HVAC Shop Blog

Matching the right Testo 420 flow hood to the outlet is the first step to a commissioning result you can sign off on. This guide covers all four hood sizes in the Testo 420 range, explains how to select the right option for square, linear and oversized outlets, and walks through flow straightener maintenance and storage. Practical advice for ARCtick-licensed HVAC-R techs, mechanical contractors, and anyone doing volume flow measurement on Australian commercial or residential sites.

The Testo 420 balometer is the go-to volume flow measurement tool for Australian TAB contractors. This guide covers multi-point measurement technique, swirl outlet correction, and app-based commissioning documentation across offices, hospitals, schools and data centres. Practical guidance for HVAC-R technicians and mechanical contractors working to Australian commissioning standards.