Chillers with free-cooling function from the GEA GLFC – DA2 range achieve EER values over 3.2 in cooling operation – thanks to their patented sub-cooler circuits
2014/02/03 In the cooling-duty range between 300 and 1,330 kW, the new air-cooled chillers from the GEA GLFC – DA2 range, with free-cooling function, are now available.GEA Heat Exchangers has increased the energy efficiency of these models by an average of 20 % over their predecessors.This improvement is primarily the result of their patented, integrated sub-cooler circuits.
Depending on the model, an EER greater than 3.2 is achieved: for 15/10 °C return/supply temperatures, 30 % ethylene glycol, and 35 °C air-intake temperature.In comparison to the predecessor range, the maximum unit output possible in free-cooling mode is consistently achieved at outdoor temperatures around 2 °C. These chillers are outstandingly well suited for facilities that must also be cooled while outdoor temperatures are low: e.g., for computer centers, telephone exchanges, production facilities, and buildings with a large share of glazed façades.For employment in IT and telecommunications facilities, a model with a maximum media outlet temperature of 20 °C can be selected (default version:15 °C).Also optional is an extended employment range for air-intake temperatures: down to -25 °C or up to 50 °C (default:-15 °C and 46 °C).
Like their predecessor range, the new chillers for outdoor employment have two refrigerant circuits (with R-134a as refrigerant) and screw compressors with continuously variable control.Shorter piping lengths as well as lower pressure drops in the evaporator contribute to greater energy efficiency.As options, EC fans are available, as is a noise-optimized SL version.In the standard version, 17 model sizes can be supplied, and the SL version is possible with 16 output ratings.A master-slave control system makes redundant and efficient operation possible.Integration into the higher-level building-services management system can likewise be implemented without difficulty.
The free-cooling function enables significant savings, since – for the GEA GLFC – DA2 range – this function already goes into operation when the outside-air temperature falls by 2 K below the return-flow temperature of the medium.Under these conditions, the integrated free-cooling heat exchanger cools the water to the greatest possible extent, and power consumption of the compressors falls appreciably.With low outdoor temperatures, it is even possible to dispense with operation of the compressor entirely.Reduced operating hours of the compressor lower energy consumption and CO2 emission – and extend maintenance intervals.
Owing to its reduced operating expenses, the added investment cost for a model in the GEA GLFC – DA2 range with free cooling, in comparison to the costs of a GLAC – CA2 (without free-cooling function), can be amortized within only a few months: depending on application circumstances and geographical region.