The present invention discloses an assembly of botanical biofiltration and evaporative cooling for improving an indoor Environmental Sciences quality to occupants of a space. The assembly comprises a receptacle with a cavity and a water reservoir, an evaporative cooling member comprising a mechanical fan and an evaporative corrugated plate for entraping dust particles and removes odors from the said stream of air, a botanical biofiltration member comprising growth media comprising biologically-active fibers mounted on the receptacle for container-grown plants to degrade and reduce air contaminants diffused in the said biologically-active fibers as the said stream of air passes through, and a water circulation member comprising a water pump for circulating water from the said water reservoir to the said evaporative corrugated plate and the said growth media.