Spider is an aerobiological irradiation unit—or more simply an indoor air-processing device—that has eight or more small flexible ducts that create a web of recirculating air in any interior space. Indoor air everywhere can contain billions of microscopic bacterial, fungal, and viral pathogens that trigger asthma, infectious disease, and mold. Spider recirculates this air and in the process deactivates the pathogen’s DNA through a process known as photodimerization. This opens the existing DNA/RNA bonds and induces the formation of covalent linkages, by reactions, with neighboring molecules. This creates premutagenic lesions that alter the structure of the DNA and consequently arrest pathogenic replication and that leaves pure air in the space. The process continues 24/7/365.