Space Heating

1. Space Heating

2. Heating in RdSAP • RdSAP allows you to include: • A main heating system (e.g. boiler) • An additional main heating system, (2nd main system) • A secondary heater (room heater) • The additional heating system allows two main heating systems to be included in the EPC. This means a wider variety of heating setups can be specified in RdSAP. • The secondary heating must be based on fixed room heaters e.g. gas/ solid fuel fires, electric heaters • it is not possible to select a central heating system as secondary heating.

3. Main heating • The main heating system is defined as: • A system which heats the largest proportion of the dwelling • A system which is not usually based on individual room heaters (although it can be) • A system which usually also provides the water heating • A typical main heating system would be a central heating boiler • If there is more than one heating system or device in a property use the following process to decide which is the main heating system • The main system usually provides both space and water heating and should heat at least 30% of the dwelling • If no system provides space and water heating then select the system which heats the greatest part of the dwelling • If there is still doubt then select the system which supplies useful heat to the dwelling at the lowest cost • If the costs are the same then select the system which heats the living room

4. Additional main system If a dwelling has an additional main system then the proportion of the property heated by each system should be calculated. This should be based on heated floor area to the nearest 10% • If two systems serve the same heating circuit then assume there is a 50/50 split • The main system should be the one which heats the living area • Examples where an additional main system can be used • A large property has two different boilers fitted so the whole property can be heated. One boiler is the main system the other is the additional main system. • A property has a boiler fitted to replace storage heaters, but some functioning storage heaters are left in the property, the boiler is the main system and the storage heaters are the additional system Previously only one main heating system could be entered, which restricted RdSAP and meant some properties could not be accurately modelled.

5. Secondary heating • Secondary heating must be based on fixed room heaters. • A fixed room heater is an independent heater not on a central system, such as a gas fire or electric panel heater. The heater must be fixed in place, so portable heaters are not included in the assessment. • This means it is only possible to select the following • Oil room heaters • Electric room heaters • Solid fuel room heaters • Gas room heaters • If there is more than one secondary heater in a property then use the following process to identify the heater which should be selected: • Select the type of heater which heats the greatest number of habitable rooms • If that does not resolve the choice then select the heater which is cheapest to run, based on fuel cost • If that still does not narrow it down, select the device with the lowest efficiency

6. Secondary heating • Portable heaters can be specified in particular circumstances: • When the main heating system is an off-peak storage system (this is covered later in this section) and no other type of secondary heating is present • The software will automatically include portable heaters in the EPC in particular circumstances: • If the main heating system is not deemed sufficient to heat a dwelling, and no secondary heating is specified. • If there is no heating system present in the dwelling at all • Portable heaters are defined as • Completely free-standing and self-supporting • Contains a built in fuel store, or for electric heaters, has a lead and plug • Can be easily moved between rooms • Focal point electric fires designed for the located in a fireplace can be included in the assessment as a fixed heater

7. Main Heating Types • Central heating systems • Gas boilers • Oil boilers • Range cookers • Solid fuel boilers • Electric boilers • Heat pumps • Community heating • Electric storage heating • Electric underfloor heating • Warm air systems • Room heaters

8. Types of boiler • The most common type of boiler you will encounter will be Mains Gas as is it the most widely available fuel. • The boilers will either • Regular boiler • Back boiler • Combi boiler • Condensing boiler • Combined Primary Storage Unit

9. What does a regular heating system look like • Hot water tank • Cold water tank • Feed and expansion tank • Expansion pipe- heating • Expansion pipe – hot water tank • Pump • Programmer • Room thermostat

10. Regular Boiler Key features of a regular boiler • It can provide heating and hot water for a dwelling • The hot water must be stored in a cylinder • There are usually 3 pipes coming out of a regular boiler, gas supply, flow and return) • The boiler heats water which then flows around the heating system and to the hot water tank

11. Back Boiler • A back boiler is a type of regular boiler, these are fitted behind a fire. • It provides space heating and hot water. • As with a regular boiler the water is stored in a cylinder.

12. Back Boilers • Back boilers can be • Gas, • solid fuel • Oil • In RdSAP gas and solid fuel back boilers can be identified as central heating systems • Gas and solid fuel back boilers are sometimes listed in the PCDF but not always

13. Identifying a back boiler • How can you tell if a gas fire has a back boiler? • Look for a plate at the bottom of the fire, this may come away to reveal the boiler controls • Back boilers are usually more substantial than a normal gas fire • There will usually be a control dial, sometimes with the boiler name on it • There may be a cylinder with no boiler unit

14. Solid Fuel Back Boiler

15. Combi Boiler • A combi or combination boiler provides heating in the same way a regular boiler does • It provides domestic hot water on demand, rather than storing it in a cylinder. • A combi boiler is easily identified as it usually has 5, 6 or 7 pipes. • Combi boilers also have more controls on the front of them e.g. heating, hot water and sometime a programmer

16. Combi Boiler pipework

17. What does a Combi Boiler system look like

18. Condensing Boiler • A condensing boiler is a highly efficient type of boiler • Most non-condensing boilers emit hot combustion gases, but a condensing boiler extracts the heat from the combustion gases before they are emitted, pre-warming the water in the boiler. • This means the flue gases emitted are a lower temperature • There is some condensation of flue gases as they leave the boiler, these are drained out of the boiler through a plastic condensate pipe. This is the key identifying feature of most condensing boilers • Because the flue gases are cooler a plastic flue can be used, rather than a metal flue • On a cold day you may be able to see a plume of water vapour coming from the flue.

