/ Field knowledge · IMC 605
Filter it before it hits the coil.
IMC 605: return, outdoor, and makeup air must be filtered upstream of the coil or heat exchanger. OA tied in downstream of the filter is the comment.
Educational 2024 IMC 605. Confirm adopted edition. This is not a MERV selection.
- Approved filters. Convenient approved location. Liquid adhesive coatings: flash point at least 325°F.
- Media-type: listed/labeled, UL 900. HEPA: UL 586. Electrostatic: UL 867. Dwelling-unit filters: designed for the application; listing/labeling not required by 605.2.
- Ducts constructed so airflow is even across the full filter face — not slammed on one side.
Higher MERV after bid
A higher MERV than designed raises pressure drop, cuts airflow, and can starve outdoor air. Substitutions need a fan recheck at dirty-filter resistance — the same check used on Masterbuild ESP summaries.
Source: DCT 605 · ESP: calculation support · 608: balancing.
What to send
The AHU/RTU schedule, where OA enters, and the filter type if specified.
If outdoor air joins after the filter
Send the unit section. Masterbuild will say whether 605.1 is even on the path — or the filter access only works on paper.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
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