The quality of indoor air is of increasing concern because it is closely related to human health. An air handling unit (AHU) can be used to control the quality of indoor air with respect to particulate matter and CO2, as well as providing air conditioning by regulating the temperature and the humidity. Electrostatic precipitators have high collection efficiencies and low pressure drops. However, their chargers can generate ozone, which is a drawback of applying them to indoor air control. In this study, we compared four discharging electrodes: a 50-µm tungsten wire, a 100-µm tungsten wire, 16-µm aluminum (Al) foil, and carbon fabric composed of 5–10-µm fibers. The carbon-fabric electrode exhibited superior particle collection efficiency and lower ozone generation for a given power consumption compared to the 50- and 100-µm tungsten wires, or the Al foil electrode. This low-ozone-generating, micro-sized electrode can be applied as an electrostatic precipitator in AHUs for indoor air control.