Alternative Climate Control (water cooling)

[Nowhereman1280]

Over one half of all domestic energy consumed in the US is used to heat or cool homes. Roughly one third of all energy consumed by Comercial buildings is used for heating or cooling.

Climate Control is one of the largest uses for energy in the United States, what can be done to reduce this cost?

This was moved over from the Aqua thread where it became terribly off topic.

It was suggested that the old freight tunnel system in Chicago be used to funnel cool lake or river water to the major buildings downtown where radiators and/or thermal transfer plates would be used to create cool air. This cool air would be used to air-condition the highrises.

Someone suggested that there already was a water cooling system like this in Chicago run by Unicom Thermal Technologies. However this is not a river or lake based water cooling system, but rather a "Chilled Water System." A chilled water system basically does the following:

Ice is made durring off-peak hours and stored in large quantities around a large grid of pipes, sorta like a radiator. Water is pumped through the pipes and chilled to about 34 degrees and pumped to buildings where it collects heat from another radiator system in the building. The building's radiator has a fan that blows air over it, cooling the air. The air is then used to cool the building.

Here is a picture of Unicom Thermal's flagship plant on State Street:



Other Info on Unicom Thermal:

http://www.bellgossett.com/Articles/files/case_10.pdf

http://www.kennyconstruction.com/underground/unicom.htm

http://www.aiachicago.org/special_fe...s/dba_005.html


There are some examples of river based water cooling systems both planned and already in existance.

There are several buildings that already use a system like this along the Chicago River, I am not sure which building utilize this technology however. If anyone knows or can find out, please share.

300 N. Lasalle, is planned to have a river-based water cooling system.

The EPA has, for at least a few years, refused to approve aplications for river based water cooling systems in Chicago because the amount of heated water dumped back into the river may have an adverse effect on the river ecosystem (and the green dye on St. pattys day will not?).

I have also heard rumors of buildings that do the same thing using lake Michigan water.

The only specific example I know of is soon to be demolished, it is the Jesuit Residence at Loyola University Chicago.



The only city wide lake, river, or ocean based water cooling system I know of is Toronto. It is currently still small, but is undergoing a massive expansion as ordinary bussiness has caught on that lake-cooling is much cheeper than paying the electricity bill.

Here's a picture of one of the new pumping stations being built for this system in Toronto:



An article about the system:

http://www.canada.com/topics/news/na...d388ed&k=89467



Discussion about any other heating or cooling technologies is welcome in this thread, some examples include:

Lake, river, or ocean cooling
Geo-Thermal cooling
Geo-Thermal Heating
Any other non-fossil fuel based cooling or heat source

[Neuman]

The article doesn’t explain how the Toronto system works. Whether cold water is pumped form the lake inland and directed to each building and then returned, or does a liquid pass through a closed circuit system transferring just the cold from the depths of Lake Ontario. I would think it’s the latter....

[brian_b]

I brought up the Toronto system in the Aqua thread. I remembered reading about it a few years ago on Slashdot...

I was way off as far as how the system worked though. I just did some searching and found the link.

They built a deep-water intake system and are drawing water in at 4 degrees C. It is filtered, run through heat exchangers (this is where they get the cooling effect), treated, and sent on as drinking water.

An excellent diagram of the system:
http://www.enwave.com/enwave/dlwc/

Essentially, they replaced their drinking water intake system with one that brings in super-cold water and got two uses for the water for the price of one.

[Xelebes]

Now how about heating?

[Nowhereman1280]

Originally Posted by brian_b

I brought up the Toronto system in the Aqua thread. I remembered reading about it a few years ago on Slashdot...

I was way off as far as how the system worked though. I just did some searching and found the link.

They built a deep-water intake system and are drawing water in at 4 degrees C. It is filtered, run through heat exchangers (this is where they get the cooling effect), treated, and sent on as drinking water.

An excellent diagram of the system:
http://www.enwave.com/enwave/dlwc/

Essentially, they replaced their drinking water intake system with one that brings in super-cold water and got two uses for the water for the price of one.

I'm sorry I must have missed it when you brought it up over in the Chicago thread.

Anyhow, nice work in finding out a bit more about it, what a good idea, warm up your drinking water to a temperature that is bearable to drink by airconditioning your buildings! Its an even better system than I thought.


Anyhow, Xelebes, when it comes to heat you can't really use water, but you can use Geo-thermal heat, especially in places that are closer to volcanic activity.

The best example of volcanic Geothermal heat I know of is Iceland, since it is basically a giant volcano, much of the country uses Geothermal heat. This is a geothermal plant in Iceland that collects heat to send to Reykjavic.



For any further info on the mechanics of it, just go to howstuffworks.com and search for Geothermal Heat, and they have a detailed description of the mechanics of it.

Apparently there is also a way of getting heat even from the relatively cool ground we in the midwest live on. Its pretty complicated and I don't really get it, but somehow it can condense the heat of 54 degree soil into 70 degree air, here's a wikipedia entry about it:

http://en.wikipedia.org/wiki/Geother...ange_heat_pump

[Neuman]

I wonder what the avg. water temp is for water being pumped from Lake Michigan at the off shore intake cribs? Not sure we could use the water for drinking in the same duel role in Chicago. The reason for this is the filtration plant is already next to the lake at Navy Pier. We would have to move the water further West than bring it back East to clean it and then have to pump it West again.... Though as I pointed out in the Aqua thread, the intake cribs are under used as it is and one of them could be reconfigured for this type of use. I can definitely see this as a viable future project in Chicago.

[brian_b]

I don't think that the intake cribs in Chicago could be used. Lake Michigan is very shallow in the Chicago area

The Toronto system claims that the intake pipes are at a depth of 83 meters.

Looking at the Lake Michigan bathymetry viewer on NOAA's website, Lake Michigan reaches a depth of 80 meters about 27 miles off Chicago. It takes 2.5 miles just to reach a depth of 10 meters!

While Lake Michigan ultimately reaches greater depths than Lake Ontario, it has a shallow shelf on the southwestern tip.

[Nowhereman1280]

Originally Posted by brian_b

I don't think that the intake cribs in Chicago could be used. Lake Michigan is very shallow in the Chicago area

The Toronto system claims that the intake pipes are at a depth of 83 meters.

Looking at the Lake Michigan bathymetry viewer on NOAA's website, Lake Michigan reaches a depth of 80 meters about 27 miles off Chicago. It takes 2.5 miles just to reach a depth of 10 meters!

While Lake Michigan ultimately reaches greater depths than Lake Ontario, it has a shallow shelf on the southwestern tip.

Yes, Lake Michigan near Chicago is shallower than Ontario, but I don't think there is that much difference in temperature between 10 meters deep and 80 meters deep. While I know there will obviously be some difference, I don't think that it will make enough of a difference that it wouldn't be cold enough to use as a coolant. Its really only the first five or ten feet of the lake that is affected by sun and seasonal temperature changes, everything below that stays below 55-60 degrees all year long, so at 2 or 3 miles out, we could bring in water cool enough to provide AC for our office buildings.

[bosmausasky]

Only the most efficient buildings produce ice after hours to cool the building. Some buildings just cool the water during the day.

The WTC used Hudson River water for cooling

[Nowhereman1280]

Originally Posted by bosmausasky

The WTC used Hudson River water for cooling

Really? How much of WTC used it? That suprises me considering the size of those buildings, I would think the kind of office heat generated by that kind of heat output would compromise whatever ecosystems manage to survive the pollution...

If anyone has more detail on this, please post it here.

[bosmausasky]

World Finanical Center also uses it:
Cooling is provided by chilled water supplied from a central cooling plant. Uniqueto the system is that river water is used to provide a direct cooling source for up tofour months per year. When mechanical cooling is needed, the river water will carrythe rejected heat, thereby eliminating the conventional cooling tower plant.The mechanical cooling plant integrates three million gallons of chilled water whichis stored in the lower section of FOUR WFC. This stored chilled water is used duringpeak demand periods to reduce site wide operating costs. The thermal storage tanksare replenished each night when electric rates are at their lowest. Are conditioningsystems are decentralized and consist of single floor variable air volume systemswith an internal water reclaim circuit

[kalmia]

[Neuman]

Now we just need a formula that gives us temperature based on water depth...

[brian_b]

Originally Posted by Nowhereman1280

Yes, Lake Michigan near Chicago is shallower than Ontario, but I don't think there is that much difference in temperature between 10 meters deep and 80 meters deep. While I know there will obviously be some difference, I don't think that it will make enough of a difference that it wouldn't be cold enough to use as a coolant. Its really only the first five or ten feet of the lake that is affected by sun and seasonal temperature changes, everything below that stays below 55-60 degrees all year long, so at 2 or 3 miles out, we could bring in water cool enough to provide AC for our office buildings.

