WINDOWS THAT ARE GOOD FOR THE ENVIRONMENT AND YOUR POCKET
Builders and architects are being challenged today to design and build eco friendly, energy rated homes. A Building Energy Rating (BER) certificate rates the energy performance of a building on a scale similar to that for electrical appliances. Band A is the best and band G is the worst.
The challenge was taken up by Fingal County Councils design team to create an A rated home on its housing development near Oldtown, Co. Dublin. The initial brief was to achieve an A3 rating but this was upgraded to an A2 by the end of the project. Key aspects of design were insulation, glazing, solar gain, heating systems, ventilation, lighting and appliances. The house, which featured on last Tuesday’s About the House on RTE, is built with sustainable materials and showcases energy efficient products from Irish companies.
Fingal County Council chose Munster Joinery’s PassiV Hardwood window for this high spec project.
Blower Door testing was used to establish the airtightness rating of the building - 0.7 air changes per hour at a pressure of 50Pascals. Under the 2008 Building Regulations a dwelling must achieve less than 10 air changes per hour. This house was fourteen times better than the requirement!
Fingal County Council have achieved a first for a public authority in Ireland - a social and affordable home whose energy efficiency, airtightness and fresh air quality far exceed the requirements of current building regulations. This has been achieved at little extra cost and is indicative of the energy saving standards that will be applied all Irish homes in the future. The lucky future residents can expect to pay a heating bill of €150 a year.
A key component of any energy efficient home is the windows but there’s no need to be blinded by science when choosing windows. We are on the case, manufacturing the best performing windows to achieve excellent BER’s. You might think that one double glazed window is the same as another but not so; there’s an art and a science to good windows, and today we may be talking triple and quadruple glazing
The EcoPassive window is a Tilt & Turn timber window designed to give the thermal performance and airtightness to achieve an A rating. The window is 110mm deep and offers both triple glazed and quadruple glazed options. The glazing includes low-emissive glass layers which have a coating that reflects heat back into the room. Warm edge spacer bar technology reduces heat loss around the edges. An exceptionally clear low iron glass is used to maximise the heat gained from the sun. The glazing unit is filled with either Argon or Krypton. These are inert gasses which have a lower conductivity than air meaning even lower heat loss.
This is the most energy saving glazing available and all these features give the window a really low U-value. This is a measure of the heat loss per unit area of window per degree temperature difference between inside and outside. Low U-values are essential to achieving an energy efficient home, a reduced carbon footprint and an excellent BER for your building. The EcoPassive window can cut heat losses by up to 80% on a conventional double glazed window.
The window has an efficient seal system which eliminates unwanted air leakage. Uncontrolled air loss from a building can account for as much as 30% of building heat loss. This has a significant impact on comfort , heating costs and maintenance.