impingement filter

Impingement Filter

This page lists all 106 Impingement Filter replacement filters available from Metal Air Filters — precision-manufactured washable aluminum mesh filters engineered as direct OEM replacements for Carrier commercial HVAC equipment. All filters on this page are HI Series products manufactured by American Metal Filter Company (AMFCO) with .030" extruded aluminum alloy frames, corrugated aluminum mesh media, UL 900 Class 1 certification, and a 275°F maximum operating temperature rating.

Each filter is a permanent washable replacement — clean and reuse for 5–10 years rather than replacing disposable filters every 30–90 days. AMFCO’s aluminum mesh construction provides 43% average dust arrestance per ASHRAE 52.1, making these filters ideal pre-filters in multi-stage Carrier commercial HVAC systems protecting downstream MERV 8 through HEPA filtration stages in rooftop units, air handlers, and split systems.

Commercial & Industrial Applications

Carrier commercial HVAC equipment is deployed across a wide range of commercial, institutional, and industrial building types. The following applications represent the primary use cases for Impingement Filter permanent washable aluminum mesh filters.

The HMA102025 20x25x1 aluminum mist eliminator filter delivers reliable performance across commercial, institutional, and light industrial environments where airborne moisture, water droplets, oil mist, or coolant mist must be separated from the airstream to protect downstream HVAC equipment, prevent corrosion and biological growth, and maintain system performance. The impingement-type aluminum screen wire construction, 275°F temperature rating, and all-aluminum corrosion resistance make this filter suitable for continuous operation in demanding applications that would degrade or destroy lower-rated filter alternatives.

Outside Air Intakes and Ventilation Systems

Commercial and institutional buildings’ outside air intake systems subject HVAC equipment to rain entrainment, wind-driven water, morning dew, and seasonal precipitation that introduce liquid water into ductwork and air handling equipment. The HMA102025 installed at outside air intake locations captures water droplets before they reach fan sections, coils, controls, and downstream filter banks, preventing moisture accumulation that causes rust, corrosion, biological growth, and equipment failure. Commercial office buildings, hospitals, schools, and institutional facilities with outside air systems in coastal, humid, or precipitation-prone climates benefit from the HMA102025’s 99%+ capture efficiency on 3-micron and larger water droplets, combined with the passive gravity drainage system that continuously removes captured moisture during normal HVAC operation without operator intervention. Building engineers specifying outdoor air system protection rely on the HM Series mist eliminator’s long service history and verifiable test data to meet ventilation system performance requirements and equipment warranty conditions.

Chilled Water Coil Protection

Chilled water coil sections in commercial air handling units generate condensate during normal cooling operation, and coil surfaces can become sites for airborne moisture accumulation that migrates downstream when airflow velocity exceeds the coil’s carry-over limit. Installing the HMA102025 downstream of chilled water coil sections captures carried-over moisture droplets before they reach supply ductwork, fan sections, and terminal equipment, protecting investments in downstream components and preventing moisture-related indoor air quality problems. Data centers, server rooms, precision manufacturing facilities, healthcare environments, and other applications with strict humidity control requirements benefit from the HMA102025’s combination of high-efficiency moisture capture and heavy-duty washable particulate filtration in a single permanent panel filter unit that installs in standard 20x25x1 nominal side-access or built-up filter bank positions.

Mist-Type Humidifier Applications

Steam and evaporative humidifier systems introduce moisture into airstreams to maintain required relative humidity levels in commercial buildings, data centers, healthcare facilities, museums, and manufacturing environments where humidity control is critical for occupant comfort, process control, or material preservation. Improperly positioned or oversized humidifiers can introduce unevaporated water droplets into ductwork that cause corrosion, biological growth, and moisture damage to insulation and finishes downstream. Installing the HMA102025 downstream of mist-type humidifier discharge points captures unevaporated droplets before they enter distribution ductwork, providing a reliable safeguard against water damage from humidifier over-injection events while also providing heavy-duty particulate filtration of the humidified supply air stream.