Well, you have the right idea. It turns out that water is most dense at 39 deg F (4 deg C), so it sinks to the bottom. In the summer, there are really 3 distinct layers in a deep lake - you have the hypolimnion at the bottom (a constant 39 degrees), the thermocline, and then the epilimnion at the top. The thermocline tends to prevent the warm top and cold bottom layers from mixing. In the spring and fall, changes in the water temperature cause everything to get all mixed up and you have the colder water on top and warmer water on bottom. To make matters even more complicated, the shallow shelf in the southwest of Lake Michigan forms a thermal barrier between the shallow water and the surface water in the deeper parts. Basically, the water around Chicago tends to get warmer faster.

What you really want for water cooling is a constant cold water source. As close to freezing as possible yet never needing to worry about frozen water. That's why Toronto has their pipes so deep - they are able to draw from the hypolimnion layer in Lake Ontario. Lucky them that it gets so deep so fast.

I can't find the data that suggests where Lake Michigan's summer hypolimnion layer starts, but to be effective in Chicago you're going to want to be drawing water from below that point.

55-60 degree water is not going to absorb a whole lot of heat. I'm not sure it would be cost effective to build a system if that's all the temperature delta you're going to get!

[Young Gun]

It pulls heat from the 59deg ground the same way that a heat pump draws heat from exterior air. It is more efficient than a heat pump because it isn't drawing heat from as low of a temperature. Basically it is an airconditioner that works in reverse, placing cold outside and warm inside.

[Nowhereman1280]

Quick Update.

Chicago Spire is going for Gold LEED certification which means that, assuming its built, it will use river water for cooling.

300. N. Lasalle in Chicago is also going for LEED Certification and will also use the river...

[honte]

^ I talked to someone about this recently... they claim that you can't just take the river water, use it, and discharge warmed water back into the river. 300 LaSalle was supposed to be the "last one." The solution is to dig wells and discharge the warmed water into the well, letting the heat be absorbed by the earth before it returns to the river at a normal temperature.

Anyone hear of this challenge/complication before?

[AZheat]

I just watched an excellent documentary that touched on this subject this morning. I'm sorry I can't remember the title. They mentioned several building techniques that are being used. One idea is to place a garden on the roof that covers most of it. This reduces the heat island effect and it also allows much of the rainwater to be captured by a drainage system which uses it for air conditioning, etc. New designs also get the most light possible from the sun which helps eliminate alot of unnecessary electric useage. I believe they said it reduced it by about a quarter. Advances in the technology of windows was also mentioned as well as more efficient interior lighting that turns off when the workers leave the room automatically. There's also alot of water when it rains that ends up in storm sewers and picks up all sorts of dirt and contaminants which cause problems. It's much more efficient to try to capture as much of this runoff as possible. There's a house here in Arizona in a remote location that supplies 100% of his family's water needs by capturing all of the water from the roof when it rains and storing it in several very large buried containers. It's filtered before being used and is an example of how even a single family home can make the most of a scarce resource.

[Nowhereman1280]

Originally Posted by honte

^ I talked to someone about this recently... they claim that you can't just take the river water, use it, and discharge warmed water back into the river. 300 LaSalle was supposed to be the "last one." The solution is to dig wells and discharge the warmed water into the well, letting the heat be absorbed by the earth before it returns to the river at a normal temperature.

Anyone hear of this challenge/complication before?

Yes actually, there is a building in Milwaukee Wisconsin that uses a slightly different version of this. Its called the Schlitz Audubon Center and is a nature park on lake Michigan.

Here is how they describe it on the website:
"A geothermal heat system that uses 90 groundwater wells and the earth’s temperature to provide heating and cooling, lessening dependence on fossil fuels"

Basically they drill a lot of wells and pump the water through pipes in them to leech the heat into the ground which is a constant 56 degrees Fahrenheit year round below 6 feet.

For some reason this building only qualified for LEED Gold, though I would have thought it could have gotten Platinum. Take a look, its an interesting read:

http://www.schlitzauduboncenter.com/buibio.htm

[honte]

^ Thanks for the reply. The groundwater well kind of system, or just a vertical ground well, for a geothermal exchange is not really a new idea; I think that's what they're up to in Wisconsin. They use groundwater wells a lot in the northeast, from what I've heard.

What I am referring to is more of a city regulation - that you can't just dump the "spent" water back into the river due to fears that there will be some heating / impact on the ecology of the river. (The studies I've seen indicate that there would be little, if any, impact.) Otherwise, there would be no reason to do the well. So, I'm wondering if this is just a rumor, or if the city is really requiring it?