1. INSULATION

2. Thermal insulation
Thermal insulation works by providing a thermal barrier which slows down the rate of heat transfer or temperature change.
Generally thermal insulation is divided into two main areas:
Thermal insulation of buildings
Thermal insulation of building services (i.e. of pipes and technology devices)

3. A. Reasons for buildings insulation
A decrease in energy consumption of buildings is related to additional buildings insulation. There are many reasons for insulating buildings to achieve energy savings and to obtain good working conditions. Other reasons are:
To reduce heat losses
To provide thermal comfort
To conform to standards
To provide condensation control

4. Other saving opportunities
As well as additional insulation of buildings, there are other possibilities for saving energy:
change windows
use of passive solar (e.g. continuously occupied rooms to be on the south side of the building; large areas of glass on the south side of the building)
However, because of high investments both can only be considered when renovating the building.

5. Analysing the current state of insulation
The main reason to analyse the current state of the insulation is to reduce the energy bill.
Analysing building insulation includes
outdoor walls
transparent constructions (windows, doors, glass panels)
roofs
floors
Cellars

6. Visual inspection
Staff and the Energy Manager will normally know the building they are working in and its weak points. Plans with detailed information about the construction, the age of the building and the materials used will normally be available and give an initial overview on the current situation.
However, if no information is available it might be helpful to inspect the building in a systematic way. The following aspects should be looked at:
Roof
Condensation
Presence of mould
Thermo camera

7. 1.Roof
In countries with cold winters, see if snow remains on the roof. If it melts but remains on the roofs of other buildings this is probably due to heat loss through the roof because of inadequate, or even no, insulation in the roof space.
Additional insulation of the roof is necessary.

8. 2.Condensation
Condensation occurs when warm air comes into contact with cold surfaces.
Look for areas of damp on external walls, water on internal window sills.

9. 3.Presence of mould
Mould and mildew occurs in damp areas. This damp may be due to condensation but also to water penetration.
The solutions for elimination of condensation and mould are
Additional insulation
Provide appropriate heating
Provide adequate ventilation

10. 4.Thermo camera
Thermo imaging helps to identify insulation gaps and cracks. This does not determine exactly the amount of emitted heat but shows the most critical places on a building envelope. It would then be possible to meter the exact heat transfer. The principle of this measurement is in scanning of the infrared radiation emitted from the building surface.

11. EXAMPLE – Thermo image
Example of a thermo image. Notice that different temperatures are in different colours. Pic 12_1Thermo.jpg

12. Measurement and calculation
Another way to analyse the energy consumption in buildings is
to measure the outside temperature and the energy consumption
to calculate the consumption

13. Measure the outside temperature and the energy consumption
Although not specifically for analysing building insulation ET curves can be an indicator of the building insulation. The ET curve relates the heating consumption with outside temperatures. The lower the outdoor temperature, the higher the energy consumption

14. Bench marks for heating
Another indicator for evaluating the insulation is a comparison of the energy consumption with bench marks. For example in Central Europe the bench mark heating consumption is 70 kWh/m2 per year

15. Evaluating building data
One of the most important topics to evaluate is thermal conductivity. The energy efficiency of a building is affected by the thermal conductivity ‘k’ (measured in Watt per square metre Kelvin (W/m2K)) of the materials used. This value differs between materials and can be obtained from suppliers. The lower the k value the better the material at preventing heat loss. Material thickness also influences efficiency. In measuring the overall efficiency of the fabric of a building it is necessary to take into account all the materials used (inter wall, insulation, air cavity and outer wall). The thermal transmittance ‘U’ is a measure of the rate of flow of heat through a building element (e.g. a wall, or roof).

16. Evaluating building data
To analyse the quality of the building construction it is helpful to obtain the following information:
Year of construction
Building materials
Insulation materials
Types of doors and windows

17. Insulation materials for buildings
When choosing insulation material the following selection criteria must be taken into account
Thermal quality of insulation material Different materials have different thermal conductivity. Select the one with the lowest thermal conductivity figure.
Thickness will be chosen according to national standards and requirements
Flammability There are national standards on what type of materials are allowed to be used in various locations. The materials themselves are categorised into classes of flammability
Humidity Consideration should be given to the resistance of the material against water vapour and to its absorbability

18. Characteristics of thermal insulation materials
The picture shows the most popular insulation materials.
Mineral wool with aluminium vapour restraint
Mineral wool in slice form. Material appropriate for loft insulation
Mineral wool felt
Foam polystyrene sheet
Wood-fibrous sheet. Used as thermal and also acoustic insulation
Wood-fibrous sheet with tongue and slot
Plaster-fibrous sheet for indoor insulation of building envelope
Cork insulation sheet without adhesives and additives

19. Characteristics of thermal insulation materials
Some characteristics of thermal insulation materials are given in the following table.

