Latest projects & news
- Wolf partner with Genersys Solar
- Passive House in Newbridge (video on Homepage)
- Vphase: Sunday Times & featured on DIY:SOS
- Energy efficiency ratings to be compulsory for home sales
- CNN meets Hans Eek & reports on PassivHaus retrofits
- Hans Eek - The Vision & the Visionary of the Passive House Concept
Airtightness & Upgrading an Existing Building
By upgrading the building envelope with insulation, the heating consumption can be reduced, and thereby if the existing heating system is kept, it can run at a lower temperature. Or, in turn, this also allows for more energy efficient systems to be used, such as condensing boilers and heat pumps.
Research shows that problems caused by thermal bridging actually decrease when exterior insulation is increased, and generally reduce the problems with moisture or damp. The increased insulation will also compensate for the high heat losses of old buildings, through the exterior walls.
It’s advisable to aim for a high level of air-tightness to avoid uncontrolled air leakage, as there is always a risk of condensation through moisture in the air. Remember that the windows can be a significant weakness to airtightness. Triple glazed windows with an efficient U-value will enhance the airtightness of the building shell.
Whether designing a new building or upgrading a property, the planning principles remain the same. In upgrades that have already been completed, the air-tightness proved to be surprisingly good. In this context, Dr Feist, the founder of the Passivhaus Institute in Germany, also pointed out the importance of controlled ventilation, Those who call for airtightness, also need to achieve adequate ventilation.
With any airtight building, thought must be given to the method of removing stale air and introducing fresh air. This is easily achieved with mechanical ventilation and becomes more crucial when modernizing old buildings.
• Air must be constantly renewed
• The most important task is the dehumidification of kitchen, bathrooms and toilets by extracting the damp air
• The air exchange rates need to be calculated correctly to avoid the air becoming too dry
Research has also shown, that the heating requirement of the demonstration projects in Ludwigshafen and Nuremberg have been reduced to less than 30 kWh/(m²a). This means the energy-efficiency of the existing buildings has increased and is 8 times better than before the upgrade. The documented measurements from the demonstration projects show that the actual results are even better than the calculated theoretical values.
• provide greater protection against moisture damage
• improve the thermal comfort due to higher surface temperatures
• raise the potential for energy-conservation drastically
High-quality modernization is more easily achieved with the use of highly efficient components and the quality of life for residents increases significantly. Modernization measures in buildings are a key driver for the economy. The measures outlined show a 75% reduction of CO2 generated in the case studies. Energy efficiency improvements are in a sector in which a reduced consumption, also allows for increase in the appropriate use of renewable energy sources.