Bruce - thanks for the Article. I was born and raised in Worms, Germany; about 40 Km from Darmstadt and am quite aware of this structure. Have also been following your comments in Re: Crawl space started by Manfred and think that we all should have a conversation. Might be able to add some insight!

Mfg (With friendly Greetings)
Heinz B. Horn
Isomax of Mo.
IsomaxHH@aol.com

This article caused me to revisit the Passivhaus website http://www.passiv.de/ which I had not visited in a couple of years.  The latest version of their planning software now includes active cooling and non-residential buildings, so I think I will invest in it for educational purposes.

My future home project will near the Gulf Coast (on solid limestone) so I am more interested in cooling than heating on a personal level, but since I work in the commercial building industry it is also interesting from a professional point of view. 

I am in Milan but drive to Mannheim twice a year to visit a large vintage motorcyle/auto fair and know that Darmstadt is not far away.  My German colleagues built Uptown München (Munich) and Main Tower in Frankfurt.  Both are high rise office buildings with operable windows and chilled beams/ceilings for cooling.  My projects in Milan will use open loop (non-potable) groundwater and heatpumps for heating/cooling and we are LEED (C&S) precertified silver.

Ciao,

Bruce

indeed an interesting article. It sounds much like something I have been trying to get across on another forum. They don't go into much detail though on how they achieve the same temoperature in the wall as it is required in the room.

It seems the basic tenets are superinsulated w/ heat exchanger?

The basic requirements taken from http://www.passiv.de/English/PassiveH.HTM 

Compact form and good insulation:	All components of the exterior shell of the house are insulated to achieve a U-factor that does not exceed 0.15 W/(m²K) (0.026 Btu/h/ft²/°F).
Southern orientation and shade considerations:	Passive use of solar energy is a significant factor in passive house design.
Energy-efficient window glazing and frames:	Windows (glazing and frames, combined) should have U-factors not exceeding 0.80 W/(m²K) (0.14 Btu/h/ft²/°F), with solar heat-gain coefficients around 50%.
Building envelope air-tightness:	Air leakage through unsealed joints must be less than 0.6 times the house volume per hour.
Passive preheating of fresh air:	Fresh air may be brought into the house through underground ducts that exchange heat with the soil. This preheats fresh air to a temperature above 5°C (41°F), even on cold winter days.
Highly efficient heat recovery from exhaust air using an air-to-air heat exchanger:	Most of the perceptible heat in the exhaust air is transferred to the incoming fresh air (heat recovery rate over 80%).
Hot water supply using regenerative energy sources:	Solar collectors or heat pumps provide energy for hot water.
Energy-saving household appliances:	Low energy refrigerators, stoves, freezers, lamps, washers, dryers, etc. are indispensable in a passive house.

Logic and common sense, noting that this is for a heating dominated climate.

What's interesting is that they put a 'Does Not Exceed' instead of a Minimum on the shell insulation factor. 0.026 BTU/Hr or R-38.46. And, that is about what I've always considered Super Insulating.

Those of you who find the idea of a "Passive House" interesting may enjoy this link:
http://www.dennisrhollowayarchitect.com/html/Champion1.html

It shows a home in Colorado and has very specific details on how it was constructed and answers a lot of questions I had.

Cheers