Installation of High‐Efficiency Air Filters
High‐efficiency air filters are normally installed only after the floor work is complete, ensuring that the cleanroom environment meets the strict requirements for filter installation. However, when using epoxy‐resin self‐leveling flooring, the work area cannot be ventilated during curing—posing serious health risks to the installers. In practice, workers often prop open doors or run blowers, but this compromises both the floor finish and the cleanliness of the room, making subsequent cleaning difficult.
To resolve this, the author recommends installing the high‐efficiency filters once the primer coat on the epoxy floor has cured. At that point the floor is already clean enough for filter installation. After the filters are in place, the second and top coats of epoxy can be applied under the operating clean‐air system, both ventilating the space and improving the working environment. Moreover, this airflow helps achieve an exceptionally smooth, dust‑free finish—often surpassing even automotive paint‐booth standards. This sequence preserves filter integrity, boosts floor quality, and protects workers’ health—truly a “three‐in‐one” solution worth adopting.
Pre‑Installation Preparations
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Complete All Interior Finishes
Before installing high‑efficiency filters, finish all cleanroom construction, millwork, and fixture installation. Thoroughly sweep and wipe down every surface. -
Commission the Clean‑Air System (“Air‑Blow”)
Run the air‑handling system empty for 12–24 hours. After the initial “air‑blow,” re‑clean the room—walls, ceiling, and floor—with technicians in clean attire. This flushes out most loose dust before filter installation. -
Final Cleaning
Once the primer coating on the floor is dry, remove any protective film from the filter plenum. Run the system empty for 30 minutes to purge airborne dust; then switch off, peel away wall‑panel films (trapping adhered dust), and clean again. Finally, run the system empty for another 12 hours (12 hours is sufficient—longer runs do not significantly reduce settled dust). Conclude with a last wipe‑down of all surfaces.
Step‑by‑Step Filter Installation
Team Organization
Install in crews of six: two unpack boxes and apply gasket tape, and four handle filter placement in two pairs.
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Gasket Tape Preparation
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Use 20–25 mm‑wide closed‑cell sponge or neoprene rubber tape, 6–8 mm thick.
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Cut and splice corners with a trapezoidal or interlocking joint (not butt joints).
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A corner‐cutting jig ensures neat, leak‑proof seams.
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Supervise and inspect all tape work before proceeding.
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Positioning the Filter
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Place the filter face‑up on a clean, level surface.
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If stacking filters, insert sturdy divider boards between them to avoid crushing the gaskets.
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Wipe the plenum interior and filter flange clean just before mounting.
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Sealing and Insertion
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Apply a bead of silicone sealant at each of the four gasket seams for added insurance against leaks.
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Working from opposite sides of a stepladder, gently slide the filter flush into the plenum opening.
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Securing the Filter
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Attach the four retention clips—or “pressure plates”—at the corners.
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Install clips diagonally opposite each other without fully tightening.
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Once all four are in place, adjust the filter so that the gap to the frame is uniform all around.
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Then, tighten each clip nut evenly, applying consistent pressure at all four points. Uneven tightening can warp the frame or compromise the seal.
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Diffuser Disc Installation
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If leak‐testing is required, perform it now before mounting the diffuser.
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Otherwise, position the diffuser panel over the filter face, aligning it carefully.
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Tighten bolts moderately to maintain uniform spacing.
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Before installation, wash each diffuser with detergent and water (or deionized water if available), then rinse and wipe dry in a clean area.
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Key Recommendations
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System Cleanliness: Most dust resides on duct interiors; the best way to keep ducts clean is to remove mill scale, welding slag, and oil before installation. Empty‑run flushing (“air‐blow”) removes only loose particles.
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Dynamic Process Control: Inspect and approve each step—tape fitting, filter seating, clip torque—to avoid time‑consuming leak hunts and rework later.
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Frame Choice: In biological cleanrooms, metal‐frame filters (galvanized or aluminum) are preferred over wood frames. For high‐capacity pleated filters, galvanized steel frames resist deformation better during clamping.
By following this optimized sequence—primer first, filter next, final floor coats under clean airflow—you safeguard filter performance, deliver a superior floor finish, and maintain a healthy work environment.
