Opening the green door
Ever since the first cave man came up with the idea of shielding the family dwelling by hanging a fur rug in front of the cave’s opening, doors have been instrumental to the comfort and security of a home. Today, door manufacturers (and individuals) have to conserve resources and consider environmental sustainability unless we are to return to the Stone Age.
From architects and builders to home owners, there is a lot that can be done when it comes to improving energy efficiency in doors and windows. In Britain, for example, the Energy Saving Trust says that installing eco-friendly doors and windows may cut energy bills by up to 20 percent.
But getting new equipment isn’t the only path towards a greener planet. Home owners can contribute a great deal to energy conservation (and lower utility bills) simply by being more aware of how much they are actually using up. This used to be quite difficult to assess, but the task has become a lot easier by the development of new intelligent home monitoring systems from companies like Manodo, whose new SBox – developed in cooperation with ASSA ABLOY – offers access control as well as energy consumption readings. Once you see how much you use, it’s easier to cut back.
Door manufacturers are doing their part in the sustainability efforts too, by designing doors that contribute to energy conservation. US company Curries, for example, has added an insulating gasket option to their door frames to help protect against heat loss. Christened the CURRIseal, it makes for an energy-efficient thermal break frame that prevents heat from leaving the building (or cool air, if the climate requires air-conditioned comfort).
Curries strives to use recycled content and other environmentally friendly materials in the construction of its doors and frames, says Marketing Manager Dave Goetzinger. “Steel is one of the most recycled products in the United States and the steel that we use has a minimum 27 percent recycled content in it. That helps towards meeting the US Green Building Council LEED criteria for recycled content.” (See related article)
Graham, another US door manufacturer that specializes in wooden doors, is also continuously looking for more ways to use renewable and recycled materials. One example is substituting freshly axed timber with agrifiber, which is made from the wheat and straw shafts that are left standing after farmers have harvested. Previously plowed back into the ground as waste products, this new material provides more LEED points, specifically for the use of rapidly renewable materials (Wood is of course also renewable, albeit not at the same speed).
Another means for wood door manufacturers like Graham to assist buildings to secure more LEED points is to avoid using potentially health-jeopardizing chemicals like urea-formaldehyde (which used to be common in laminated wood products such as plywood) that give off emissions.
“In the aftermath of hurricane Katrina, some residents suffered breathing problems for a long time, since the trailers provided as temporary housing were constructed with plywood with high levels of urea-formaldehyde,” Goetzinger points out.
Finally, some doors do more than conserve energy. Dutch company Boon Edam for example, has developed a revolving door which actually generates new energy every time someone passes through. The concept, which has been installed at the Driebergen-Zeist railway station in The Netherlands, is equipped with a generator that is powered by the human energy applied to the door, while also controlling the rotating speed of the door.
The ceiling of the revolving door is made of safety glass and gives a clear view of the technology. A set of super capacitors stores the generated energy and provides a consistent supply for the low energy LED lights in the ceiling. If these lights have used up all the stored energy, the control unit switches to the alternative mains supply of the building. This ensures that the door is illuminated at all times, even when the passenger flow is minimal.
LED scales inside the door indicate the amount of energy that is being generated. When passing through the door at a slow speed, the scale will end up in the red or orange zone, whereas a normal or fast pace pushes the scale into the green zone, indicating that significant electric energy is generated. ‘
Another LED indicator at the control unit shows when the illumination of the revolving door is powered by human energy, or by the mains supply. ‘Human Powered Energy’ stickers were applied to the revolving door to make users aware of their contribution to the green building. The total amount of accumulated energy that is generated by these revolving doors is shown on a large display.
Extra energy points for stressed commuters, no doubt.