Performance is our passion

PAG. 2FREE COOLING

TMA FC (190-1.200 kW)

GHA FC (68-1.700 kW)

VHA FC (18-1.163 kW)

Air cooled chiller with centrifugal compressors, axial fans and Free Cooling for outdoor installation.

Air cooled chiller with screw compressors, axial fans and Free Cooling for outdoor installation.

Air cooled chiller with scroll or reciprocating compressors, axial fans and Free Cooling for outdoor installation.

Turbomiser™

G

V

PAG. 3FREE COOLING

The operation of the free cooling system consists of finned pack heat exchangers placed in front of the condensing coils. The air crosses the water coils before hitting the refrigeration condensers of the re-frigerant.

When the outdoor temperature is lower than the returning water temperature the free cooling sys-tem can operate. The free cooling efficiency (EER) depends on the temperature difference between

the ambient and the desired chilled water temperature (EER is higher than the water/air delta tempera-ture increase).

The chiller can operate under three main conditions:• mechanical cooling• partial free cooling• total free cooling

Free Cooling Operation

PAG. 4FREE COOLING

Ambient temperature is higher than the re-turning water tem-perature. In this case the free cooling system is completely excluded and water cooling is obtained by compres-sor action only.

Ambient tempera-ture is lower than the returning water temperature (with a difference of at least 2-2.5 °C). In this case the water cooling depends on a combined action be-tween the free cool-ing operation and the working compressor. The system runs in this way when the water/air temperature differ-ence is not so high and the water coils cannot achieve the total re-quired cooling capac-ity.

Ambient temperature is lower than the re-turning water tem-perature. The water cooling and total cooling capacity depends on the free cooling operation only. The compressor ac-tion is completely ex-cluded. Normally, with standard applications, total free cooling can be achieved when the ambient is at least 6 °C lower than the desired chilled water tempera-ture.

Mechanical cooling

Partial free

cooling

total free

cooling

PAG. 5FREE COOLING

The abovementioned types of op-eration are automatically managed by a microprocessor control sys-tem designed to optimise energy consumption keeping to the pre-set working conditions.

The microprocessor receives four temperature inputs from sensors reading the fol-lowing parameters:• ambient tempera-

ture TAE• returning wa-

ter temperature from user’s plant TFC

• evaporator enter-ing water tempera-ture RWT

• evaporator leaving wa-ter temperature LWT

When the ambient air is at least 2 °C lower than the returning water temperature, the microprocessor allows the free cooling system to operate. Thanks to the three-way valve opening, water flows into

the water coils before crossing the evaporator.

Through the sensor monitoring the evaporator entering water temperature, the microprocessor accordingly reduces the compressor action (multistep capacity control)

until they are completely excluded if total free

cooling operation is reached.

If the free cooling efficiency is too high (as the ambient or

required cooling load is very low) to

keep a constant leaving water temperature, the

microprocessor proportionally reduces the air flow through the coils and if this is not sufficient, it controls the water flow in the coils by means of the three-way valve opening.

MicroprocessorControl System

PAG. 6FREE COOLING

Whenever it is required to maintain liquid even during the winter, Free Cooling chillers are the best choice.

The Free Cooling system works whenever ambient conditions are low enough to cool the chilled wa-ter without using refrigeration com-pressors. The system is especially effective when chilled water tem-peratures are relatively high.

These units are therefore indicated for conditioning systems for data processing centers, for the refrig-eration of industrial processing centers or of industrial processes.

The higher the difference of tem-perature between the circulating water and the outdoor air, the bet-ter the system will perform.

Superiorefficiency

35 °C

Chiller Mode

TFC -10 °C TAMB

EER

EER of FC units compared to standard units at the same conditions.

PAG. 7FREE COOLING

High qualitycomponents

FanS SeCtiOn

Finned PiPe COilS

HYdRaUliC CiRCUit

COntROl SYSteM

The main features of these fans adopted by Geoclima for the Turbomiser range of air cooled condensers are compactness, low noise level and exceptional efficiency. The variable speed drive fans react continuously to load variations ensuring maximum efficiency especially at partial loads. Compared to conventional fans energy savings of 30% can be achieved. Assuming continuous operation, the additional cost of these high efficiency fans is easily recovered within the first year.

Condenser coils made up of high-efficiency aluminium fins equipped with self-spacing clamps to guarantee not only perfect spacing (distance between fins) but also perfect contact with copper or stainless steel pipe (the latter on request), suitably spindled.FC coils made of copper pipes and aluminium fins. Support frame in aluminium or stainless steel, the supply collectors are equipped with air vent valves at the extremities and with water drainage valves in the lower part.

This includes the three-way proportional mixing valve for the insertion of the Free Cooling system, for constant water temperature control, and all the hydraulic connections between the evaporator and the finned exchangers. The entire unit is insulated with expanded rubber closed-cell type mattress, suitable for outdoor installation.

Regulation has been developed to respond to the most common requirements regarding the functioning of the chiller with Free Cooling during the winter. The software has been optimized to yield maximum results in terms of energy saving. The software controls the temperature of the water leaving the evaporator, interacting in an optimal manner between the 3-way valve, the fan speed regulator and the compressors.

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