air conditoning system

I need to know what the application is and more detail. The question is too broad to comment on.

I agree - significantly more information is needed to make a suggestion.

Most important are key items like:

-location of the unit (helps with ambient air temperature design points)

-size of the building

-use of the building

-nearby industrial facilities (can use waste heat from another unit?)

Also, see the ASHRAE handbook (http://www.ashrae.org/publications/page/158).

Stephan

Normally, water cooled systems are more efficient than air cooled. Water cooled uses the wet bulb tempeture of the air (~78 deg) to produce 85 degree water and send it to the chiller. The heat transfer between water and refrigerant is very good and the compressor does not have to work that hard. Air cooled uses (~95 deg) air for condensing and the heat transfer between air and refrigerant is not as good. Therefore the compressor has to work harder. Of course water cooled is more expensive (get what you pay for) due to the cost of the cooling tower, condenser piping and valves, condenser pumps, water treatment, maintenance ect. If you are running 24/7 then (GENERALLY) water cooled is very attractive. If you are running as an office (50 hours/week) and the utility rates are low, then (GENERALLY) air cooled might be the way to go. Normally we life cycle these systems and a lot of the determination of the systems is based on how expensive is electrical consumption (cents/kwh), electrical demand ($/kw) and time of day rates.

First define what is a package cooled water systems first time I hear from them... then I will address you on aproximate energy efficieny ratios for both systems

regards