Fig. 2 Electric heater designed to inactivate airborne SARS-CoV-2 at
high temperatures as air passes through it. The electric heater consists
of a fan and stainless steel electric tube heating elements. The
electric heater’s fan draws outside air into the heater. The air heat
energy increases by interacting with stainless steel electric tube
heating elements perpendicularly to the airflow direction.
Two electric heaters were used to inactivate the airborne virus in the
30 m3 test room. The small electric heater had a power
of 1.5 kW, an airflow rate of 44 m3/hour, an air
travel time through the air tunnel of 0.97 seconds, and an outlet air
temperature of 220 oC. The large electric heater had a
power of 3 kW, an airflow rate of 324 m3/h, an air
travel time through the air tunnel of 0.03 seconds, and an outlet air
temperature of 150 oC. Air travel time through the
tunnel was measured as described elsewhere (Canpolat et al., 2022).