Energy and economic assessment of major free cooling retrofits for data centers in Turkey

Abstract

Mechanical cooling is responsible for a significant fraction of the energy consumption of data centers (DCs).Free cooling systems take advantage of ambient conditions to reduce the need for compressor-based cooling. This studyutilizes thermodynamic models of major free cooling systems such as the direct air-side economizer (ASE), indirectair-side economizer (IASE), indirect evaporative cooler (IEC), and indirect water-side economizer (WSE) integratedwith the existing cooling infrastructure of a typical 1 MW IT load DC. Proposed models utilize hourly weather data ofvarious cities in Turkey to compute annual energy consumption and cost-saving potentials of each free cooling methodwith respect to the baseline DC with both open aisle (OA) and enclosed aisle (EA). Results confirm the energy-savingpotential by IEC leading to less than 10% of annual chiller hours across Turkey and less than 1% in half of the tencities studied, especially in EA DCs. However, despite greater energy-saving potential, IEC has more extended paybackperiods of 1.5 to 3.7 years due to the high capital investment compared with those of ASE and WSE with less than 1.4years.