With more than 500 invited guests from across North America and Europe, Viessmann Manufacturing celebrated its silver anniversary in North America at the company's North American Headquarters in Waterloo, Ontario, Canada this past spring. The day-long event featured presentations by Dr. Martin Viessmann, CEO and owner of the Viessmann Group; keynote speaker Dr. David Suzuki, award-winning scientist, environmentalist and broadcaster; and Harold Prell, general manager of Viessmann North America.