The cheapest, cleanest, and most abundant energy resource is energy efficiency. It is a very simple concept—using less energy to get the same amount of heat for our homes, same amount of light for our offices, and same amount of power for our cars. It is really about getting the same or more with less.
There are two general categories of energy efficiency measures:
· First, using more efficient machines and designs such as the compact fluorescent bulb that usually resemble high end onion rings;
· Second, improving the efficiency of existing machines and structures, such as insulating our homes.
As buildings use nearly two thirds of our power they ought to be the prime target for implementing energy efficiency measures. In recent weeks more attention is being paid to the Passive House rather than on the crumbling housing market. (Elizabeth Rosenthal, New York Times, December 27.2008) The Passive House involves a design and construction standard that reduces the heating requirements to such an extent that conventional heating systems are no longer required in the building. The term passive comes from the fact that the home maintains a steady temperature and does not depend on fossil fuel generated heating.
There are no drafts, no cold floors, no waiting for the heat to come on in the Passive House. In fact there are no furnaces in such a house. They are well insulated and air tight and are heated by the free heat generated from appliances such as refrigerators, ovens, lighting, and computers operating in the house. Of course body heat and external solar heating of the house are also captured in such a system. It is important to note that these structures do have windows that can be opened and most of them face south than north. The Passive House is an excellent idea—why not uses the heat that one can obtain free?
What about ventilation in such an airtight capsule? Previous attempts at building solar heated homes failed because of stagnant air and resulting mold. No problem. The new design has a smart mechanical ventilation system that brings in fresh air while eliminating the same amount of stale air from the house. What is really impressive is that the stale air carrying the free heat transfers the heat to the incoming fresh air prior to its leaving the building. Such a system enhances the air quality of the house greatly. An added feature of the design is that the house has zero emissions. (Pat Murphy, http://www.energybulletin.net)
The concept of the Passive House originated from the city of Darmstadt near Frankfurt in Germany.( Passivhaus Institut )The first Passive House was built by Wolfgang Feist, a physicist from Darmstadt in 1991.Such homes are becoming increasingly popular in Germany and Scandinavia. Today they require 85% less energy than a house built to existing German building standards. (Hans De Keulneur, Intelligent Energy for Europe SAVE program) What is impressive is that the additional construction cost in Germany is only 5 to 7% more than the standard house costs.
The Passive House industry is growing fast in Germany. Schools in Frankfurt are built with the latest Passive House technology. The European Parliament is now proposing that all new buildings meet these standards by 2011.Now even the U.S army in Germany is considering building their barracks with this technology. Currently there are nearly 15,000 Passive Houses in existence around the world. Vast majority of them are in Germany.
The movement is slowly gaining momentum in the U. S. Recently the Passive House Institute US held its third annual conference in Duluth, Minnesota. By contrast, the European Institute recently held its 12th conference in Germany. So far we are mostly talking about the concept rather than embracing it as they have done in Germany.
Nabih Tahan, a California architect, who worked in Austria for more than a decade, recently retrofitted his older home in Berkeley to Passive House standards. It is now a demonstration Green Home in the Bay Area. ( Hopefully the Passive House movement will gain a foothold in the Bay Area and spill over to the other regions of the U.S.
Undoubtedly the Passive House concept extending to all buildings could play a crucial role in cutting our national energy consumption. This would not only enhance our building practices but lead our nation to energy independence as well providing us with a major strategy for meeting the challenges of climate change and environmental pollution. Energy efficient buildings are a big deal.