Converting air cooled to water cooled

[basprofessional]

I'm in the process of upgrading a condenser for some coolers. I've thrown the idea of going water cooled at the customer. Does anyone know what the operating savings would be going from air cooled to water cooled?

[MikeySq]

I guess it really depends on how much the water will cost!

Mike

[icemeister]

Are you referring to water cooled units with recirculating tower water or once through city water or well water?

Once-through city water is usually cost prohibitive and possibly illegal. Using well water may also be restricted.

Back in the old days, we had combination air & water cooled units which allowed for straight air-cooled operation from about 75ºF and below. Above that, the water cooled condenser's regulating valve would modulate to hold around a 105ºF condensing temperature.

[crymtide]

Without an unlimited supply of well water there would be huge costs instead of any savings

[dave sulz]

We usually change water cooled to air cooled.

[basprofessional]

What I meant was a small cooling tower recirculating the water. The water is reclaimed so the cost is minimal as far as water goes. I’m curious about the electrical cost with lower head pressures. Does anyone have an idea what the lower electrical KW would be?

[VTP99]

I’m curious about the electrical cost with lower head pressures. Does anyone have an idea what the lower electrical KW would be?

You could check the compressor performance chart. Find your conditions and get a reading.

[heatingman]

cooler is small, the cost payback period would be forever.

Everything comes down to economics of scale.

The bigger the equipment, the more sense it makes to do things like your talking about.

If you have a whole lot of equipment and want to run a centralized tower setup, that makes some sense.

But, regardless more stuff means more stuff to fail. I like to keep things as simple as possible. You'd be better of increasing the size of the condenser and keeping it dx with a more efficient fan.

[basprofessional]

Yea it's only about 50 tons total compressor capacity. Irregarless, the system needs more condenser because the old one is under sized. I figured water would be the way to go.

[icemeister]

I'm not real savvy when it comes to cooling towers, but with a nominal 50 ton load, your tower flow rate would be about 150 gal/min based on 3 gal/min-ton. At standard conditions of 95ºF entering, 85ºF leaving and a 78ºF wet bulb temperature it would appear the evaporation rate would be around 1.5 gal/min.

Adding to that allowance for drift and bleed, your total water usage could be between 2-3 gal/min...or akin to an open spigot.

You may want to check into local regulations before going much further.

Here's a handy online calculator:

http://spxcooling.com/en/green/leed/...ge-calculator/

[craig1]

Don't forget the significant amount of maintenance required with cooling towers.

for only 50 tons, I suspect the water and maintenance costs will far outweigh the electricity savings.

[seemungaln]

well bor towers cost will be higher because of treatment to water system and if yo do the math between air and water which one work out for the customer from my point i like water as the source of heat tranfer but depents on load factor air might be the way to go for fifty tons