Maintenance and Responsibilities - Heat Pumps / Air Conditioning
Mitsubishi Electric Systems are built to world-class standards, but New Zealand's unique environment, from coastal salt air to geothermal activity, can be demanding on any equipment.
This guide explains how corrosion can affect your system, the responsibilities of everyone involved, and what you can do to ensure long-term performance and reliability.
Caring for Your Air Conditioning System
in New Zealand's Environment
Why Corrosion Matters in New Zealand
New Zealand is a unique place to live - and that comes with unique environmental challenges.
As a coastal and geothermal country, many parts of New Zealand are exposed to:
- Salt-laden sea air
- Geothermal sulphur gases
- Industrial or chemical airborne contaminants
- High humidity and moisture levels
These conditions can increase the risk of corrosion over time for many outdoor and indoor metal products, including air conditioning and heat pump systems.
Corrosion does not happen overnight, but without the right protection and maintenance, it can shorten the life of equipment installed in harsher environments.
Built to High Standards - From the Start
All Mitsubishi Electric Air Conditioning equipment - both indoor and outdoor units - is manufactured to exceptionally high international standards, including:
- ISO 9001 - Quality management systems
- ISO 14001 - Environmental management systems
- IEC 60335 - Electrical safety standards
- ISO 5149 - Refrigeration system safety and environmental requirements
- RoHS compliance - Restriction of hazardous substances
These standards ensure Mitsubishi Electric products are designed and manufactured using high-quality materials and robust factory corrosion protection suitable for most standard environments.
However, like all metal-based equipment, systems installed close to the sea, in geothermal areas, or exposed to corrosive air may require additional protection and care to ensure long-term reliability.
This is not a product flaw - it is simply a reality of operating equipment in challenging environments.
Indoor Units are Affected Too
It's a common misconception that corrosion only affects outdoor units.
In reality, indoor units can also be exposed to corrosive air, especially where:
- Fresh air is introduced via ventilation systems
- Doors and windows allow outside air into the building
- Buildings are located in coastal or geothermal regions
- Humidity levels are high
The air passing over indoor heat exchangers may carry salt, sulphur, or other contaminants, meaning indoor components also need to be considered when planning protection and maintenance.
Understanding Corrosion Zones in New Zealand
New Zealand uses recognised corrosion maps and zoning systems developed by organisations such as:
These maps classify areas from low (C1) to very high (C5) corrosion risk, based on factors like proximity to the coast, altitude, wind patterns, and industrial activity.
In higher-risk zones:
- Equipment may require additional corrosion protection
- More frequent maintenance may be recommended
- Long-term care becomes especially important
Your installer or service provider can help identify which corrosion zone applies to your location.
Why Additional Corrosion Protection May be Recommended
Mitsubishi Electric Systems are supplied with robust factory corrosion protection as standard.
In harsher environments, however, additional corrosion protection may be recommended to:
- Extend the life of indoor and outdoor components
- Reduce the risk of premature corrosion
- Protect your investment over the long term
Options may include:
- Factory-applied coatings (where available)
- Professionally applied aftermarket coatings
- Enhanced maintenance and cleaning regimes
Choosing additional protection is about future-proofing, especially in coastal or geothermal areas.
The Importance of Regular Maintenance
Ongoing maintenance plays a crucial role in corrosion prevention.
Regular servicing helps to:
- Remove salt, dust, and contaminants from coils and drain trays
- Prevent moisture build-up that accelerates corrosion, including galvanic corrosion
- Ensure drains, airflow, and filters operate correctly
- Identify early signs of wear before they become major issues
Think of maintenance as similar to washing and servicing a car near the coast - a small, regular effort that can make a big difference over time.
In Summary
- Mitsubishi Electric Systems are built to world-class standards
- New Zealand's environment can be challenging for any metal equipment
- Both indoor and outdoor units can be affected by corrosive air
- Corrosion risk varies by location and environment
- Additional protection and regular maintenance help maximise system life
With the right care, your Mitsubishi Electric System can deliver comfort and performance for many years to come.
Looking After Your Air Conditioning System
Roles & Responsibilities Explained
Working Together for Long-term Performance
To get the best long-term performance from any air conditioning or heat pump system, everyone plays a role.
This includes:
- The manufacturer
- The designer or installer
- The owner or building operator
Having a clear understanding and shared responsibility helps ensure systems are correctly selected, installed, protected, and maintained.
Manufacturer Responsibility
Mitsubishi Electric manufactures air conditioning equipment to some of the highest international standards in the industry, including ISO and IEC compliance.
This includes:
- High-quality materials
- Factory-applied corrosion protection suitable for standard environments
- Rigorous testing and quality control
Designer and Installer Responsibility
The designer or installer is responsible for:
- Assessing the environment where the system will be installed
- Considering corrosion risks based on location and site conditions
- Recommending additional corrosion protection where required
- Ensuring correct installation, drainage, airflow, and service access
This step is especially important in coastal, geothermal, or industrial areas.
