Description

Product Overview

The HMAS20 is a custom make-to-order 2-Inch washable aluminum aluminum mist eliminator filter filter manufactured to your specified height and width dimensions. Engineered for permanent installation in HVAC systems, outside air ducts, side-access housings, and built-up filter banks where standard catalog sizes do not fit, the HMAS20 delivers the same HM Series impingement-type moisture separation and heavy-duty washable particulate filtration performance as catalog HMA products—built to the exact height and width you specify. As a custom order, the HMAS20 requires customer-provided dimensions at time of order; contact Metal Air Filters with your required height and width to request a quote and lead time.

Constructed with a precision-formed .030” thick aluminum frame, 24 gauge aluminum face grids on both the air entry and exit sides, and a 13-ply aluminum screen wire moisture separator wire media pack—multiple layers of corrugated and flat screen wire positioned for efficient drainage, placed between two layers of expanded metal—the HMAS20 delivers consistent moisture separation and particulate filtration performance with the structural durability required for demanding commercial and industrial HVAC applications. The nominal 2” depth produces an actual depth of 1-3/4″ per standard HM Series manufacturing convention. Height and width are fabricated to your specified dimensions with ±1/8” tolerance.

Unlike electrostatic or pleated media filters designed primarily for fine particulate capture, the HM Series aluminum mist eliminator filter operates on the impingement principle: water droplets and oil mist in the airstream cannot follow the tortuous path through the corrugated aluminum screen wire moisture separator wire layers at rated velocity, causing them to collide with the screen wire surfaces where surface tension holds the collected liquid. The captured liquid accumulates and drains by gravity through the 3/8” diameter drain holes along the bottom of the filter frame when installed in the correct upright orientation with the TOP label facing upward. This passive drainage mechanism requires no power, pumps, or active components—gravity moves collected moisture to the drain while the HVAC system operates normally. The 13-ply aluminum screen wire media pack provides the optimal combination of tortuous path length, surface area, and drainage channel geometry for efficient liquid separation at rated 500 fpm airflow.

The HMAS20 custom aluminum aluminum mist eliminator filter is manufactured by American Metal Filter Company (AMFCO) to the same construction standards as catalog HMA products. The all-aluminum construction—frame, face grids, and screen wire media—provides consistent corrosion resistance in moisture-laden applications where the filter is continuously exposed to water droplets and elevated humidity conditions. Pop-rivet corner construction and mitered joints maintain critical face dimensions within ±1/8” tolerance throughout the filter’s operational lifetime. Contact Metal Air Filters to place a custom order: provide your required height, width, and any special requirements such as polyurethane gaskets or Filter Coat treatment.

How to Order Your Custom 2-Inch Aluminum Mist Eliminator

The HMAS20 is a make-to-order product. Because height and width are built to your specifications, please contact Metal Air Filters before placing your order to confirm your required dimensions, lead time, and pricing. Having the following information ready will ensure a fast, accurate quote:

• Required Height: The actual height of the filter you need (in inches, to the nearest 1/8”). Note that HM Series depth uses a 7/8” (0.875”) actual 2-Inch convention—only height and width are customer-specified.
• Required Width: The actual width of the filter you need (in inches, to the nearest 1/8”).
• Quantity: The number of filters required. Custom orders may have minimum quantity requirements—confirm with Metal Air Filters.
• Gasket Option: Whether polyurethane gaskets on the vertical frame sides are required for your side-access housing application.
• Application: Brief description of your application (outside air intake, chilled water coil protection, industrial mist, etc.) to help confirm the right specification.

Once your order is confirmed and dimensions verified, production and shipping lead time will be quoted. Custom filters are built to order and cannot be returned or exchanged, so confirming your housing dimensions before ordering is essential. Contact Metal Air Filters by phone or email to place your custom HMAS20 order.

Commercial & Industrial Applications

The HMAS20 custom 2-Inch aluminum mist eliminator filter is specified for commercial, institutional, and industrial HVAC applications where standard catalog HMA filter sizes do not match the required housing dimensions. The make-to-order capability allows HVAC engineers, facilities managers, and building operators to specify precise filter dimensions for retrofit projects, non-standard ductwork, existing side-access housings with unusual dimensions, and built-up filter bank configurations requiring exact sizing for proper bypass prevention.

Non-Standard Housing Retrofit Applications

Existing commercial buildings often have HVAC systems installed with non-standard filter housing dimensions that do not match current catalog sizes. Outside air intake housings, side-access filter housings in older air handling units, and built-up filter banks assembled from site-specific ductwork frequently require custom filter dimensions that off-the-shelf products cannot satisfy. The HMAS20 custom aluminum mist eliminator provides the same HM Series impingement-type moisture separation performance in a filter built to the exact dimensions required for proper fitment in these non-standard housings, eliminating bypass gaps that reduce moisture capture efficiency and compromise downstream equipment protection.