20. Where to insulate The following aspects should be looked at: openings
roofs
outdoor walls
inside
floors

21. 1.Where to insulate - openings
The weakest parts of the building are doors and transparent constructions. Windows can be a source of heat loss as well as passive solar gains. Windows represent a considerable share of the total building thermal losses (30 to 50 %).

22. Where to insulate - openings
Thermal losses through windows are through heat transfer and ventilation. Thermal losses through both the glass and the window frame are to be taken into account. Frames are generally made of wood, plastic, metal or a combination of these materials. Wooden window frames give the best thermal insulation characteristics.
Thermal-technical properties of windows depend on
air gap thickness - optimal is thickness of about mm.
type – single, double and triple glazed
filling – air or inert gases.

23. Where to insulate - openings
Replacing the windows with energy efficient ones also has the advantage of better indoor conditions (e.g. improved sound insulation, less draughts). Payback period is normally around 15 years. One of the most cost effective activities is to exclude draughts from gaps around doors and windows. This is also easily done with the use of draught excluder strips. However, the tightness of windows must not be too high as it has to allow for some minimal air exchange. Secondary double glazing is another option for thermal insulation of glazed surfaces. The additional glass can be installed on the inner or outer side.

24. 2.Where to insulate - roofs
Losses through uninsulated roofs account for 8-15% of the total energy consumption. With proper insulation of the roof, savings of about 5 – 9% are achievable. Roofs are insulated on the inner side. Selection of type of insulation is governed by the roof construction, thermal requirements and flammability.

25. 2.Where to insulate - roofs
FLAT ROOFS Mineral fibre panels with a specific weight of not more than 100 to 150 kg/m3 and which are not compressible by more than 10 % of their initial thickness should be used. To prevent thermal conductivity by presence of water vapour in the insulation a vapour barrier layer should also be installed.

26. 2.Where to insulate - roofs
SLOPING ROOFS.
Consideration should be given to whether the roof space will be inhabited or not.
If the roof space will not be inhabited it is recommended to insulate the external surface of the last ceiling. If the ceiling construction is made of timber then the most appropriate thermal insulation is glass or mineral fibre. Thermal insulation could be installed in two layers. However, such thermal insulation is not appropriate in spaces with high moisture content.
If inhabited and heated the roof construction itself should be insulated. As timber is often used in constructions of sloping roofs it is recommended to use thermal insulation materials which are non flammable, such as mineral fibre materials.
It is important to
use a vapour barrier
leave an air gap between the insulation and the roof tiles.

27. 3.Where to insulate - outdoor walls
Losses through uninsulated outdoor walls account for 20-40% of the total energy consumption. With proper insulation of the walls more than half of the energy loss can be saved. Outdoor walls can be insulated from inside or from outside.

28. 4.Where to insulate – inside

29. 4.Where to insulate – inside
Outside insulation. Outer insulation is, from the technical point of view, a better solution for additional insulation.
Thermal installation using laminated foam material or mineral wool - or if the outer side of the wall has to be rendered or finished in brick - will be much more expensive than inner insulation.

30. 5.Where to insulate - floors
Thermal insulation layers are usually made of foam plastics or fibrous insulation: polystyrene sheets - sheets from laminated polystyrene and polyurethane. The thermal insulation layer is mostly covered with hydro-insulation foil. Typical thickness of insulation is 20 to 60 mm. The bulk density should reach 20 kg/m3 and compressibility should not exceed 5 mm. Thermal insulation used for insulation underfloor heating should be from laminated thermal insulating foam. Most effective are sheets from foam polystyrene or laminated polyurethane. Buildings without cellars have to be insulated against ground moisture

31. EXAMPLE – Energy savings
Example of energy savings (calculated for heating system energy consumption), which can be obtained by additional thermal insulation of an industrial building with an annual energy consumption kWh.

32. B. Reasons for building services insulation
The second area where insulation is to be considered as important is for building services.
The main reasons for the insulation of building services are:
to reduce losses
to control process temperature
to provide frost protection
to protect pipes, equipment and construction from mechanical damage

33. B. Reasons for building services insulation
The main reasons for the insulation of building services are:
to reduce losses. Distribution pipe-work in buildings carry heating and cooling fluids. Such systems could be central heating, hot and cold Water, ventilation or production processes. To reduce losses and thereby increase efficiency of energy systems it is necessary to insulate pipes and service devices.
to control process temperature
to provide frost protection
to protect pipes, equipment and construction from mechanical damage

34. B. Reasons for building services insulation
The main reasons for the insulation of building services are:
to control process temperature. Insulation should avoid heat or cold losses into the environment and maintain the temperature of the medium in pipes, distribution network or building services equipment. Heat transfer losses result in a higher demand on the sources which means additional loading resulting in higher energy consumption.
to provide frost protection
to protect pipes, equipment and construction from mechanical damage

