Why a zero-energy-house is not economical in terms of energy needs, and what would be more efficient and economical
My partner wants us to build a new house. I'm against a new building – that is, unless it costs less to heat and cool than an old building. Do you think you can help us figure out how to design such a house?
The problem with current low-energy houses
Europe, and Germany in particular, is quite hot on energy-saving construction techniques. But I'm a hands-on homeowner and I'm no fan of these new passive house designs – in my experience, insulating actually drives up the energy costs. Want to know why?
1) The demand for fresh air. Zero-energy houses are designed to be air-tight. And we people have a strong desire for fresh air – so strong, that we open the windows every day to trade the stale air indoors for fresh air from outside. And we're not as "bad" as other families, which leave the window constantly open in winter! Result: the actual effectiveness of good insulation is severely reduced by our leaving-the-window-open strategy of getting fresh air.
2) The prolonged heating season. Thanks to the good insulation, the house stays cool longer than it had before the insulation. That means, I now have to heat the house into June.
To be very honest: I have not noticed any savings in terms of the amount of fuel that I need per year.
A more economical approach to the passive house problem
Did you ever wonder how the traditional Eskimos managed to keep their igloos above freezing, despite the walls of ice, the frigid temperatures outside, and an open door and ventilation hole? Or did you ever wonder how the ancient Persians managed to keep their lofty desert mansions cool, despite the scorching heat and freely circulating airflow? If we took that as a starting point… then the energy requirements for a modern house could be lower than what we have today, especially for an average family who wants a lot of fresh air.
Yes… environmentally friendly systems for heat exchange and heat retention! So, let me start with two questions:
(1) Are you aware of any other traditional temperature control mechanisms, such as the sunken igloo entrance and wind towers alluded to above?
(2) How could we adapt those solutions to outfit a modern passive house, and yet keep the open air circulation concept instead of focusing solely on insulation?