Published on September 3rd, 2009 | by Susan Kraemer27
Chilled Water Cools MIT Physics Department
Here’s a very good example of simple tech that works efficiently. Because hot air rises, cool air falls down. So if chilled water is carried through tubes at the ceiling, it sucks hot air from a room; sending down the cooler air. Simple tech is often low carbon technology too.
Chilled beams use water to remove heat from a room. This is the opposite of radiant heating; in which pipes carry hot water in pipes embedded in a mortar for a stone or tile floor.
The potential reduction in fossil fuel use of using chilled beams instead of a traditional air conditioning system can be as much as 50%. “Chilled” is a bit of a misnomer; as the water doesn’t even need to be chilled. Even just running city water through this system will work as typical city water is about 55 degrees
Fahrenheit; enough to cool a 90 degree room. This works as a heat exchange.
If we used a system like this to cool every building we could achieve a cooling carbon reduction of 50% over 2009 levels. Fossil fuel use in heating and cooling buildings accounts for about 40% of our national carbon emissions.
This year’s climate bill contains incentives (Cap and Trade) for us to make reductions in fossil fuel use. Cap and Trade just means using fees (for choosing high carbon energy) to fund incentives (to help us buy low carbon energy).
The national building codes in the Climate Bill could do for the country what California building codes did for California: effortlessly cut our carbon footprint to half that of the nation: near European levels.
If you live near Boston, you can go check out how effective this innovative system is, and see if you can improve on the idea. The first installation is at MIT’s 49,000 square foot physics department; in buildings 4, 6, and 8, and next up is the new MIT Sloan School expansion and the David H. Koch Institute for Integrative Cancer Research.
“Chilled beams cool the people and dehumidify the air in the room. They take one-tenth the volume of fresh
air needed for traditional A/C, far less ductwork, smaller ducts, and smaller fans,” says David Cooper; manager of sustainability engineering and utility planning for the Department of Facilities.
This is a great passive cooling system for offices, laboratories, data centers and other spaces where equipment and sunlight generate a significant amount of heat.
“There’s a factor of eight improvement in cost of moving a Btu of air cooled by water versus air. If you can get the cooling energy into the space through water, you’re way ahead,” says Cooper. “The eight times factor is a very attractive alternative from an energy point of view.”
More ways to heat and cool our nation’s buildings to reduce our national carbon footprint: