Where Are Salt-Resistant Aluminum Separator Filters Suitable? An Air Intake Selection Guide for Coastal Industrial Facilities

Coastal factories, buildings, and power facilities need a continuous supply of outdoor air. However, incoming air may also carry airborne sea salt particles. When salt particles and humid air enter an air handling unit (AHU) or process air intake system, engineers must manage more than dust accumulation on filters. They must also consider the cleaning and maintenance of surrounding filter components, housings, and downstream equipment. This is why conventional medium-efficiency filters and salt-resistant filtration solutions should be evaluated separately.

Where are salt-resistant aluminum separator filters suitable? They are suitable for air intake systems in coastal factories, buildings, and other facilities that need to handle outdoor air containing sea salt particles. When selecting a filter, first assess the air intake location, site humidity, target particles, airflow, and equipment dimensions. Then evaluate the filtration efficiency, frame construction, and sealing method. Salt-resistant filters can be part of an overall air intake management strategy, but a single filter cannot guarantee that the entire system will be protected from corrosion.

Table of Contents

• Why Do Coastal Air Intake Systems Require Special Evaluation?
• Structure and Applications of Hencolin Salt-Resistant Aluminum Separator Filters
• Which Equipment and Locations Should Be Prioritized for Evaluation?
• Outdoor Air Handling Sections in Coastal Factories and Buildings
• Air Intake Systems That Require Downstream Equipment Protection
• Five Key Items to Verify When Requesting a Quotation
• Does “High-Humidity Resistance” Mean the Filter Can Remain Wet for Long Periods?
• Coastal Air Intake Selection: Start with Accurate Site Information
• Frequently Asked Questions (FAQ)
  • Can Salt-Resistant Aluminum Separator Filters Be Installed Directly Outdoors?
  • Will Installing a Salt-Resistant Filter Prevent Corrosion in an AHU?
  • Does the MERV Rating Indicate Sea Salt Removal Efficiency?
  • How Often Should the Filter Be Replaced?

Why Do Coastal Air Intake Systems Require Special Evaluation?

Airborne salt particles can enter air intake openings with sea breezes. Rainfall, changes in relative humidity, and equipment operating conditions can also affect the environment in which the filter operates. If cold surfaces cause condensation, water accumulates, or air leaks around the filter, contaminants may bypass the filter even when the selected media is suitable for capturing salt particles. The interior of the housing may also remain persistently damp.

Therefore, filter selection should begin with an assessment of the entire air intake path rather than relying solely on the filter’s product description.

The international standard ISO 29461-4:2025 addresses air intake filtration systems for rotating machinery in coastal and offshore environments. It establishes evaluation methods that consider salt particles and varying humidity conditions. Its scope covers specific air intake systems, so it should not be assumed that every filter labeled “salt-resistant” has been tested in accordance with this standard. Nevertheless, its testing approach highlights the importance of considering salt particles and humidity together.

Structure and Applications of Hencolin Salt-Resistant Aluminum Separator Filters

Hencolin salt-resistant aluminum separator filters use hydrophobic superfine glass fiber filter media, with corrugated aluminum separators to maintain spacing between pleats.

According to the manufacturer’s product information, applications include factories and buildings in coastal areas, as well as nuclear power plants. The product is positioned as a medium-efficiency filter designed to capture airborne sea salt particles.

It is not intended to treat salt dissolved in water or seawater, nor is it a chemical filter designed to remove gaseous contaminants.

The official product page lists multiple filtration grades and configurations, including box-type and flange-type designs. The frame material options are not presented consistently across all sections of the product page. Therefore, the available frame materials, dimensions, and mounting methods should be confirmed against the specific model and drawings provided during quotation.

If the existing filter rack requires a particular flange, gasket, or clamping arrangement, provide photographs and measurements before placing an order.

Which Equipment and Locations Should Be Prioritized for Evaluation?

Outdoor Air Handling Sections in Coastal Factories and Buildings

For make-up air units (MAUs), AHUs, or general outdoor air handling units located near the coast, salt-resistant medium-efficiency filters may be worth evaluating when downstream heat exchangers, air ducts, or process areas are sensitive to salt particles.

