groundwater cooling links

Sustainability at the cutting edge: emerging technologies for low energy (Google Books)

General explaination of possible systems

International Ground Source Heat Pump Association

Designing of a thai bio-climatic roof (paper)

I just came across this paper and thought the concept to be interesting, but not sure how it works...

Author(s)

WAEWSAK J. ; HIRUNLABH J. ; KHEDARI J.

Affiliation(s)

Energy Technology Division, School of Energy and Materials, King Mongkut's University of Technology Thonburi, Bangkok, 10140, THAILANDE

Abstract

This paper presents an innovative roof design. The roof is designed in response to the Tropical climate of Thailand with respect to human thermal comfort. It is composed of a combination of CPAC Monier concrete and transparent tiles on the outer side, air gap and another combination of gypsum with aluminum foil board and translucent sheets on the house side. It has two functions in operation: In daytime the roof acts as a solar chimney and induces natural ventilation. The transparent tile provides not only sufficient daylight for housing but also help in increasing the ventilation rate. In nighttime, the Thai bio-climatic roof plays the role of a roof radiator to dissipate the heat accumulated during daytime by long-wave radiation to the sky dome. The roof surface temperature decreases below ambient in several degree celcius. The cool air located between the two sides of roof flows downward providing nocturnal cooling.

high-profile metal brise soleil / scrim examples...

San Francisco Federal Building
New York Times Building
Seattle Art Museum
Santa Monica Civic Center Parking
Caltrans District 7 Headquarters
Palácio Gustavo Capanema
8 woningen Kettingstraat
DeYoung Museum
166 Perry Street

Other Materials:
Agbar Tower, Barcelona (glass)
WEA Trust Office Building (fabric)

Now for some concrete (mostly mid century stuff) & living vegetation examples...I just have to walk across the street for those!

Alternative Roof Forms for large Thai buildings

Hi Valerie,
Thanks so much for the solar model studies. I think this whole question of an appropriate roof form is going to be a major challenge for us. Here are some preliminary thoughts:
LOWER PITCHED ROOFS
- not very Thai, but are there precedents?
- lighter loads on the structure per m2
- shorter columns
- greater wind uplift
- greater risk of leaks
HIGHER PITCHED ROOFS
- more Thai, greater 'presence'
- scope for attics/mezzanine floors within roof space
- High walls or windows under high roof eaves (in gable walls, or high walls under mono-pitch roofs), adding cost and maintenance issues, but enabling better high level ventilation and daylight.
- Greater overhang and/or sun screens required on north side (assuming this is the higher
side in a mono-pitched structure) to protect facade from direct sunlight
- larger cross-walls required, with greater cost, need for piers or other stiffening
ISSUES FOR ALL ROOFS
- design of roof eaves on high and low sides of monopitch roofs to reduce wind turbulence and encourage cross ventilation.
- what is the optimum pitch of a monopitch roof to encourage cross-ventilation? This will need to take account of different conditions at different times of day and year. How is the 'stack effect' of such a roof reduced by thermal insulation in the roof? Maybe it's important to distinguish between quilt insulation and foil insulation (ie reduce UV transmission
rather than conducted heat).
-how is cross-ventilation effected by the width of a building, relative size of windward and leeward ventilation openings etc?
-How many of these variables can be tested by computer modelling?

Thinking About Radiant Cooling & De-humidification

It appears that geothermal technology is already being used in Thailand, and using radiant cooling through pipes in the floor/walls/ceiling is one way to complete the system. The water supply from geothermal pipes can also be connected into a more standard HVAC system. This Wikipedia article on heat pumps has a good summary.

A problem with radiant cooling is surface condensation. It is not clear if this has been addressed in the systems cited above. This house, which uses radiant floor heating and cooling, also closely regulates the floor temperature and uses "dry air delivered along its floors at ~68 degrees f all year-round (cf.: displacement ventilation). It uses a dehumidification coil and reheat coil in summer, and a heating coil in winter. In summer, the flow rate is sized for adequate dehumidification and fresh air" Are there less intensive ways to control condensation and humidity that would be viable in Thailand?

There are currently 2 ways to dehumidify air in buildings 1.) condense the moisture onto a cold surface (the same process that presents a problem with radiant cooling!) This is how air conditioning systems and small free standing dehumidifiers work...and the collected water can be re-used on site. 2.) machines that use desiccants (solid or liquid) to remove water vapor from the air--these are the same substances found in those little packets you find in your shoebox.

This is a simplified explanation. The following links are helpful:

HPAC Engineering
World Changing
Culture Kitchen

Radiant floor cooling @ Suvarnabhumi airport

The new Airport in Bangkok apparently uses in-floor pipes circulating water to cool the spaces adjacent to large windows to offset solar heat gain. I have read that such an installation may pose problems with condensation, but need to look into it more.

Some links:

Detail Portal for Architecture
JEC Thailand news