Industrial and Coolant Mist Applications

Light industrial manufacturing operations using coolant mist delivery systems, metalworking equipment, or process cooling generate oil mist and coolant aerosols that must be captured before entering building HVAC systems or exhausting to outside air. The HMA102025’s impingement-type aluminum screen wire construction captures oil mist and coolant aerosol droplets through the same mechanism it uses for water droplets, collecting the captured liquid in the frame and draining it by gravity when installed upright. Industrial ventilation engineers specifying mist control for machining centers, stamping operations, and cooling tower exhaust applications select the HM Series aluminum mist eliminator for its 275°F temperature rating, all-aluminum construction compatible with coolant chemistry, and heavy-duty washable mist eliminator filter design that withstands the frequent and rigorous cleaning demanded by industrial operating environments. The HMA102025 handles the demanding conditions of industrial mist control applications that would rapidly degrade electrostatic, pleated, or cardboard-framed filter alternatives.

Frequently Asked Questions

How does the HMA102025 aluminum mist eliminator filter work?

The HMA102025 operates on the impingement principle: water droplets and oil mist cannot follow the tortuous path through the 9-ply aluminum screen wire media layers at 500 fpm and collide with wire surfaces where surface tension holds captured liquid until it drains through the 3/8″ bottom drain holes. Achieves 99%+ efficiency on 3-micron+ water droplets.

How do I clean the HMA102025?

Rinse with a moderate-to-heavy stream of warm water from the clean side through to the dirty side until water runs clear. High-powered steam cleaning and chemical dips are not recommended. Air dry or shake off excess water before reinstalling. Filter Coat adhesive may optionally be reapplied after each wash if adhesive treatment is used.

Why must the HMA102025 be installed with the TOP label facing upward?

The 3/8″ drain holes are along the bottom of the frame and only function when the filter is upright with TOP facing up. Installing sideways or inverted prevents captured moisture from draining, reducing separation efficiency and potentially causing liquid re-entrainment into the airstream.

What is the maximum operating temperature?

The HMA102025 HMA aluminum model is rated for 275°F continuous operation. For higher temperatures, AMFCO offers HMG galvanized (325°F) and HMS stainless steel (900°F) variants in the same HM Series.

What are the actual dimensions of the HMA102025?

Actual dimensions: 19.375″ H x 24.375″ W x 0.875″ D (±1/8″ H&W, ±1/16″ depth). Nominal size: 20x25x1. HM Series uses 5/8″ undercut on height and width—not 1/2″ as used by some other filter series.

Can I use Filter Coat adhesive on this mist eliminator filter?

Yes—the HM Series aluminum mist eliminator may optionally be sprayed with Filter Coat, a water-soluble adhesive and detergent, before installation to enhance particulate capture. Filter Coat washes off during routine cleaning and must be reapplied after each wash cycle if desired.

Are polyurethane gaskets available for this filter?

Yes—the HM Series may be supplied with polyurethane gaskets on the vertical sides of the frame for side-access housing applications requiring a moisture-tight seal. Specify ‘with gaskets’ and indicate which dimensions (short or long side) require gaskets when ordering.

How often should I wash this mist eliminator filter?

Wash frequency depends on application: outside air intakes in dusty environments typically every 1–3 months; commercial moisture separation applications every 3–6 months; industrial coolant mist applications may need monthly washing. Inspect visually and monitor drain hole flow as indicators for washing timing.

How does the HMA aluminum model compare to HMG and HMS models?

HMA (.030″ aluminum frame, 24 ga aluminum face grids): 275°F max, frequent and moderate washability. HMG (24 ga galvanized steel): 325°F max, frequent and rigorous washability. HMS (24 ga stainless steel, stainless screen wire): 900°F max. All use aluminum screen wire media except HMS. Contact Metal Air Filters for HMG or HMS if your application requires higher temperature ratings.

Is the HMA102025 compatible with my HVAC system?

The HMA102025 is designed for commercial and industrial HVAC systems operating at 500 fpm (450–550 fpm recommended range)—higher than standard residential airflow. It fits 20x25x1 nominal filter positions in outside air ducts, side-access housings, and built-up filter banks. Verify your system airflow is within range for optimal moisture separation performance.