19. Condensing Boiler pipework A. Central Heating FlowB. Domestic Hot Water C. Gas InD. Mains Cold InE. Central Heating ReturnF. Overflow/ Pressure Relieve Valve G. Condensate Pipe

20. Condensing Boiler

21. Condensing Boiler- Flue and Condensate Pipe

22. Combined Primary Storage Unit • This is an appliance which incorporates the provision of space heating and hot water; the hot water store should be at least 70L and integral to the appliance. • This type of appliance is usually floor mounted and larger than a conventional boiler

23. Underfloor Heating • Underfloor heating can be fitted to a boiler if it is fitted there will be a manifold such as the one pictured. • This manifold distributes the hot water amongst the underfloor heating loops • If both underfloor heating and radiators are present in a property it is not possible to include both as the heat emitter. Radiators should be specified as they require a higher flow temperature, making them the worst case scenario

24. Underfloor Heating System

25. Underfloor Heating System Layout

26. Underfloor Heating – Floor Construction

27. PCDF • Product Characteristic Data File • The PCDF is a searchable database which includes the following types of heating systems • Gas and oil boilers • MicroCHP* • Heat Pumps * • Solid fuel boilers * • The PCDF contains specific technical details about heating devices, including their seasonal efficiency • RdSAP software incorporates the PCDF when searching for heating systems * Covered later in this section

28. PCDF • Make sure you collect the device make and model information so you can accurately identify it in the PCDF. • If a device cannot be found in the PCDF then there is a list of types of heating systems in RdSAP, the device should be selected from this generic list, known as the alternative method in Stroma’s software.

29. Boiler ID Plate The boiler ID plate is a very useful way of finding out all the information needed to find the specific boiler in the PCDF

30. Flue Types • The flue can help identify the boiler type and it’s location. • There are a 3 flue types • Open flue • Balanced flue • Fan assisted flue

31. Open Flue • Open flues are usually found with older, floor mounted boilers • The combustion gases are taken from within the room the boiler is in. • The combustion gases are drawn up from the boiler by wind passing over the top of the flue

32. Open Flue This is the more common type of open flue, these are found on the top of converted chimneys.

33. Open Flue

34. Balanced Flue • This type of flue uses air from outside the dwelling for combustion. • It relies on natural air movement to draw the hot air back outside from the boiler • The flue must be located as close to the boiler as possible to keep the flue length short • A balanced flue is classed as ‘room sealed’

35. Balanced Flues

36. Fan assisted flue • This is a room sealed flue which uses a fan to assist the movement of the air through the flue • This means the flue doesn’t have to rely on natural air movement and can be located further from the boiler

37. Fanned Flue for Regular Boiler

38. Plastic Fanned Flue • A plastic fanned flue indicates that the boiler fitted must be condensing

39. Flue Gas Heat Recovery Flue Gas Heat Recovery Systems (FGHRS) are designed to recover heat in the flue gases discharged from a condensing boiler. • The boiler can be fired by natural gas, LPG or oil. • They use the cold temperature of the domestic cold water supply to recover extra heat that is not extracted by the boiler. • This recovered heat is used to heat the hot water supply in two principle ways: • Instantly – Recovered heat is immediately used to pre-heat to the domestic water supply before it enters the boiler or external hot water cylinder. • Deferred – Heat recovered during space heating production is stored for later use to pre-heat the domestic water supply before it enters the boiler or external hot water cylinder the next time hot water is required

40. Flue Gas Heat Recovery FGHRS can either be integral to the boiler or separate from the boiler. An integral system is known as a Passive Flue Gas Heat Recovery Device (PFGHRD), and selecting the correct boiler from the PCDF database will include the heat recovery system in the calculation FGHRS can be fitted to existing boilers, in which case the system will be separate from the boiler The FGHRS should be visible above the boiler, where the flue outlet is located. In order to include the FGHRS it must be in the PCDF

41. Flue Gas heat Recovery A flue gas heat recovery system will normally be found just above the boiler unit. Remember that the system must be included in the database in order to be included in the assessment

42. Flue Gas Heat Recovery - Software Select whether a FGHRS is present Select the fuel type Then select the FGHRS make and model information

43. Flue Gas Heat Recovery Record the standard PV data, kWp, tilt, orientation and overshading • A FGHRS can be fitted to a separate hot water store • If this is the case it may be powered by PV • Make sure you check for a solar PV array installed specifically to power the FGHRS • There is a section in the software for FGHRS and a PV array specific to it

44. Flue Gas Heat Recovery RdSAP Convention 9.06 states: • Include [FGHRS] only if found in database, identified in same way as for heating systems. When the model cannot be found no default option is available but the presence of the device should be recorded in site notes

45. Electric Central Heating • Provides heating and hot water • Generally for smaller properties such as flats • No flue

46. Electric Central Heating • This is an electric direct acting boiler • The unit is about 1metre long and can provide heating and hot water, if a cylinder is fitted • Common examples of this type of boiler are the HeatraeSadiaAmptec and the Trianco Aztec Classis

47. Electric central heating • This is an electric water storage boiler • It uses cheap rate electricity over night to heat water for space and water heating • There is a water cylinder within the unit • The cylinder must be less than 270L, if it is bigger the device is classed as a Electric CPSU

48. Electric central heating • Electric CPSU – like a gas CPSU this device has a hot water tank within the device • The water store must be over 270L for it to be classed as a CPSU, otherwise it is an Electric water storage boiler • These units are generally quite large, around 1.8m tall so will be found in cupboards. Electric CPSU

49. Electric central heating • Electric dry core storage boiler ; this works in a similar way to storage heaters, using cheap rate electricity to heat bricks inside the unit • The heat is transferred from the bricks to water via a heat exchanger to provide space and water heating

50. Solid Fuel Boiler • These can be either manual or auto (gravity) feed • Solid fuel boilers run on traditional solid fuels such as anthracite, or they can run on biofuels such as wood pellets • Solid fuel boilers are usually regular boilers capable of providing heating and hot water for a property.