Comparison of Sea Water-cooled AC With Other Types of Cooling Method.

Perhaps consider the heat that is added to the ocean micro-ecosystem.

Thanks!

That sounds a good idea for the aspect of environmental friendly.

May I have some keywords for searching related inf. ?

I did search impact of micro-ecosystem for sea water-cooled air-conditioning sys, but it doesn't work.

First of all these different types of A/C systems are site and size specific, where one choice may be well suited to the application, and another not...so your comparison makes no sense as there is no context....

SWAC

http://www.tsi.com/uploadedFiles/_Site_Root/Products/Literature/Handbooks/2980245C-HVAC-Handbook-2013-web.pdf

U're right!

However, I got no context for this assignment, just simply do the comparison in my part. I will give an assumption context for a practical case to do another comparison.

Seawater is quite aggressive towards piping and system components, so you will end up using some exotic materials like GRP piping and naval brass. Also, you need to keep various grobblies out of your cooling water circuit, like crabs, jellyfish and barnacles. Further, you may need to treat the water to prevent fouling by various dissolved materials.

At least you won't have the problems associated with an air/water cooling tower, like keeping legionella out of it, and arranging for blowdown.

Thanks!

I wonder why the risk of legionella disease will be avoided??

Air-cooled conditioning system also gives a sealed chilled cycle, is that right??

Legionella is only going to appear in systems with high stagnation rates. The colonies begin under sediment, that gets stirred up in an open circulating cooling system (cooling tower), and carried into the mist particles at the fan ducts.

Seawater cooling is a once-through system as such, and is not generally subject to the same conditions.

The legionella is not likely in the cooling liquid in any case. That part of the system is sealed up and not exposed to the circulating air. Usually the legionella issue shows up in drip trays underneath spot cooling heat exchangers or in low points in ducting where moisture condenses and collects. It could be bad though in a swamp cooler.

Yes, that is one manifestation of it.

Understood!

It is lucky to be here, I learnt a lot!

Thanks!!

And yet people and businesses spend a fortune every year installing them because they work so well everywhere else only to find that about December they have depleted their soil thermal reserves and it back to the old heating systems they had before.

One of the biggest ones I am aware of is at the local University. About 7- 8 years ago they spent a fortune to put in a huge geothermal systems to heat and coo the whole complex so they could get rid of their old NG and coal fired central boiler building that's over 100 years old.

To this day if a guy watches starting around mid December until near the end of the college season that old boiler system is just chugging away like it did for the last 100 plus years.

Rumor from one of the people I met once who works at the college in the maintenance dept said the first winter when their high end guaranteed to go geothermal system bottomed out they would run the old boilers flat out all night until just before sunrise to build up the geothermal systems reserves up for the day so that in the day time it looked like the geothermal was doing the job and the old boiler building was shut down.

From what bonehead stuff have seen first hand that university threw money at and then promptly failed on I would totally believe the story.

Personally I think they should have took their stupid multi million dollar football field renovation money and put a massive solar thermal heat collection system in its place and used that to load up the geothermal heat reservoir any time the sun was shining so it had a viable heat source to pump out of all winter.

The subsidy miners and subsidy engineers probably couldn't figure out how to divvy up the grants.

OR they could have installed a tire burner.

Thanks!

It will be a great material for the further case study.

What is the investment cost for a typical SWC for a 50-storey commercial building??

Your question reveals that you have done no research on the subject.

That should have been your first exercise, before coming to any forums to ask for help.

Had you done some research, you would already have a longer list of pros and cons, harvested from the MANY papers, articles and literature available on the internet.

The main advantage is the lower specific heat capacity of seawater.

Now, go do some research!

Come back if you need help with advanced theories and knowledge that you have obtained by doing the research yourself.

I know my background knowledge of this topic is basic.

I did some research in Scopus and web of science before I'm here, but I can't get what I wanted.

For example, the material used for anti-erosion, types of sea water-cooled condenser which can be maintained separately (some parts of the condenser which contact with sea water directly can be replaced separately instead of to remove the whole), the maintenance cost of different types of cooling system. I just get the idea but have no further information on it.

