Ekonomizer

Ekonomizer is a device used to recover energy from exhaust or waste streams to improve energy efficiency in heating, ventilation, and air conditioning (HVAC) systems, as well as in boilers and power generation. In HVAC, an air-side economizer uses outdoor air to assist in cooling when outdoor conditions are favorable. It employs dampers to modulate the mix of outdoor and return air and is controlled by sensors such as dry-bulb, wet-bulb, or enthalpy sensors. Benefits include reduced mechanical cooling loads, energy savings, and potentially lower peak electricity use. Limitations include maintaining acceptable indoor air quality, humidity control, potential ingress of outdoor pollutants, and the need for regular filtration and maintenance.

In boiler and power generation, an economizer is a heat exchanger placed in the flue gas path to recover heat from exhaust and preheat the feedwater entering the boiler, thereby increasing overall thermal efficiency. These economizers range from simple tube bundles to more complex finned designs and operate in corrosive, high-temperature environments where maintenance and material selection are important. The efficiency gain depends on operating conditions and can amount to several percentage points, influencing fuel use and emissions.

Modern systems may combine economizers with other energy-saving strategies, such as demand-controlled ventilation or variable air-volume control, in order to optimize performance. Design and operation require attention to moisture and corrosion management, air quality, control strategies, and compliance with relevant building and industry codes.

The term ekonomizer is used in several languages as a cognate of economizer, reflecting its purpose of saving energy, and encompasses both air-side and heat-recovery variants in industrial and building services contexts.