Air Tightness Testing
Air Tightness Testing identifies areas of the building that are experiencing heat loss through gaps and cracks in the envelope of the building fabric. The only satisfactory way to show that the building fabric is reasonably airtight is to measure the leakiness of the building fabric as a whole. It has been estimated that approximately one third of building energy losses may be attributed to uncontrolled ventilation & air infiltration. In building energy calculations this has traditionally been estimated by building services engineers without any form of direct measurement being applied. By the use of building air pressurisation / depressurisation testing it is possible to quantify the air leakage rate from a building and to also assess exactly where this leakage may be taking place.
Thermal Image Inspection
Thermal image inspection (thermography) can be defined as the detection and measurement of emitted thermal energy (heat). This is enabled by the use of an infrared camera which translates the invisible infrared spectrum into a visual format, or thermal image. This thermal image can then be interpreted to provide a non-invasive and non-destructive method of identifying building defects and deficiencies.
Thermal imaging uses infrared technology to detect very small differences in temperature. Every material has a unique thermal signature. When moisture heat, or cold are introduced into the structure the thermal signature changes. With the help of this incredible camera we can see many things that simply are not detectable to the naked eye.
Cold areas behind walls, floors, or ceilings can indicate the presence of moisture, or lack of insulation and the infrared camera helps us diagnose these problems easily. Thermal imaging also easily detects overheating circuits, fuses, or circuit breakers. In some cases, flat roof leaks, or leakage under, or behind plumbing fixtures can also be found.
There are two primary mechanisms for heat loss in buildings:
- Conductive losses
- Air Leakage.
Both can be identified from the surface of the buildings with infrared thermography.
Problems identified as conductive losses are: missing insulation, improperly installed or compressed insulation, shrinkage or settling of various insulating materials, excessive thermal bridging in joints between walls and the top and bottom plates, moisture damage to insulation and building materials, heat loss through multi-pane windows with broken seals, leak in water pipes, etc.
Air leakage is the passage of air through a building envelope, wall, window, doors etc. Leakage to the interior is referred to as infiltration and leakage to the exterior is referred to as exfiltration. Excessive air movement significantly reduces the thermal integrity and the performance of the envelope. Therefore this is a major contributor to the energy consumption in the building.
Below are two sample images of the same area ( visual on left and thermal on right). Nothing is apparent when looking at the visual image but missing insulation is very apparent in the thermal image. Lighter colours represent progressively warmer temperatures (areas of missing insulation), while darker colours represent progressively cooler temperatures.
Building Energy Rating (BER)
Under the Energy Performance Building Directive (EPBD), a Building Energy Rating (BER) Certificate is required with effect from the following dates:
- 1st January 2007 - New dwellings applying for planning permission.
- 1st July 2008 - New non-domestic buildings offered for sale or rent.
- 1st January 2009 - Any existing building/dwelling offered for sale or rent.
A BER Certificate indicates the energy rating of a property on a scale of A (most efficient) to G (least efficient).
A provisional BER rating is required if you are selling a property from plans. The provisional BER Certificate which is valid for two years from the date of issue, must be provided to the potential buyer of the property. This rating is based on pre-construction plans and specifications.
A Full BER Certificate must be provided to the buyer on completion of construction of the property. The Full BER Certificate takes account of any changes implemented during construction related to plans, specifications or other data through which the provisional BER was calculated. This certificate is valid for 10 years from the date of issue.
How is a BER calculated?
We offer a further service for those who do not need a BER Certificate but wish to improve the energy efficiency of their home or those who are unhappy with the current rating. An Energy Audit will involve in-depth investigation of all elements of the dwelling, which affect the energy performance of the building, e.g. windows and doors, wall and roof insulation, water and space heating system(s), ventilation and lighting.
We will provide extensive recommendations on improving on the current energy rating and achieving the target energy rating taking into consideration the budget and all the circumstances.
As part of our energy audit service we can carry out Air Pressure Tests and Thermal Imaging which will show the areas of the building where the heat escapes. Having studied the building in detail, a schedule of potential energy saving solutions is compiled. Each solution is then analysed in detail to determine it's suitability for the particular application.