The stakes are higher when designing HVAC and plumbing systems near the ocean. Salt-laden air, high humidity, and corrosive conditions can significantly reduce the lifespan and performance of mechanical equipment and fixtures. Whether you’re working on a marine research facility, a waterfront national park, or a retail store with water views, understanding how to protect your HVAC systems in these environments is essential.
Why Marine Environments Are So Challenging
Salt in the air accelerates corrosion, especially on exposed metal components like condenser coils, piping, and ductwork. Over time, this can lead to:
- Reduced heat transfer efficiency
- Increased maintenance costs
- Shortened equipment lifespan
- Equipment failure
HVAC Equipment Coil Protection
When you are near the ocean, protecting your condenser and/or evaporator coil is essential to ensuring the longevity of your equipment. Without this, corrosion can occur at your coils, reducing the equipment’s lifespan.
- Location Matters:
- Within 3–5 miles of the ocean: Your outdoor condenser coil should have a salt-spray rating that meets ASTM B117 standards.
- Within 1 mile of the ocean: Both the condenser and evaporator coils should have a salt-spray rating that meets ASTM B117 standards.
- This salt-spray coating can either be factory applied or applied by a third-party provider. This should be coordinated with the equipment manufacturer to ensure the final requirements can be reflected in your drawings.
Material Selection
Beyond coils, all exposed materials should be chosen for their resistance to corrosion:
- Piping: Use corrosion-resistant materials or coatings such as PVC or type 316 Stainless steel.
- Ductwork: Type 316 stainless steel may be necessary depending on the amount of exposure to salt-laden air.
- Outdoor Fixtures: Hose bibbs, wall hydrants, and other plumbing fixtures on the exterior of the building should be marine-grade.
- Drainage Systems: If saltwater is expected to enter drains (e.g., from rinsing equipment), ensure the drain materials are properly specified for this marine grade application.
- Confirm if sand will be a concern in the space and if sand interceptors should be considered on certain drain lines.
Pro Tips for Marine HVAC Design
- Consult with manufacturers early to confirm coating options and any performance derates.
- Specify coatings clearly in your documentation—don’t assume they are standard.
- Plan for maintenance: Regular inspections and cleaning are essential in salty environments, even with coatings.
- Educate your clients about the importance of these upgrades. They may cost more upfront but save significantly in the long run.
Designing HVAC systems for marine environments isn’t just about resisting rust—it’s about ensuring long-term performance, reliability, and safety. By specifying the right coatings, materials, and installation practices, you can protect your systems from the harshest coastal conditions.
