A: Frequency varies with filter type, the location of your unit as well as other environmental factors. A high temperature air filter has a lifespan that can range from 6 months to 1 year. In addition, the industry you work in also affects the frequency of change outs that are required. For example, restaurants might change an industrial air filter every 4 to 8 weeks. Retail stores might change every 12 weeks, so it all depends on factors that are prominent in your environment including smoke, soot and other airborne contaminants.