Executive Summary

The Testo 420 Flow Hood Balometer solves a major challenge in commercial HVAC air balancing.

Modern swirl diffusers create rotating air turbulence.

This turbulence causes traditional capture hoods to miscalculate airflow by up to 30%.

Testo built a patented volume flow straightener directly into the hood base.

They also reduced the total instrument weight to 6.2 lbs.

This design delivers lab grade volumetric flow accuracy.

It also reduces technician shoulder fatigue during long balancing projects.