In the early ’90s, Frank Hammes, Klaus' oldest son, joined the family business. After promoting an after-market cabin air filter the company had developed for Mercedes-Benz automobiles, Frank Hammes turned his attention to portable room air cleaners. Dissatisfied with existing products, he set out to build a line of portable air purifiers with medical grade air cleaning performance.
Frank Hammes and a small team of Swiss and German engineers worked for four years on the project. In the spring of 1998, IQAir shipped its first HealthPro air purifier from its Swiss factory. IQAir air purifiers were initially available only in Europe and Asia, but became available in the United States in 2000. In 2001, Klaus Hammes' second son, Jens Hammes, joined the business and helped the expansion of IQAir in Asia and the Middle East.