Retrotec is the innovative leader in blower door manufacturing.  Retrotec has been manufacturing blower door and duct testing equipment since 1980, and sells into over 5o countries worldwide.  Retrotec is the only blower door manufacturer that produces a full line of equipment to meet virtually every air infiltration testing need.  We manufacture low flow fans suitable for testing very tight enclosures, residential fans suitable for testing average homes to approximately 5000 sq. ft., and portable high-power (2hp) systems suitable for testing extremely large or leaky homes, and multi-fan high power systems for testing commercial spaces.