I’m an air quality specialist who lives and breathes duct design and filtration upgrades — think MERV 13 retrofits and rebalancing to keep static under 0.8 in.w.c. — and I’m looking for shops that treat occupant health as a deliverable, not a tagline. Twin Cities area; any leads or firms scoping proper return paths and post-conversion airflow verification?
Find Twin Cities NEBB TAB firms; require ‘post-conversion airflow’ and ‘<=0.8 in.w.c.’ https://directory.nebb.org.
@matthew9418 makes a good point; my filter-first tell is asking bidders to include a ‘fan curve overlay with measured ESP and filter ΔP at MERV-13 load’ in the closeout — it instantly separates marketing from doers. Want intros to two MSP shops that hand this over?
Ask bidders to bake in a 2‑week controls trend pack — “ESP, filter ΔP, fan RPM, OA damper” — plus a door‑closed room pressure map proving return paths (≤3 Pa to corridor) so it’s not just vibes. Teams running ASHRAE Guideline 36 static reset usually get this right; quick sniff test is whether they show a pre‑bid point list and trend schedule: https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-addenda/guideline-36. Caveat: older RTUs may need an ECM kit or pulley change to hold 0.8 in.w.c. at MERV‑13 or your verification will fall on its face.