I’m re-tooling my commissioning kit and want one portable instrument that balances accuracy and battery life for VAV airflow checks, so I’m not hauling the TSI hood on every floor. With a Testo 405i hot-wire plus a Dwyer 477 manometer and pitot I’m seeing about ±8% at about 1,200 CFM, which makes static reset and minimums harder to dial in without overventilating — what are you using that reliably nails VAVs for energy-focused tuning, and any specific models you trust?
I’ve landed on a Shortridge ADM-870 with the pitot — it keeps me in the 3–4% range on VAV inlets and a single 9V lasts a couple weeks. At “8% at about 1,200 CFM” you’re likely fighting swirl off the box, so do a quick 10-point traverse 3–5 duct diameters upstream and set a 5–10 s average; just don’t forget the inlet ring K-factor or it’ll chase the damper like a cat laser.
I moved to a TSI DP-Calc 5825 with a 166 pitot; with a 10‑point traverse and temp comp I stay about 3–4% on most VAV inlets, and it runs about 30–40 hours on AAs — way better than your “±8% at 1,200 CFM”. Small caveat: you need a clean run; if the inlet’s swirly I step 1–1.5D upstream or drop in a short straightener so I’m not chasing noise. Also saves me a backpack chiropractor visit.