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View Full Version : Using ice instead of air conditioners to cool buildings



ckb2001
07-25-2007, 01:35 PM
I had no idea this was already being done, but it's not only an obvious idea, it's far more environmentally friendly. Maybe the idea should catch on elsewhere:

http://www.cnn.com/2007/TECH/science/07/24/ice.cooling.ap/index.html

"Some office towers and buildings are keeping their AC use to a minimum by using an energy-saving system that relies on blocks of ice to pump chilly air.

The systems save companies money and reduce strain on the electrical grid in New York, where the city consumes huge amounts of power on hot summer days.

Ice cooling also cuts down on pollution. A system in Credit Suisse's offices at the historic Metropolitan Life tower in Manhattan is equal to taking 223 cars off the streets or planting 1.9 million acres of trees to absorb carbon dioxide from electrical use for a year, according to the New York State Energy Research and Development Authority."
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cnc66
07-25-2007, 01:58 PM
interesting... I would not have thought freezing the water would be cost effective... it certainly improves the burdon on the power grid.. I wonder if the also get a rate break because of the off high demand times they operate.

This is not new stuff btw, when I was a kid, we had a round fan, kinna like a hassock, something you could put your feet on while sitting. It had a reservoir on top for ice.. the fan would blow upwards onto the "cone" of the cold reservoir changing the airs direction to horizontal and into the room. Condensate was a pain, but in the days before we had any A/C is was worth the agravation.

I also used to have a fan that forced the air into wedge shaped flues that narrowed, slightly compressing the air, the heat was absorbed by the aluminum flues and as it flowed past the constriction, it expanded slightly thus cooling... an aside, the Arabs have designed window openings like this for 600+ years.

Eshlemon
07-25-2007, 02:10 PM
I had no idea this was already being done, but it's not only an obvious idea, it's far more environmentally friendly. Maybe the idea should catch on elsewhere:

http://www.cnn.com/2007/TECH/science/07/24/ice.cooling.ap/index.html

"Some office towers and buildings are keeping their AC use to a minimum by using an energy-saving system that relies on blocks of ice to pump chilly air.

The systems save companies money and reduce strain on the electrical grid in New York, where the city consumes huge amounts of power on hot summer days.

Ice cooling also cuts down on pollution. A system in Credit Suisse's offices at the historic Metropolitan Life tower in Manhattan is equal to taking 223 cars off the streets or planting 1.9 million acres of trees to absorb carbon dioxide from electrical use for a year, according to the New York State Energy Research and Development Authority."
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Good plan, now we don't have to worry about melting ice caps raising sea levels. Just put all the ice in buildings.:)

Has some potential but needs to be closely monitored, my region is already suffering from drought. Putting ice in buildings ain't gonna help any. CKB2001 you're a science guy, is there something else (non-toxic) that could be used in a similiar means the ice is?

ckb2001
07-25-2007, 02:45 PM
Good plan, now we don't have to worry about melting ice caps raising sea levels. Just put all the ice in buildings.:)

Has some potential but needs to be closely monitored, my region is already suffering from drought. Putting ice in buildings ain't gonna help any. CKB2001 you're a science guy, is there something else (non-toxic) that could be used in a similiar means the ice is?

Well, there are many non-toxic methods of transferring heat, but which are cost-effective requires more than general science knowledge. You need to know something specific about that type of technology.

But, sure in general you can cool homes or buildings in a multitude of ways. You can use the same kind of system astronaut suits use to transfer heat by using water instead of air. The goal in that kind of system would be to let the water circulate from warmer areas inside the building to say cooler areas underground. The same kind of system can be used to heat the building in winter. That's essentially what geothermal heating/cooling comes down to.

And just like water evaporating off your body (after say a swim) cools you down, you can use evaporative cooling for buildings.

Then there are other things, like using energy-efficient windows or planting trees on the roof. Apparently, the savings aren't trivial when doing either.

So, there are many ways of cooling buildings that are non-toxic, but what I can't tell you is which is the most economical. The idea in that article (ice) is obviously an old idea. I just had no idea it was in use because while the technology is old, that doesn't mean the economics support its use. Apparently it does.

arsenal
07-25-2007, 02:50 PM
refrigerators and freezers use the same components/systems as air conditioners...

so you can use that energy making the ice to cool the office, or you can just use that energy to cool the office with an AC...

Eshlemon
07-25-2007, 02:50 PM
Well, there are many non-toxic methods of transferring heat, but which are cost-effective requires more than general science knowledge. You need to know something specific about that type of technology.

But, sure in general you can cool homes or buildings in a multitude of ways. You can use the same kind of system astronaut suits use to transfer heat by using water instead of air. The goal in that kind of system would be to let the water circulate from warmer areas inside the building to say cooler areas underground. The same kind of system can be used to heat the building in winter. That's essentially what geothermal heating/cooling comes down to.

And just like water evaporating off your body (after say a swim) cools you down, you can use evaporative cooling for buildings.

Then there are other things, like using energy-efficient windows or planting trees on the roof. Apparently, the savings aren't trivial when doing either.

So, there are many ways of cooling buildings that are non-toxic, but what I can't tell you is which is the most economical. The idea in that article (ice) is obviously an old idea. I just had no idea it was in use because while the technology is old, that doesn't mean the economics support its use. Apparently it does.

