The Ice Is Right

Buildings Use Ice-Cooling Systems To Save Money On Air Conditioning During Summer

(AP)  As the summer swelters on, skyscrapers and apartments around New York will be cranking up the air conditioning and pushing the city's power grid to the limit.

But some office towers and buildings have found a way to stay cool while keeping the air conditioning to a minimum — by using an energy-saving system that relies on blocks of ice to pump chilly air through buildings.

There are at least 3,000 ice-cooling systems worldwide, according to state officials.

The systems save companies money and reduce strain on electrical grids, a huge benefit for New York City, which on hot summer days consumes more power than the entire nation of Chile.

It also cuts down on pollution. An ice-cooling system in the Credit Suisse offices at the historic Metropolitan Life tower in Manhattan is as good for the environment as taking 223 cars off the streets or planting 1.9 million acres of trees to absorb the carbon dioxide caused by electrical usage for one year.

Such a reduction in pollution is especially valuable in a city where the majority of carbon emissions come from the operation of buildings.

"If you take the time to look, you can find innovative ways to be energy efficient, be environmental and sustainable," said William Beck, the head of critical engineering systems for Credit Suisse.

Because electricity is needed to make the ice, water is frozen in large silver tanks at night when power demands are low. The cool air emanating from the ice blocks is then piped throughout the building, more or less like traditional air conditioning. At night the water is frozen again and the cycle repeats.

Ice storage can be used as a building's sole cooling system, or it can be combined with traditional systems to help ease the power demands during peak hours. At Credit Suisse, for example, the company must cool 1.9 million square feet of office space at the Met Life tower, a historic building that was New York's tallest in the days before the Empire State Building.

In the basement, three main cooling rooms house chilling machines and 64 tanks that hold 800 gallons of water each. Credit Suisse has a traditional air conditioning system, but engineers use the more efficient system first.

Trane Energy Services, the company that built the Credit Suisse system, said construction took about four months. Credit Suisse spent more than $3 million to renovate its cooling system.

The air-conditioning arm of American Standard, Trane also developed a system for Morgan Stanley's offices on Fifth Avenue and its facility in Westchester County.

A new Goldman Sachs headquarters also plans to install an ice cooling system. Credit Suisse is looking at installing the systems in offices around the globe, but nothing has been decided yet.

"The idea of not only saving money for large companies, but doing something that benefits the environment is win-win," said Todd Coulard of Trane's energy services department.

Engineers say the power-saving results from the system translate into millions of dollars saved in energy bills for the companies.

Ice storage at Credit Suisse lowers the facility's peak energy use by 900 kilowatts, and reduces overall electric usage by 2.15 million kilowatt-hours annually — enough to power about 200 homes.

At the Morgan Stanley facility in Westchester County, the system reduces annual peak energy use by 740 kilowatts and overall electricity usage by 900,000 kilowatt hours.

[retmilspouse]

Posted by BPalme at 02:24 PM : Jul 16, 2007

It uses less energy to blow cold air from the ice than for the air conditioner to cool the hot air and then circulate it. The air is already cold. I am not a scientist but that makes sense to me. Where am I wrong?

[nothappyatall]

"The idea that this method saves energy defies the laws of physics. Freezing the water to cool the air or cooling the air directly both take the same amount of energy."

Not necessarily, water that is already pretty cool doesn't take a lot to bring it's temperature down to 32 from say 60 or 65, so making the ice may take say 6 hours but then they get cool air from the melting ice for 16. If it lasts longer than to make the ice then there's an advantage, but pre 1900 air conditioning didn't exist and high rise office buildings DID, they opened windows for cross- breezes.
Trouble with people today is they come to figure they NEED air conditioning and want it 62 degrees in the room, but then when they go out the 80 degree day feels like 140- you gotta learn to ACLIMATE and very shortly you get used to a room that is not a 62 degree refrigerator.
People today are such whining brats- remember; before 1900 there was not only no air conditioning but most buildings and schools had GAS LAMPS for lights because the electric light bulb was not invented yet and the grid didn't exist till later.
Gas lamps made the rooms even hotter, but gee, people didn't seem to have a problem. Remember too- back in pre 1900 the women all wore HEAVY long dresses, petticoats and long sleaved blouses along with hats. The men all wore sdress uits and black hats, laborers wore work clothes and a hat.
Most men also had beards and all the women had long hair.

[hawksprings]

Even though it might not take any less electricity to do this, it could make a huge difference for the power companies by evening out the demand so they do have to ramp up their generators and then bring 'em down at night. Many rural electric co-ops will offer farmers who irrigate a break on their electrical rate if they will irrigate at night an not during the day for that very reason.

It would be like not having to run your car for 12 hours at 120 mph and then 12 hours at 10 mph, when you could run it at 60 mph round the clock.

...

[jimfinster]

BPalme:

I agree with your post. There would be no net reduction in electrical use. Although perhaps they can use more "green" electricity during off-hours?

[olebd]

Where's that FEMA ice?

[gunnerv1]

Global Warmimg--No frozen lakes--no ice

[mwhc1]

the old days used ice from lakes harvested during the winter... stored in ice houses insulated with thick walls filled with saw dust. that method would save electric power. freezing water at night just makes things so our old outdating grid can last another 10 years. hmmm... maybe not such a good idea after all.

[bpalme]

The idea that this method saves energy defies the laws of physics. Freezing the water to cool the air or cooling the air directly both take the same amount of energy. The ice method may save money if the cost of energy is lower at night since it's not peak hours. But the cost difference is only a cost difference per kilowatt that the energy company chooses to offer. Not a difference in the amount of energy used. Interesting the bad science that's being used in the whole green promotion. Like an electrified concert and a projected holograph of Al Gore to promote lower energy usage. Rather ironic. The idea that you really don't have to give anything up, like air conditioning, to be green, just change methods or buy credits.

[simpsonman19]

This is a pretty cool story, pun absolutly intended ;)

[nothappyatall]

Air conditioning as we know it wasnt even invented til around 1900, so people survived just FINE without air conditioners or electric fans for thousands of years.

[weareone2]

I hope this idea spreads. I'm interested in knowing whether this could be used for home cooling systems.

[neobrian-2009]

I worked at an ice plant when I was younger. Our drinking water was cooled by a coil,with ice chunks on top of it.It worked well,used no electricity.
We had produce trucks that we blew chipped ice on the crates of vegetables and fruit. It was the forerunner of Thermo King and other refrigeration units.
Maybe the old ways were not so bad.