Daikin solutions to corrosive environments

We all know energy efficiency and reliability are key aspects when it comes to choosing chillers or equipment in general for an HVAC project. The geographical location where the equipment will be installed, though, can be an equally important aspect.

All those installations near the sea coast or in those settings where units are exposed to humidity, salt, and other corrosive agents in the atmosphere, need to be properly equipped to resist corrosion from those agents.

Daikin, as world leader in the air conditioning and HVAC sector, is concerned with these aspects, because being able to face these aspects, means being able to ensure the success of HVAC projects executed in corrosive environments. It means ensuring customer satisfaction.

Corrosion is a very common cause of failure in all those HVAC systems installed in potentially corrosive outdoor environments. Saline coastal environments, large processing facilities like refineries, heavy industrial production areas, auto emissions and power generation facilities, they all release a variety of contaminants that can cause corrosion.

Corrosion can affect heat exchangers and condenser coils, which are known to fail rapidly in corrosive environments. So, to ensure the durability and reliability of the HVAC equipment installed in those environments, protection from aggressive elements is needed.

Let’s take data centers as an example. Those are sensitive facilities, where huge quantities of information is stored and where unplanned down-time could cost hundreds of thousands of Euros. It goes without saying that a sensitive facility like a data center, when located in potentially corrosive environments, needs special precautions. To ensure that facilities like these operate as they are intended, corrosion control is essential.

Daikin addresses the problem with a few different options, which, depending on the characteristics of the installation site, guarantee proper protection of the equipment, also ensuring its durability and reliability.

Specifically, Daikin offers four different levels of protection against corrosion:





Blygold treatment


Blue-coat and Alucoat, ensure good protection in mildly corrosive environments, and are used respectively on aluminium microchannel condenser coils and copper-aluminium condenser coils.

The Blue-coat option – widely used on Daikin EWAD-T and EWAD-M chiller ranges, for instance – is the result of a uniform and durable epoxy coating, which enhances coils resistance to corrosive agents and is recommended in all those applications presenting moderate risk of corrosion.

Alucoat protection, then, prevents equipment’s corrosion with the separation of copper tubes from aluminium fins thanks to a thin layer of acrylic anticorrosion coating, which breakes the electrical connection, preventing galvanic corrosion. It is an option used on Daikin EWYD-BZ range, for example, and it is ideal for all those applications that need good protection in mildly corrosive environments.

For highly corrosive environments such as costal environments and heavy industrial production areas, E-coating and Blygold treatment (Blygold PoluAl XT) – both considered top level protections – are particularly suited options. They are respectively used on aluminium microchannel coils and copper-aluminium coils.

With the E-coating option – successfully used on Daikin EWAT-B, EWAH-TZ for example – the exchanger is fully protected by a uniform layer of epoxy polymers applied all over the exchanger surface. The coating is then further treated with an additional UV top-coating applied on the coil surface.

It is a treatment particularly suited for extremely corrosive environments like highly polluted urban areas and highly corrosive coastal and industrial areas.

Similarly, the Blygold treatment (Blygold PoluAl XT), a polyurethane coating impregnated with a metallic pigment, provides a long-lasting corrosion and UV protection to installed in highly corrosive areas, and it is used for copper-aluminium coils.

As an alternative to coatings, Daikin also offers the Cu – Cu CONDENSER COIL option – the highest level of corrosion control. With this option condenser coils, being made of copper only – both tubes and fins – are not subject to galvanic corrosion. It is an option particularly suited to prevent coastal corrosion and give durability to units’ components in unpolluted marine environments and Middle East projects. In fact, it is a quite relevant option for all those units operating in the desert.

This option really helps extending the life of a heat exchanger in those situations, but it is not suggested for polluted or industrial applications, since pollutants generally affect copper integrity.

Are you interested in exploring Daikin chillers and AHUs options? Check them out on our online product finder, where you will be able to find all the options available for the different technologies Daikin Applied Europe offers.