Retrotec Comparison between Duct Blaster and Retrotec DucTester 341 - Manual

SP803 Page 1 of 5 rev-2014-09-14
Residential duct tester comparison:
The Energy Conservatory’s
Minneapolis Duct Blaster ® Series B
Released in 1992 the Duct Blaster has sold in
large numbers. Amazingly, it is still being sold
today, virtually unchanged.
Retrotec’s
Model 341 DucTester
Launched in 2014, this is the third iteration of
their DucTester.
Sports style bag holds all the parts as does the Retrotec custom case that has a stiff lid to act as a
gauge stand and an exterior vented pocket to keep corrosive smoke from destroying your gauge.
Duct tester performance and application
Duct testing standards for new houses typically limit the maximum acceptable leakage to 80 to
150 CFM whereas existing houses can have leakage up to an astonishing 300 CFM and still pass
Code requirements. Leakage above 500 CFM is difficult to measure because the air-handler’s
blower wheel would then represent a significant resistance and obscure leakage on the supply
side. Both duct testing systems will measure leakage well above these maximum leakages. Both
systems have about the same flow rate when depressurizing ducts which is the easiest direction
to test in because the negative pressure pulls the sealing tape onto the registers.