Archive for October 22, 2008

What is the ‘Next Generation’ home?

Looking at the current old stock and all the newly built houses here in the US, it seems to me that conventional stick built homes just do not cut it anymore in terms of thermal performance, durability or quality.

So, what is the alternative?
While searching for an example of ‘next generation home’, I looked over the pond to see how Europeans build homes. What I saw impressed me greatly. It looks like they are well on their way of building smartly, with energy efficiency in mind using sophisticated materials and technologies. To find out how they do it, go to www.creategreenhome.com/Build_Green_Home.htm.

Thermal performance and energy use values of their homes are impressive. The trick is in the tight, and smartly insulated building envelopes. What is driving all this in Germany are the regulations at the federal level for the thermal efficiency and energy use values for all new houses. Following htese guidelines and regulations, houses are built today in Germany that consume as little as 500 Euros (~$650) of energy per year for heating and cooling!
Even so, they just recently (in 2007) increased the building thermal efficiency requirements by another 30%! That is a huge new challenge to the building industry, but it will inevitably lead to impressive technological solutions from which we can all reap the benefits.
As an comparable methodology her einthe US I would perhaps mention the Modern Prefab homes. They are gaining in popularity and offer a lot in terms of improving the quality and thermal efficiency of building envelopes by using technologies like SIPs or AACs. Their designs take advantage of architectural features that enhance natural cooling, for example by strategically placing windows and incorporating some new technologies for heating and lighting. They are on the right track and worth exploring.

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Solar Hot Water System drastically reduces use of Natural Gas

While building a new home in northern Italy, a young family did not think twice about using energy efficient features to reduce their dependence on the expensive energy sources.

First of all, the house has a well insulated building envelope, where external walls (45cm thick) and the roof have multiple layers of insulation (placed on the cold/outer side of the wall). The windows also are multipane with energy emmisivity characteristics to reduce energy loss trough the glass and frames.

The most interesting feature of their energy efficient home is the Solar Hot Water system. It consists of two small collector panels, (total area of 2.8 m2, or ~9 ft2), set of connecting pipes, hot water tank (300 lit, ~80 gal) along with solar pumping station and expansion tanks. The system is filled with a refrigerant (antifreeze, antiboil) that exchanges the energy with the water in the tank through a built in coil heat-exchanger.
Solar panels are built in to the roof structure, set flush with the tiles providing minimal interference with any other structure on the roof while receiving good accessibility for service. The SHW system is manufactured by Sonnenkraft, a company from neighboring Austria. Total installed cost in 2005 was €5000 (about $6000 at 2005 exchange rate). The system supplies ample hot water for ALL hot water needs during months of May to October when the family switches off their gas burner completely.

Solar Hot Water Panels, Solar hot water system components

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