Exhaust unit and image forming apparatus

An exhaust unit comprising:

• a photocatalyst filter laminate;
• a first light source to irradiate the photocatalyst filter laminate with light having a wavelength of 400 nm or more;
• and
• an exhaust fan to discharge gas from an exhaust port, wherein
• the photocatalyst filter laminate is disposed in the exhaust port;
• the photocatalyst filter laminate includes a first photocatalyst filter disposed at a surface receiving light from the first light source and a second photocatalyst filter disposed on a central portion of the photocatalyst filter laminate or at a surface opposite to the light-receiving surface;
• the first photocatalyst filter has an aperture percentage higher than an aperture percentage of the second photocatalyst filter;
• the first photocatalyst filter and the second photocatalyst filter are stacked;
• the photocatalyst filter laminate has a thickness of 1 mm or more and 10 mm or less;
• each of the first photocatalyst filter and the second photocatalyst filter includes a sheet-shaped filter substrate and a photocatalyst layer supported by the filter substrate,
• the filter substrate is a wire netting, a punching metal, an expand metal, a non-woven fabric, a fabric, a resin molding, or a paper honeycomb sheet;
• the photocatalyst layer exhibits a photocatalytic action by receiving the light having a wavelength of 400 nm or more;
• the aperture percentage of each of the first photocatalyst filter and the second photocatalyst filter is 35% or more and 80% or less;
• and
• the aperture percentage is a proportion of a through opening area per unit area of the photocatalyst filter.