35. B. Reasons for building services insulation
The main reasons for the insulation of building services are:
to reduce losses
to control process temperature
to provide frost protection. Operation of systems under certain temperatures could result in higher energy losses and damage to pipes and devices due to frost. Special attention should to be paid to cooling installations to prevent water from condensing on the external surface.
to protect pipes, equipment and construction from mechanical damage

36. B. Reasons for building services insulation
The main reasons for the insulation of building services are:
to reduce losses
to control process temperature
to provide frost protection
to protect pipes, equipment and construction from mechanical damage. An additional benefit of thermal insulation is also the protection of pipes and equipment against accidental mechanical damage

37. Disadvantages of low efficiency distribution
Poorly insulated or low efficiency distribution systems can result in:
Cooling systems frequently switching compressors on and off, leading to their early replacement.
Heating systems giving insufficient temperature of heating panels and radiators and lower efficiency boiler operation.
Air-conditioning systems unable to provide the required amount of supplied air.

38. Analysing the current state of insulation
Inadequate thermal insulation of pipes and devices can often be identified by walking around the building to
visually inspect pipes
simply touch pipes to get an idea of their temperature.

39. Analysing the current state of insulation
All heat carrying pipes should be insulated, especially if passing through spaces with different indoor conditions. Examples of these are cellars and storage halls.
If the surface temperature of space heating pipes is hotter to the touch than ambient this shows that the thickness of thermal insulation or its quality is not sufficient.
If the surface of cold water pipes or coolant pipes shows signs of condensation, then this is an indicator of insufficient insulation. In some conditions such condensation could freeze and thus damage pipes or devices

40. Analysing the current state of insulation
Visual inspection. If there is no information available about the current status and quality of building services insulation it will be helpful to inspect the pipes in a systematic way.
The following points has to be considered:
Condensation
Mildew
Corrosion of pipes
If any of the above are apparent it could be due to
inadequate insulation
leaking pipe connections
defects in pipes

41. EXAMPLE – Isolation on pipes
The following pictures show good and bad insulated distribution pipes
Well insulated distribution pipes, non insulated valves
Advanced corrosion of pipes as a result of insufficiently insulated pipes
Damaged insulation on distribution pipes

42. Thermo images
Having completed the visual inspection and taken corrective actions the next step would be to use a thermo camera to produce thermo images.
Thermo images show areas of losses which are otherwise not easily visible. Images should be taken of boilers, ventilation and distribution pipes, tanks etc. Images showing differences in temperatures of a pipe could be an indication of the undesirable cooling/heating of it as it passes through different areas.

43. EXAMPLE – Thermo images
Thermo camera photo taken of an uninsulated distribution pipe

44. Measurements
Measurements are rarely performed for evaluating effectiveness of insulation of pipes boilers etc.
Measurements and detailed analysis will normally be undertaken by specialists.

45. Insulation materials for building services
Thermal insulation of building services should consist of
thermal insulating layer and
surface treatment.
Thermal insulation should be used on all parts of building service equipment and on all types of pipe work.
Surface treatment can be either wet (e.g. mortar, protective paint ) or dry (sheet, foil, cardboard). It also provides a coat which protects the equipment and pipe work against other influences.

46. Insulation materials for building services
Insulation materials are available in many forms: preformed, flexible, loosefill, plastic composition, spray-applied, foamed in situ, micro- porous insulation, reflective insulation, insulating boards, bricks and allied products, insulating concretes, prefabricated shapes The following table is also available as a doc-file.

47. EXAMPLE – pipe insulation
Rock mineral wool – thermal and acoustic insulation for pipe distribution network, district heating, flu gases pipeline system. Rock mineral wool with surface treatment – aluminium foil (mechanical and pressure resistant).

48. EXAMPLE – Thermo images
Rock mineral plates (fireproof, pressure and water resistant), used for ventilation pipeline system insulation. Combination of different insulation materials: elastomer (black rubber) without surface treatment used for insulation of distributors and closing valves (maximum short-term temperature 120 to 125 0C) and polyethylene insulation on distribution pipes with temperature 900C.

49. Define subsystem boundaries
Selection of the insulation material for building services and building equipment has to take the following into consideration:
Purpose (to prevent heat losses, condensation control, insulation of cooling pipes)
Operational temperatures of processing liquid (see table)
Temperature and air humidity of surrounding environment
Thermal-physical parameters of material
Lifetime and resistance of material
Health and safety requirements
Operating conditions, which very often change, must be considered when planning or implementing thermal insulation. In certain instances it is necessary to consider not the average but the maximum (extreme) operating condition.