Apparatus and installations for ventilating purposes, namely, ventilating fans for commercial and industrial use, ventilating louvers, direct vents for gas appliances, oven and stove ventilating hoods; air filtering installations, namely, industrial air filter machines, air filters for industrial installations, air cleaning units containing an air filter, ultraviolet lights and a photocatalytic filter; ventilation installations and apparatus, namely, ventilating fans for commercial and indust...