The intake louvers, rain protection, drainage, and upstream coarse filtration should also be inspected to prevent water droplets and large particles from directly impacting the medium-efficiency filter.

Air Intake Systems That Require Downstream Equipment Protection

If the downstream system contains high-efficiency filters, heat exchangers, or other equipment sensitive to particle deposition, the medium-efficiency filtration stage can capture a portion of the incoming particulate matter.

However, the need for multiple filtration stages depends on equipment requirements, the incoming contaminant load, and the available fan static pressure. A facility should not automatically be assigned the same filter grade or number of filters simply because it is located near the coast.

Five Key Items to Verify When Requesting a Quotation

1. Air intake conditions

Provide the air intake location, a description of the site’s proximity to the coast, records of rainwater ingress or condensation, and information about the cleanliness of the equipment interior.

2. Airflow and pressure drop

Provide the design and measured airflow rates, the differential pressure across the existing filter, and the available fan static pressure. When comparing specifications, ensure that the filters being compared have the same dimensions and are evaluated at the same airflow rate.

3. Dimensions and frame construction

Measure the actual filter rack opening, available installation depth, mounting method, and airflow direction. Confirm whether a box-type or flange-type configuration is required.

4. Filtration grade and downstream requirements

Describe the particle-related risks that must be controlled to protect downstream equipment. Any legacy EN 779 classifications or MERV ratings listed on the product page should be verified against the documentation for the specific model. They should not be treated as direct indicators of sea salt removal efficiency.

5. Maintenance criteria

Record the initial pressure drop of the new filter and establish inspection intervals. Include checks of housing drainage and perimeter seals in the maintenance plan. Replacement timing should be determined according to actual site conditions and equipment requirements.

Does “High-Humidity Resistance” Mean the Filter Can Remain Wet for Long Periods?

No. A product specification indicating humidity resistance may help determine whether a filter is suitable for a high-humidity environment. However, it does not mean that the filter or air handling unit can tolerate prolonged immersion, persistent condensation, or inadequate drainage.

If water droplets, standing water, or salt deposits continue to appear on-site, investigate the causes of inadequate rain protection, condensation, or drainage before selecting a replacement filter.

During maintenance, also check whether the filter is loose, damaged, or allowing air to bypass its edges.

Hencolin’s product page specifies a recommended final pressure drop. In practice, this value should be considered alongside the design airflow, measured differential pressure, filter media condition, and downstream equipment requirements when establishing inspection and replacement procedures.

Any indicative replacement interval mentioned on the product page should not be treated as a guaranteed service life for every coastal application.

Coastal Air Intake Selection: Start with Accurate Site Information

If your factory or building is experiencing salt accumulation in the air intake section, filter moisture problems, or a need for better downstream equipment protection, provide Hencolin with photographs of the air intake, filter rack dimensions, airflow rate, temperature and humidity data, and maintenance records.

These details will help Hencolin assess the appropriate filtration grade and frame configuration for its salt-resistant aluminum separator filters.

Selecting a filter based on actual air intake conditions provides a more reliable basis for decision-making than choosing specifications solely because a facility is located near the coast.

Frequently Asked Questions (FAQ)

Can Salt-Resistant Aluminum Separator Filters Be Installed Directly Outdoors?

Installation suitability should be confirmed according to the design of the filter mounting section. First, inspect the intake louvers, rain protection, drainage, and filter rack conditions. The filter itself should not be treated as a rain shield.

Will Installing a Salt-Resistant Filter Prevent Corrosion in an AHU?

No guarantee can be made. The filter primarily captures particulate matter in the air passing through it. Housing materials, protective coatings, standing water, air leakage, cleaning, and maintenance all continue to affect the condition of the equipment.

Does the MERV Rating Indicate Sea Salt Removal Efficiency?

No. MERV reflects particle filtration performance under a specified test method. It cannot be directly interpreted as a fixed removal efficiency for airborne sea salt particles under actual operating conditions.

How Often Should the Filter Be Replaced?

Replacement should be determined by the incoming contaminant load, airflow, pressure drop, and filter media condition.

Record the baseline pressure drop of a new filter, conduct regular inspections, and establish replacement criteria based on equipment requirements and the supplier’s recommendations.