How Our Integrated
Chiller Economizer Works: 

When chiller cooling is needed, the onboard Economizer Controller begins
to check outdoor air temperature on approximately ten second intervals.
If the outdoor air temperature is approximately five degrees (F) cooler than
process fluid temperature, the Economizer Controller will be automatically
switching between four economizer states:

Mechanical Cooling State:  Outdoor air temperature has risen above
the Economizer deployment threshold temperature. While in this operating
condition, the Economizer Controller will stop process fluid flow to the
fluid (or dry) cooler and turn off it outside air circulation fan(s).

Combination State:  Outdoor air temperature remains below the Economizer
deployment threshold.  While in this operating condition, the Economizer
Controller will direct process fluid to a remote mounted fluid (or dry) cooler.
At the same time, fluid (or dry) cooler fan(s) will be turned on. During the call cycle,
the Economizer Controller will attempt to maintain desired process cooling setpoint
using the economizer as much as possible saving additional KWH.

Economizer Cooling State:  Outdoor air temperature remains below the Economizer deployment threshold. Process load and outdoor temperature conditions exists making it possible for the Economizer to maintain the process cooling setpoint. While in this operational state the Economizer Controller will lockout mechanical cooling creating significant KWH reductions.

Chiller De-ice State:  When outdoor air temperature remains below the Economizer deployment threshold for prolong periods of time, by design the mechanical cooling system will be deployed less.  This can create opportunities for ice and snow to build up within condenser fans causing damage to air-cooled condenser fans. To address this potential problem, the Economizer Controller allow mechanical cooling to run on specially programmed intervals preventing damaging ice buildup.

Alarm State:  In the event of a mechanical cooling system failure, the process fluid temp will begin to rinse. Once the process fluid increases to a point where Economizer cooling can be used, the Economizer controller will automatically start taking over full cooling until mechanical cooling can be repaired.

Call Us Today!  We would be Happy to further explain the Advantages
and Cost Savings of  the Legacy Economizer System
Energy Savings
Technology for 
Process Chillers
in Colder Regions
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Why Apply Economizers to Chillers? 

The For many years, fluid chillers have been used for a variety of specialty process applications such as
MRI, Lasers, Semiconductors, Fermentation control and even Advanced Military Application deployments.
On the climate control side, chillers are commonly used for other Mission Critical applications such as Surgical Centers, Network Data Centers and 911 Dispatch Centers. Compared to standard direct expansion (DX), cooling system chillers can offer enhancements in overall system efficiency while offering very tight temperature control.

Running parallel to popular Air-Side Economizers used in commercial air-conditioning, there is an new emerging market for chiller based (or Wet Side) Economizers. Until recently, deployment of chiller Economizers have been limited to larger tonnage (150 tons and up) applications mainly due to cost of control and maintenance of such systems. In early 2004, Legacy Chiller Systems took a close look at the subject of chiller based Economizers. We found there was a market for deployment of Economizer technology on small to medium size chiller applications. After three years of product development, Legacy was successfully awarded a US Patent for process chiller based Economizer System.

For More Information... Call Us Toll-Free at:  877-988-5464.