I should have specified, was looking for a substance to replace the water/ice in the buildings cooling process for instance.

ckb2001
07-25-2007, 03:06 PM
I should have specified, was looking for a substance to replace the water/ice in the buildings cooling process for instance.

Oh, I see. Well, my guess is water would actually be one of the best materials to use because it has a very high specific heat/ heat capacity. What that means is it can absorb or lose large amounts of heat without changing temperature too much, which is desirable if you want to transfer heat.

I know there are materials with higher heat capacities, but water is cheap and abundant, so I'd actually be surprised if something else was more economical in this particular technology.

ckb2001
07-25-2007, 03:14 PM
refrigerators and freezers use the same components/systems as air conditioners...

so you can use that energy making the ice to cool the office, or you can just use that energy to cool the office with an AC...

Yeah, but apparently, they use less energy to make the ice because it's done at night. Of course, that also saves money since power demands are low at that time.

From the article:

QUOTE:
" 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, officials said.

At the Morgan Stanley facility in Westchester County, the system reduces peak energy use by 740 kilowatts and overall electricity usage by 900,000 kilowatt hours annually."
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arsenal
07-25-2007, 03:43 PM
Yeah, but apparently, they use less energy to make the ice because it's done at night. Of course, that also saves money since power demands are low at that time.

From the article:

QUOTE:
" 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, officials said.

At the Morgan Stanley facility in Westchester County, the system reduces peak energy use by 740 kilowatts and overall electricity usage by 900,000 kilowatt hours annually."
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ahh woulda helped if i read the article...

and now i did and i understand better, im in the HVAC field and was thinking of it in a different light... sounds pretty pricey though and i wonder how they "piped" (circulate) the cool air throughout the entire building... interesting

Eshlemon
07-25-2007, 06:04 PM
Oh, I see. Well, my guess is water would actually be one of the best materials to use because it has a very high specific heat/ heat capacity. What that means is it can absorb or lose large amounts of heat without changing temperature too much, which is desirable if you want to transfer heat.

I know there are materials with higher heat capacities, but water is cheap and abundant, so I'd actually be surprised if something else was more economical in this particular technology.

Corn was cheaper before being used as ethanol, do you want to go down that path with water? And the abundancy is a regional issue, guess towns next to oceans can suck in all they want unless salt waters not an option in that the heat/heat capacity thingy.

ckb2001
07-25-2007, 08:06 PM
Corn was cheaper before being used as ethanol, do you want to go down that path with water? And the abundancy is a regional issue, guess towns next to oceans can suck in all they want unless salt waters not an option in that the heat/heat capacity thingy.

The article says one such building has 64 tanks, each holding 800 gallons of water (51,200 gallons of water total). The water in those tanks is probably bought once. You don't have to add new water constantly, at least not in theory.

So, considering it's a one-time investment, and considering how much is saved, I think it's a no-brainer. Let's see, the article says:

QUOTE:
"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, officials said."
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Just looking at a rough estimate, the average US home uses the energy equivalent of 1,253 gallons of oil per year (http://www.plu.edu/~mast/international/042707-fast.html), and you need about 0.5 gallons of water to process 1 gallon of oil. So, that means you haven't used 125,300 gallons of water that would have been used by the 200 homes, and instead used 51,200 gallons of water, thus saving ~74,000 gallons of water.

OK, obviously, that's not a complete analysis (nowhere close - not all the energy used by a home comes from oil and the process of extracting oil, refining it and using it uses far more water, etc..), but it's shows you may actually be saving on the amount of water used in addition to whatever advantages from an environmental perspective we're talking about.


And remember, this is a process that makes economic sense for large corporations, reduces pollution, uses less energy overall, etc.. So, even if the price of water were to increase slightly, I do think it's worth it. But, as stated, I don't think it's necessarily true you are using more water than you otherwise would have.

Eshlemon
07-25-2007, 09:54 PM
The article says one such building has 64 tanks, each holding 800 gallons of water (51,200 gallons of water total). The water in those tanks is probably bought once. You don't have to add new water constantly, at least not in theory.

So, considering it's a one-time investment, and considering how much is saved, I think it's a no-brainer. Let's see, the article says:

QUOTE:
"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, officials said."
-----------------

Just looking at a rough estimate, the average US home uses the energy equivalent of 1,253 gallons of oil per year (http://www.plu.edu/~mast/international/042707-fast.html), and you need about 0.5 gallons of water to process 1 gallon of oil. So, that means you haven't used 125,300 gallons of water that would have been used by the 200 homes, and instead used 51,200 gallons of water, thus saving ~74,000 gallons of water.

OK, obviously, that's not a complete analysis (nowhere close - not all the energy used by a home comes from oil and the process of extracting oil, refining it and using it uses far more water, etc..), but it's shows you may actually be saving on the amount of water used in addition to whatever advantages from an environmental perspective we're talking about.


And remember, this is a process that makes economic sense for large corporations, reduces pollution, uses less energy overall, etc.. So, even if the price of water were to increase slightly, I do think it's worth it. But, as stated, I don't think it's necessarily true you are using more water than you otherwise would have.

Sounds even better now after going over any possible negative consequences.