustrated) are sometimes used where available ground area (m2) is limited. External ground source heat pump units (not illustrated) are also available. Let’s now look at some more ground source options ………….

39. Module 1: Heat Producing Technologies Ground Source Heat Pump System Options An alternative to horizontal ground collector loops is a vertical collector loop installed in a borehole. This type of installation requires a specialist drilling rig to be used to create the borehole. A specialist contractor is normally used to undertake the drilling operation. Vertical borehole collector loops are often used where the geothermal conditions support the use of a ground source heat pump but where the available ground area (m2) is limited. Click on next for more ground source options ………….

40. Module 1: Heat Producing Technologies Ground Source Heat Pump System Options An ‘open’ vertical borehole ground collector loop is an alternative to a ‘closed’ vertical borehole ground collector loop. With this arrangement , two boreholes are used and the collector circuit is open and the collector circuit fluid flows naturally from the open ended return pipe to the open ended flow pipe. . This type of arrangement requires the availability of a suitable geothermal water source. Click of next for water source collector circuit options ………….

41. Module 1: Heat Producing Technologies Water Source Heat Pump System Options Where a suitable water source exists such as a lake or a pond, this can be a very effective alternative to a ground source collector circuit. For illustration purposes the SlinkyTM type collector is shown in a vertical position, but water source collectors are simply laid on the bottom of the lake or a pond and weighted as necessary to keep them in place. ‘Open’ water source collector circuits (not illustrated) are also an option.

42. Module 1: Heat Producing Technologies Heat Pump Systems Click here to reveal Click here to reveal Click here to reveal Click here to reveal Click here to reveal How did you do? Let’s now look at the ‘heat sink’ emitter circuit options ………….

43. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuits One of the factors that affects heat pump system efficiency is the temperature difference between the heat source and the heat sink. The closer the temperature between the heat source and the heat sink circuit, the better the Coefficient of Performance. Traditional ‘wet’ heating systems that incorporate a condensing boiler use a mean (average) water temperature of approximately 70oC. A heat pump system mean water temperature will typically be between 30oC and 40oC The lower mean water temperature dictates that some types of heat emitter and hot water storage cylinder are more suitable than others for use with heat pump systems.

44. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options 4 1 3 2 Heat pumps using a piped Water ‘Heat Sink’ Circuit can be used to heat domestic hot water storage vessels (1), underfloor heating circuits (2), radiators (3) and fan convector heaters (4). However, some of these are more suitable than others. Click on each number for more information and when finished click on next

45. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options Domestic Hot Water Storage Heat pumps can be used to heat a domestic hot water storage cylinder. Standard type indirect hot water storage cylinders are not suitable for heat pump system due to the size of the heat transfer coil. A ‘tank-in-tank’ hot water cylinder is the most appropriate for use with heat pumps. Some heat pump units have an integrated ‘tank-in-tank’ cylinder. The ‘tank-in-tank’ design provides a large surface to surface contact between the heating circuit water and the stored domestic hot water. This design is very suitable due to the lower temperature of the heating circuit water in a heat pump system when compared to a traditional boiler-fed heating system. A ‘boost’ or auxillary heater is required to boost the stored water temperature to standard 60oC domestic hot water storage temperature ‘Tank-in-Tank’ Hot Water Cylinder

46. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options Underfloor Heating Underfloor heating systems operate at a lower mean (average) water temperature than a heating system with radiators. Therefore, underfloor heating is very suitable for use with heat pumps.

47. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options Panel Radiators Standard type panel radiators are designed to work at a mean (average) water temperature of approximately 70oC. A heat pump system mean water temperature will typically be between 30oC and 40oC To be effectively and efficiently used with a heat pump system, standard type panel radiators would need to be significantly over-sized to enable the required heat output to be achieved using a lower mean water temperature . This factor means that heat pump units are typically less suitable for use with existing standard type panel radiator circuits that have been sized for a mean water temperature of 70oC. Low temperature, high efficiency panel radiators are available and these are more suitable for use in a heat pump heat sink circuit. Where low temperature, high efficiency panel radiators are used, the Coefficient of Performance will typically be lower than if underfloor heating is used.

48. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuit Options Convector Heaters Natural and fanned convector heaters are suitable for use with heat pumps. As is the case with low temperature, high efficiency panel radiators, where natural and/or fanned convector heaters used, the Coefficient of Performance will typically be lower than if underfloor heating is used. Fanned Convector Heater

49. Module 1: Heat Producing Technologies Heat Pump System Piped Water ‘Heat Sink’ (Emitter) Circuits Buffer Tanks Some heat sink circuits make use of a component called a buffer tank. In basic terms, a buffer tank is a vessel that accumulates and stores heating circuit water ready for use when needed. Heat pumps are not designed or sized to meet short-term heat loads. For efficient operation a heat pump heeds to be able to start-up and run for a period of time. Stop-start operation can also shorten the life of the heat pump compressor. Buffer tanks are also useful where an auxillary heat source such as a boiler is being used with a heat pump. This type of system is known as a bivalent system. Most air source heat pumps, particularly those with an external fan coil unit need to defrost regularly. Buffer tanks are also useful to provide heat for the defrost cycle.

50. Module 1: Heat Producing Technologies Heat Pump Systems – Regulatory Requirements • The installation of heat pump systems will require compliance with a number of regulatory requirements including health and safety, water regulations, electrical regulations. A competent installation contractor will have a detailed knowledge of these regulations and will ensure compliance. • Within this section we consider two primary regulatory requirements in relation to heat pump systems: • Building Regulations • Town and Country Planning Regulations • Note: The requirements stated in this section relate to England and Wales only. The requirements for Scotland and Northern Ireland may differ.