Even when houses are well insulated, up to 40% of energy is lost due to leaks in the building’s external envelope. Cold air penetrates through joints and seams in the form of draughts, forcing your heating system to struggle to maintain a constant level of warmth. As a result, the average house built in Ireland and the United Kingdom – due to excess air infiltration and ex filtration – ends up having to heat 4–5 times more air than is actually needed in order to maintain a comfortable temperature. A well-installed airtight layer reduces these unwanted draughts and air loss, thus reducing the amount of air you need to heat, which in turn saves energy and produces an environment which can be controlled not only in terms of temperature, but also in regards to ventilation and humidity.
DRAFTS ARE NOT ALLOWED IN
Drafts through every little nook and cranny can have an adverse effect on the comfort of a room. The cold air that is drawn in at leaky or un-tight joints and penetrations is heavier, and moves to the lowest point in the room, that is, the floor. The result is cold feet – an unpleasant sensation of drafts, difficulty in maintaining consistent heat within the room and increased energy usage. Not even a good level of insulation can maintain a comfortable indoor environment if air from outside enters through these natural, hard-to-see joints between the building elements.
IMPROVED THERMAL PERFORMANCE
Gaps in outer construction elements have a considerable negative influence on the insulation. An example: if a construction component measuring 1 x 1 metre and 14cm thick has a continuous gap of only one millimetre, the U-value deteriorates from 0.3 to 1.44 W/m2K. This is due to the fact that warm or cold air is escaping through leaks in the building’s envelope, and as it passes through the structure and insulation, it reduces the thermal performance by extracting the stored energy within. An airtight external envelope does not only provide protection against cold in winter but also against heat in summer.
PROTECTION FROM CONDENSATION
Another aspect of air filtration/ex filtration is the build-up of condensation within the construction element or as in most cases within the insulation that it haspassed through, as the air leaves behind the humidity that it carries, this results initially in a deterioration of the U-value (the ability of the insulation to retain hot or cold.) A far greater problem is that this leads to serious damage in the construction if the moisture cannot dry out quickly. It is estimated that two thirds of all damage caused by damp in the building sector is as a result and explained by lack of air-tightness.
Variable Moisture dries back out towards the interior of the structure during the drying out months, this type of variable/intelligent membrane is ideally suited for flat roofs which are non vapour diffusive towards the outside.(Calculations should be carried out in order to ensure the suitability of such membranes) Fixed sd such as our Timbertex airtight vapour control membranes are suitable for almost all applications involving make-ups which are diffusion-open to the outside, keep in mind the internal sd value needs to at least 6 times higher then the external sd value. Vapour blocks are suitable for make-ups that are open to diffusion on the outside, total vapour blocks are generally used in environments with high moisture content such as commercial kitchens.
IMPROVED QUALITY OF AIR
Leaky areas in the internal walls and around penetrations such as pipes, windows and building components are not advantageous to the atmosphere in a room, as dust and fibres from insulation can escape into the internal air. Walls sealed with Isocell products ensure indoor air quality, when properly ventilated, or when functioning air conditioning/heat ventilation recovery systems are used.
NOISE STAYS OUT
Noise finds its way through even the smallest of cracks. Even if the elements surrounding the room have good acoustic insulation, gaps can considerably increase the noise level. With Isocell Airtight Systems you can also solve this problem and keep annoying noises out.
MECHANICAL VENTILATION WORKS PROPERLY
If you have a mechanical air conditioning or ventilation system, your building must be particularly airtight as otherwise the mechanical system will not function properly, and will actually draw in cold or warm air from the outside in a uncontrolled manner, making it very difficult for the system to regulate the internal temperature, thus forcing the system to run at a higher rate in order to compensate for the variances.The maximum permissible value for air permeability, according to ISO-Norm 9972, is three times as high as for buildings without mechanical ventilation systems, for buildings with mechanical ventilation an air tightness of 1.5 ACH@50PA is recommended in order for the system to operate efficiently, reducing this down to 0.6ACH@50PA or “Passive Standard” in conjunction with cold bridge elimination and proper levels of insulation and triple glazed passive certified can help to truly maximise the energy efficiency of your home.
The Airtight test
At Isocell we believe that the most important element of any structure is the external shell. Only by building this right can you truly achieve an energy efficient, comfortable and durable structure. What’s the point in bolting on renewable’s when the structure is not designed to maximise their benefits. Pound for pound you will get a better return for your money by ensuring proper insulation, air-tightness, and the elimination of cold-bridging. By building right and building tight you can offer your clients a better built home, and take advantage of the benefits that air-tightness brings in regards to BER and SAP energy ratings .
Isocell allows you to build right and build tight by providing a range of products specifically designed to achieve the desired result. Using alternative solutions that are not designed for the purpose of air-tightness can lead to problems in the short to medium term as they lose their effectiveness and sealing properties due to settlement and movement within the building and elements. Isocell products are designed and manufactured to cater for this, providing a guaranteed system that will stand the test of time.
Create a pleasant atmosphere in the rooms and save money at the same time – with ISOCELL’s airtight systems the advantages are obvious:
Improved thermal insulation
Protection against defrost water in the construction
Improved air quality
Your ventilation system will work perfectly
Noise stays outside