Glass walls and HVAC

singh

Interesting read.

Can this be the end of duct work?

http://www.architectureweek.com/2005/0420/building_2-1.html

Constantin

Intersting indeed...

... I have to be honest and admit that I was a bit skeptical when I saw the tower in Bonn. This technology seems quite suited for structures which are not very deep... as the natural convection benefits those that are closest to the outlets the most. Some air movement from the core to the exterior shell may thus still be necessary.

I would really appreciate Geoff's thoughts on all this... and some information on the BTU's per degree day per square foot of cooling and heating required for these structures. Somehow, 10" wide air spaces do not seem equivalent to 4" of closed-cell PU foam on a cold and windy night.

singh

I would like to see some form of this in residential applications.
Not a large structure as in an office building.
With some radiant wall tubing in betwen the double skin walls. For those cold and windy nights. I agree insulation will still be a necessary function for our northeast coast area.
Our upstate summers are short, perhaps this will work for natural cooling effect.
And I wonder if if tubes can then provide for enhanced cooling without worrying about condensation on interior .
Proper ventilation seems crucial between wall, to keep mold away.
I would like to hear thoughts from an M.E. also.

GMcD

Double skin facades

The double skin facade has been in use for a number of years on many European buildings and few in North America. You are right in that they work best with smaller/narrower floorplates for the natural ventilation aspect. The large North American style office building floor plates are "problematical". The double skin facades are a way of creating a high performance active facade with some sun shades and trickle vents. At night, dampers that seal off horizontal planes within the large air gap essentially create a thick equivalent to triple or quadruple glazing, depending on the climate zone.

I've seen a couple of the European buildings some years back, and have had some dealings with Transsolar, an energy engineering firm from Stuttgart who does design assist with these types of systems. They are best suited to buildings where some good exposures are present and a very detailed CFD analysis is done with the outdoor wind conditions and internal air movements. This is NOT a plug and play type system! You have to be very careful to get a controlled flow of ventilation through the occupied space in any kind of outdoor climate condition. I keep saying its all about the envelope - mechnaical engineers MUST be involved and learn the thermal dynamics of the building envelope and learn how to design passive systems to provide indoor comfort. Passive systems = low maintenance = long service life at low energy consumption. Gotta harvest all that free natural energy out there.

And yes, there are a number of low and high rise buildings with these double skins that have NO ductwork, use radiant slab heating/cooling, and a number of other neat energy saving tricks and devices, and they use 1/10 of the energy that a conventional "all-air" building uses, and they are more comfortable and have stable indoor temps year round. Can't say that for many all-air systems.....

There's more of the science and more case studies at:

http://www.buildingenvelopes.org/ and go to the Envelopes section and scroll down through all the papers and other stuff there. There is a thick (286 pages) paper from the Netherlands on the evaluation of these facade treatments for single storey buildings and smaller buildings that could be applied to homes/houses.

Weezbo

before i read the link...is this modeled like the Gotz building?

there were somany passive and active systems in synergy that i wanted to leave immediately to see if i could get a look at the mechanical blue prints ....i saw the scale model of the building and immediately considered many new vistas on the horizon of American designe of buildings...the next thing i read about was some place in Sanfrancisco....about a year or two later...