Owner Responsibility – Ongoing Care
Once installed, the owner is responsible for:
- Regular servicing and maintenance
- Cleaning filters, coils, and drain systems
- Maintaining any applied corrosion protection
- Addressing issues early before damage occurs
Environmental conditions can change over time, and ongoing care helps protect the system throughout its life.
Why this Matters
Corrosion-related damage is almost always environmental, not a manufacturing issue.
Most corrosion-related failures are preventable with:
- Appropriate protection
- Good installation practices
- Regular maintenance
A Simple Message
Mitsubishi Electric Systems are built to last.
New Zealand's environment can be demanding.
With the right protection and care, your system can perform reliably for many years.
Black Diamond Technologies and Mitsubishi Electric are committed to supporting customers, installers, and designers with guidance, service options, and technical support to help protect your investment.
Corrosion & Care
Frequently Asked Questions
Corrosion is a natural process where metals gradually deteriorate when exposed to moisture, salt, sulphur, or other airborne contaminants.
In New Zealand, coastal air, geothermal activity, and certain industrial environments can increase the risk of corrosion over time. While Mitsubishi Electric Systems are built to very high standards, corrosion can affect any metal equipment if environmental conditions are challenging and ongoing care is not provided.
No. Corrosion is generally caused by environmental exposure and operating conditions, not by manufacturing defects.
Mitsubishi Electric equipment is manufactured to international quality and safety standards and includes factory corrosion protection suitable for most standard environments. In harsher environments, additional protection and maintenance may be required to ensure long-term performance.
Not always.
While outdoor units are more obviously exposed, indoor units can also be affected, particularly where:
- Fresh air or ventilation systems introduce outside air
- Doors and windows allow sea air indoors
- Buildings are located in coastal or geothermal regions
- Humidity levels are high
Because the air passing through indoor units can carry corrosive contaminants, both indoor and outdoor components need to be considered.
Living near the coast does not mean you will automatically have problems, but it does mean extra care is important.
Salt in the air can accelerate corrosion over time. In coastal or high-risk areas, your installer may recommend additional corrosion protection and more frequent maintenance to help protect your system.
Corrosion zones are classifications used across New Zealand to describe how aggressive the environment is for metal products.
These zones are based on recognised corrosion maps developed by organisations such as BRANZ and HERA, and they consider factors like:
- Distance from the coast
- Wind exposure
- Altitude
- Industrial or geothermal activity
Your installer or service provider can help identify the corrosion zone for your location and advise what level of protection and maintenance is appropriate.
Depending on the product and environment, options may include:
- Factory-applied corrosion coatings (where available)
- Professionally applied aftermarket protective coatings
- Enhanced maintenance and cleaning regimes
These measures help extend the life of the system in harsher environments and are particularly beneficial in coastal or geothermal areas.
BS coating is a factory-applied corrosion protection option available on certain Mitsubishi Electric outdoor units, such as City Multi systems. It is designed to improve resistance to coastal sea air.
Whether it is required depends on:
- Your location
- Environmental exposure
- The specific application
Your installer or designer can advise if BS coating or other protection measures are suitable for your installation.
Regular maintenance is extremely important.
Maintenance helps:
- Remove salt, dust, and contaminants from coils
- Prevent moisture build-up that accelerates corrosion
- Keep drains, airflow, and filters working correctly
- Identify early signs of wear before serious damage occurs
In higher-risk environments, maintenance may need to be carried out more frequently.
Speak to your installer about regular servicing options if you prefer regular maintenance to be carried out by them.
Service frequency depends on the environment and how the system is used.
As a general guide:
- Standard residential systems: at least annually
- Coastal, geothermal, or commercial systems: more frequent servicing may be recommended
Your service provider can advise a schedule appropriate to your location and system type.
In most cases, yes.
While corrosion cannot be completely eliminated in harsh environments, the risk can be significantly reduced through:
- Proper system selection and installation
- Appropriate corrosion protection
- Regular maintenance and cleaning
Most corrosion-related failures are preventable with the right approach.
Warranty coverage applies to manufacturing defects.
Where corrosion-related damage is caused by environmental exposure, insufficient protection, or lack of maintenance, it is not considered a manufacturing defect and may not be covered under warranty.
Maintenance records may be requested as part of any warranty assessment.
You can help protect your system by:
- Having it serviced regularly
- Keeping outdoor units clear of debris and vegetation
- Cleaning or replacing filters as recommended
- Addressing issues early rather than delaying repairs
- Following maintenance advice specific to your environment
Think of it like caring for a vehicle near the coast - a little extra attention goes a long way.
Your installer, service provider, or our Technical Support Team can help assess your environment and recommend appropriate protection and maintenance options.
Early advice can help avoid issues later and maximise the life of your system.