Most resources I found is about general information and some of that are likely to be useful, however, it takes about $30 US to but the authority, poor me.

For example: Porak, DN (Porak, Dustin N.) ; VanZwieten, JH (VanZwieten, James H., Jr.); Wiles, B (Wiles, Benjamin) (2013), An Analysis of Florida's Sea Water Cooling Resource, MARINE TECHNOLOGY SOCIETY JOURNAL

Well, I live in West Tennessee, so I think the cost of seawater coolant would be prohibitive .

Try a search for the US Navy Machinist's Mate rate training manuals. They have a section on air conditioning. They have been using sea water cooled condensing units for a very long time.

Not only the USN, but any reputable navy throughout the world have obviously used sea water cooling systems for all their ships, on all manner of systems, whether that be military or merchant navies.

Consider that all (big) boat's engines are SW cooled.

As far as I know, different metals are used depending of temperature to avoid fouling, but it works

Some powerplants are also on the sea shore ansd use SW to cool.

Their experience could be useful for your project.

Slow speed marine engines on large ships are cooled with a manufacturer's prescribed coolant which in turn is cooled by sea water in an heat exchanger, as is the majority of other marine machinery that requires any cooling processes including the subject of this topic refrigeration/air conditioning........the evaporators (tube type heat exchangers) used in these systems are sea water cooled and in the main have tube nests of 90/10 cupro-nickel if the sea water flow rate is kept below 3m/s, if the flow rate happens to be over this 70/30 cupro-nickel is used (uncommon), or they can use titanium plates in plate type heat exchangers.

Cupro nickel exhibits the good heat transfer properties required and also resists fouling and corrosion/erosion.

Good answers, the 90/10 alloy is the cheaper and softer of the two cupro-nickels used.

It is also apparently more subject to wear erosion due to system vibrations of supports against tubes (near tube plates out in the middle of a condenser or heat exchanger).

The unit in question also had experienced issues with really bad boiler makeup from an improperly designed and operated evaporator that produced water with a pH of about 4.8

If it were me doing the project, I would pose a lot of questions to the fine folks that build desalination plants. Having worked with them quite a bit, I pretty much know the answer before I ask it.

Bar none, the best in the world at that discipline are the Israelis. They have pretty much overcome the restraints on materials used to build the plants.

If you want to overcome limitations, talk to the people that know the limitations involved and how to work around them.

On the environmental side of your project, too many things are still in a state of flux, and are being promoted via voodoo engineering.

As a side note, there is a much cheaper way to attain cooling than Sea Water or other applications. Take a moment to think about it, and it will present itself. Think groundwater. In my case a 3800 square ft. house in Arizona that is cooled for around $35.00 a month versus $400.00 a month by my neighbors. There is no such thing as a panacea, only creative solutions to issues presented. It helps if you have a background in the discipline you are using to solve a problem. I do not have a background in HVAC, but my idea beats everybody else's hands down. It is something to think about.

So you take the ground water and put it through a fan coil unit or heat exchanger and use the cold air or water to cool your home ? What is the inlet and outlet temp of the groundwater ? What do you do with this water after it runs through your system ?

Initial cost? Do you have your own well?

In general terms, where are you located?

A major con is biological fouling. The nuclear industry found that heat exchangers in some areas would plug solid in short order due to proliferation of zebra clams in cooling systems. What grows in your water?

Zebra mussels are fresh water.

https://en.wikipedia.org/wiki/Zebra_mussel

It must have been some other aquatic zebra you were referring to. I agree with the statement about fouling due to slime, and macro-organisms.

You are right that zebra mussels were an issue on the great lakes. My main experience was with emergency cooling hardtanks, where we regularly had to boil out the tank and then go in and manually chisel out the marine growth and replace zinc anodes. Usually, the seawater systems had an oversize allowance for marine growth and add cleanouts to go in and mechanically remove the critters.