Chilled Water Coil and Humidifier Protection

Data centers, server rooms, precision manufacturing facilities, healthcare environments, and other applications with strict humidity control requirements frequently have AHU configurations with non-standard filter section dimensions. The HMAS20 custom filter provides 99%+ moisture separation and water droplet separator efficiency in a 2-Inch impingement-type panel filter built to the exact AHU interior dimensions, capturing chilled water coil carry-over and humidifier droplets before they enter supply ductwork. Custom sizing ensures complete face coverage with no bypass gaps for critical moisture control applications where even small amounts of uncaptured moisture cause equipment damage, biological growth, or contamination.

Industrial and Coolant Mist Applications

Industrial ventilation systems handling coolant mist, metalworking aerosols, and process exhaust frequently use ductwork and housings fabricated to plant-specific dimensions that require custom filter sizing. The HMAS20’s 13-ply aluminum screen wire construction captures oil mist and coolant aerosol droplets through the same impingement mechanism used for water droplets, with the 275°F temperature rating and all-aluminum construction providing compatibility with common industrial coolant chemistry. Custom height and width allow precise fitment in industrial ductwork and exhaust housings without air bypass that would defeat mist capture performance.

Construction Features

The HMAS20 custom aluminum mist eliminator filter uses identical materials and construction methods as catalog HMA products, ensuring the same verified performance specifications are achieved in your custom-dimensioned filter. Every component—from the precision-mitered aluminum frame with drain holes to the 13-ply aluminum screen wire media pack and dual 24 gauge aluminum face grids—is specified for consistent impingement-type mist capture, structural durability, corrosion resistance, and complete washability.

Aluminum Frame with Gravity Drainage

The precision-formed .030” thick aluminum perimeter frame is fabricated to your specified height and width with ±1/8” dimensional tolerance, maintaining true 90-degree mitered corners secured with pop rivets. The all-aluminum construction eliminates the rusting and frame deterioration that affect galvanized or coated steel frames when continuously exposed to water droplets, coolant mist, and elevated humidity at temperatures up to 275°F. The 3/8” diameter drain holes positioned along the bottom of the frame provide the exit path for captured moisture—captured water droplets and oil mist flow downward through the screen wire media, collect at the frame bottom, and exit through the drain holes to an appropriate drain location when the filter is installed with the TOP label facing upward.

13-Ply Aluminum Screen Wire Media Pack

The 13-ply aluminum screen wire media pack is the performance core of the HMAS20, providing the tortuous impingement path geometry required for efficient water droplet and oil mist capture at rated 500 fpm airflow. Multiple layers of corrugated and flat screen wire alternated in a precise pattern create an extended series of direction changes that airborne water droplets cannot navigate at rated velocity—they collide with wire surfaces where surface tension holds the captured liquid until it accumulates enough to drain by gravity to the frame bottom and out through the drain holes. The entire media pack is placed between two layers of expanded metal that protect it from physical damage during installation, removal, and washing. The same 13-ply media construction used in catalog 2-Inch HMA filters is applied to your custom-dimensioned filter, delivering the verified 94.9% efficiency at 2.5–3 microns and 99.1% efficiency at 3–4 microns documented in the independent test report.

24 Gauge Aluminum Face Grids

24 gauge aluminum face grids on both the air entry and exit sides provide uniform airflow distribution across the filter face area while protecting the aluminum screen wire media pack from physical damage. The grids are fabricated to match your custom filter dimensions, ensuring complete face coverage and consistent face velocity distribution that maximizes impingement contact and capture efficiency. Aluminum construction matches the frame and media materials for consistent corrosion resistance through years of washing cycles and moisture-laden operating conditions.

Maintenance & Cleaning

The HMAS20 custom aluminum mist eliminator filter requires periodic washing to maintain optimal moisture separation performance and restore the 13-ply aluminum screen wire media pack’s capture efficiency. The washing process is identical to catalog HMA filter maintenance—requiring only access to warm running water—and the AMFCO tech sheet specifies “frequent and moderate” washability for the HMA aluminum model.

Washing Procedure

Remove the HMAS20 from the filter housing, noting the TOP label orientation. Rinse with a moderate-to-heavy stream of warm water from the clean side through to the dirty side until water runs completely clear. For filters in oil mist or coolant mist applications, a mild detergent solution may be used followed by a thorough fresh-water rinse. Do NOT use high-pressure washing equipment that could deform the corrugated screen wire layers. Allow the filter to air dry or shake off excess water before reinstalling. If Filter Coat adhesive treatment is used, reapply after each wash cycle per Filter Coat product instructions.

Washing Frequency Guidelines

Outside air intake applications in dusty environments typically require washing every 1–3 months. Chilled water coil and humidifier applications in commercial buildings typically require washing every 3–6 months. Industrial coolant mist applications may require monthly washing. Visual inspection and monitoring for reduced drainage through the drain holes are the most reliable indicators for washing timing. Systems with differential pressure monitoring can use filter pressure drop rise above baseline as an objective washing trigger.

Installation

Installing the HMAS20 custom aluminum mist eliminator requires one critical orientation step not required with standard particulate filters: the filter must be installed with the TOP label facing upward in all moisture separation applications to ensure captured liquid drains correctly through the bottom frame drain holes. Verify your housing interior dimensions accommodate the custom filter dimensions you ordered before installation.

