replacing the air cooled to centrifugal chiller.

[Tommy knocker]

2.3 years will cover the cost of a tower, piping, pumps, chemicals, etc? Go for it.

[jayguy]

You guys just love to argue. Evidently youve never seen someone try to beat a bore brush through a tube and bust it. You think its easy because you have a tube machine and skills. Take a half wit with an adjustable and some rods and brushes and have at it. Good luck

Sent from my ERIS using Tapatalk 2

straight rods only? that would suck.

[mikeacman]

+1 on the centrifugal payback and understand ....

You WILL HAVE TO maintain all the added equipment and have CONSISTENT and CONTINOUS water treatment being performed at ALL times on both sides , chilled water and condensor .

as far as punching tubes consider getting a self brushing system that reverses flow every xxx hours and keeps your tubes clean ...which keeps your kw per ton down...

let your water get trashed and you'll lose your savings in a hurry....it doesn't take years to happen ...i seen tubes fouled in days without proper water treatment ...

as far as a brand I would go with what is best supported by factory reps / mechanics in your area ...

On the other hand .....

That machine goes down you have no cooling ...

You lose a fan motor on an air cooled you have wiggle room ....

You have multiple screws and lose one you have wiggle room

If your going to follow a strict maintenance regimen I would still say centrifugal ...

If your gonna run it till it quits I would say air cooled

[dlove]

+1 on the centrifugal payback and understand ....

You WILL HAVE TO maintain all the added equipment and have CONSISTENT and CONTINOUS water treatment being performed at ALL times on both sides , chilled water and condensor .

as far as punching tubes consider getting a self brushing system that reverses flow every xxx hours and keeps your tubes clean ...which keeps your kw per ton down...

let your water get trashed and you'll lose your savings in a hurry....it doesn't take years to happen ...i seen tubes fouled in days without proper water treatment ...

as far as a brand I would go with what is best supported by factory reps / mechanics in your area ...

On the other hand .....

That machine goes down you have no cooling ...

You lose a fan motor on an air cooled you have wiggle room ....

You have multiple screws and lose one you have wiggle room

If your going to follow a strict maintenance regimen I would still say centrifugal ...

If your gonna run it till it quits I would say air cooled

I agree, well said

[moideen]

Thanks your replay,
The chemical treatment and additional centrifugal maintenance cost has also included in the comparison report of air cooled and water cooled system from Mitsubishi. For your reference, please find the attached report from Mitsubishi. But do not include the overhauling charge of compressor. (As per MHI service department recommendation, every 7 year, compressor has to be overhauled) recently we have overhauled 1500 ton capacity MHI compressor, cost is 463531 AED (126182 USD)!!. Now RTAA chiller compressor is failing after 14 years, before it don’t have major maintenance, only replaced some display boards, the authorized Trane service department can remanufacture the compressor by charging 50000AED(13611 USD),but we are the energy save by using water cooled centrifugal.
Any way we are looking the same proposals from York and trane.

Thanks
Moideen-Dubai

[KnewYork]

You might want to consider another manufacturer. I know of one (York) that does not require any scheduled overhaul interval and I have seen many compressors run over 75,000 without ever being opened.

[ga1279]

My apologies to one and all as I jumped the gun with my last post, I did not realize the area we were discussing. Water treatment will be costly as your make-up water will be high and fresh water is costly there to begin with. 14 years of life out in that climate, hell I've seen them in Houston that don't last that long.-GEO

[motoguy128]

That's a matter of opinion.

That's a matter of water treatment. With good water treatment, I've heard of units going year without beign brushed.

Cooling towers in many climates need to be cleaned as often as condenser coils.

[dlove]

I don't understand how the pay back can be the same for both systems. I also, would not bet on the ROI to be 3 years. If they agree to get payed over the the time period they say it will take to get your ROI then they would have a vested interest in making sure they were right. (don't hold your breath) Every time i hear 3 year ROI i double it. I would forecast the next 5 years of water cost and electrical cost. if cost of water, and electrical goes up this would effect the ROI period. Unless you already added in the increases. DO you pay for sewage waste?

Also, are there any other buildings in your area that has water cooled and are about the same size as yours? If so i would talk with them and get their input. Not sure of the water chemistry but, depending on the type of water you have towers can be the bane of your life.

Personally i would stay with what you have and make repairs. I would imagine the capital cost comes out of your bottom line. Do repairs come out of common charges? if so why would you dump all that money in a new system? Just wondering, I would think if you took that money and properly invested it, the return would be greater than what you make on the savings over the next three years. -just saying. The ROI will always be there, whether you do it now or later. Unless they are making you a deal you cant refuse.




anyway not to get to far off track. Overall not knowing all the little details. Unless the entire systems is failing i would make repairs. If you have the money and just want to save money and they really believe they can get you a 3 year ROI, Then that's great, all new equipment today will save money, much has changed over the last 10 years. But again, Who can support for the equipment your will buy. If there is no local support for this new equipment or there are only a few who can work on it, i would shy away.

[supertek65]

i will be the idiot here!

what is an MHI chiller?????

[Dallas Duster]

i will be the idiot here!

what is an MHI chiller?????

ok I think it's the panel on the chiller.

[flange]

If I were bidding this, I would look at a third solution. With the amount of runtime they get over there verses our traditional cooling season, payback can occur more quickly. we have less degree days for cooling, I would think by a lot. At any rate, if I had the infrastructure in place for RTAA's, I would look at a repalcement using either screws or turbocore, using evap condensing, with all pumps, evaporater, tower etc, all bundled neatly into one package, and set it in place of those rtaa's. you will see similiar kw/ton performance, and less initial cost, but thats just me. payback would be sooner, with less water treatment involved.

[flange]

but what do I know?