Carbon and Water Footprint of Energy Saving Options for the Air Conditioning of Electric Cabins at Industrial Sites

Abstract

Modern electric and electronic equipment in energy-intensive industries, including electric steelmaking plants, are often housed in outdoor cabins. In a similar manner as data centres, such installations must be air conditioned to remove excess heat and to avoid damage to electric components. Cooling systems generally display a water–energy nexus behaviour, mainly depending on associated heat dissipation systems. Hence, it is desirable to identify configurations achieving both water and energy savings for such installations. This paper compares two alternative energy-saving configurations for air conditioning electric cabins at steelmaking sites—that is, an absorption cooling based system exploiting industrial waste heat, and an airside free-cooling-based system—against the traditional configuration. All systems were combined with either dry coolers or cooling towers for heat dissipation. We calculated water and carbon footprint indicators, primary energy demand and economic indicators by building a TRNSYS simulation model of the systems and applying it to 16 worldwide ASHRAE climate zones. In nearly all conditions, waste-heat recovery-based solutions were found to outperform both the baseline and the proposed free-cooling solution regarding energy demand and carbon footprint. When cooling towers were used, free cooling was a better option in terms water footprint in cold climates.

Influence of the Meteorological Record Length on the Generation of Representative Weather Files

“…The findings suggest that also other designing procedures of building systems could be influenced by these differences (considering also the extreme temperatures variations). Among the others, the systems whose efficiency depends on weather conditions should be studied, for example heat pumps [35][36][37], evaporative cooling systems [13,14] or dry coolers [15][16][17] systems, that are relevant for large scale planning, energy savings, water and carbon footprint reduction [38,39].…”

Utilising Cold Energy from Liquefied Natural Gas (LNG) to Reduce the Electricity Cost of Data Centres

“…In general, when considering tropical countries, such as Thailand, cooling systems consume more than 50% of the electricity consumption of data centres and result in an average PUE in Thailand of 2.0-2.5, representing almost double the electricity costs compared with cold countries with an average PUE of, for example, 1.15-1.40, as in Ireland. The current status of free and applicable cooling technologies consists of airside free cooling, waterside free cooling [5] and heat pipe technology.…”

“…IT devices cause huge heat release by transforming electrical energy into thermal energy. It is necessary that the temperature and humidity are controlled in data centres by using a cooling and air conditioning system to remove excess heat and to avoid damage to electrical components [5]. Refrigeration and air conditioning account for~50% of the total electric usage of a data centre [6][7][8].…”

“…The average PUE of data centres in Ireland, for example, is~1.15-1.40. The current status of free and applicable cooling technologies consists of airside free cooling, waterside free cooling [5] and heat pipe technology. Both airside free cooling and waterside free cooling can be integrated with other systems (e.g., absorption, solar systems, adsorption, evaporative cooling and geothermal for increased system performance [12]).…”