Pre-Installation Checklist

• Confirm housing interior dimensions match the custom filter dimensions ordered (within ±1/8” tolerance on height and width)
• Confirm HVAC system operating temperature does not exceed 275°F at the filter location
• Identify the TOP label and confirm housing orientation allows it to face upward
• Locate drain holes along the bottom frame and confirm they drain to an appropriate collection point
• If gasket option was ordered, verify gaskets are properly positioned on vertical frame sides
• Clean housing interior of accumulated dust and debris

Installation Steps

Shut down the HVAC system. Remove any existing filter. Orient the HMAS20 with the TOP label facing upward. Insert the filter into the housing maintaining upright orientation throughout. Press firmly into place ensuring all four frame edges seat properly against housing walls. Secure with the housing retention mechanism. Verify drain holes are unobstructed and positioned to drain to an appropriate collection point. Restore power and restart the HVAC system. Record installation date and orientation. During the first operating period, check the drain area for moisture drainage to confirm correct positioning.

Frequently Asked Questions

What dimensions can I specify for the HMAS20?

Height and width can be specified to your exact requirements in 1/8” increments. The nominal depth is 2” (1-3/4″ actual depth per HM Series manufacturing convention). Contact Metal Air Filters with your required height and width to receive a quote and confirm lead time before placing your custom order.

How does the HMAS20 mist eliminator filter work?

The HMAS20 operates on the impingement principle: water droplets and oil mist cannot follow the tortuous path through the 13-ply corrugated aluminum screen wire layers at rated 500 fpm velocity and collide with wire surfaces. Surface tension holds the captured liquid on the wire until it accumulates and drains by gravity through the 3/8” drain holes along the bottom of the frame. This achieves 99%+ efficiency on 3-micron and larger water droplets without electricity, moving parts, or active components.

How do I clean and wash the HMAS20?

Remove the filter and rinse with a moderate-to-heavy stream of warm water from the clean side through to the dirty side until water runs completely clear. High-powered steam cleaning and chemical dips are not recommended. Shake off excess water and air dry or reinstall. If Filter Coat adhesive treatment is used, reapply after each wash cycle.

Why must the HMAS20 be installed with the TOP label facing upward?

The 3/8” drain holes are positioned 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 HMAS20 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 is the lead time for a custom HMAS20 order?

Lead time varies by dimensions and current production schedule. Contact Metal Air Filters with your required dimensions and quantity to receive a current lead time quote. Custom orders cannot be returned or exchanged once production has begun, so confirming housing dimensions before ordering is essential.

Are gaskets available for the HMAS20?

Yes—the HMAS20 may be supplied with polyurethane gaskets on the vertical sides of the frame for side-access housing applications. Specify the gasket option and indicate which sides (short or long) require gaskets when placing your order.

How often should I wash the HMAS20?

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. Visual inspection and monitoring drain hole flow are the most reliable washing indicators.

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 (galvanized steel): 325°F max, frequent and rigorous washability. HMS (stainless steel): 900°F max. All use aluminum screen wire media except HMS. Contact Metal Air Filters for HMG or HMS custom sizing if your application requires higher temperature ratings.

Why Choose the HMAS20 Custom Aluminum Mist Eliminator?

The HMAS20 custom HM Series aluminum mist eliminator filter solves the critical problem of non-standard housing sizes in commercial and industrial HVAC systems where catalog filter dimensions do not fit. With independently verified 99%+ water droplet capture efficiency on 3-micron and larger droplets, the HMAS20 provides reliable permanent moisture protection for chilled water coils, fan sections, ductwork, and building equipment—built to the exact height and width your housing requires. The passive gravity drainage system through the 3/8” bottom drain holes removes captured moisture continuously during normal HVAC operation, requiring only periodic washing to maintain peak performance.

Built with precision-formed .030” thick aluminum framing fabricated to your specified dimensions, 13-ply corrugated and flat aluminum screen wire media, and 24 gauge aluminum face grids on both sides, the HMAS20 combines structural durability with all-aluminum corrosion resistance essential for long-term moisture separation service. The straightforward warm-water washing procedure restores full moisture separation and particulate filtration performance without specialized tools or cleaning agents. Optional polyurethane gaskets for side-access housings provide installation flexibility for demanding applications. Made in USA by American Metal Filter Company to the same exacting standards as catalog HMA products.

Choosing the HMAS20 custom permanent washable aluminum mist eliminator eliminates recurring disposable filter replacement costs while providing a higher level of moisture protection than standard particulate filters. The combination of 99%+ water droplet efficiency, heavy-duty secondary particulate filtration, 275°F temperature capability, and decades-long all-aluminum durability makes this filter the engineering-sound choice for any commercial or industrial HVAC application requiring a custom-dimensioned impingement-type moisture separation solution. Contact Metal Air Filters to place your order: provide your required height, width, quantity, and any special requirements (gaskets, Filter Coat treatment).