Blygold FAQ's

Does a Blygold coating affect the thermal resistance of a heat exchanger?

Yes, no matter what others may tell you, every corrosion protection system has an effect on thermal resistance. This is due to the fact that no coating on the market today has the same heat conductive capacity as pure metals such as aluminum and copper. To what extent a coating will affect the heat transfer depends on the type of coating, heat exchanger geometry, air velocity etc. Blygold coatings are heat conductive and applied at a very thin layer thickness. This results in a minimal influence on the thermal resistance and minimal pressure drop. Tests of Blygold coatings have shown influences ranging from 0 to 12% depending on face air velocity and coil geometry. Installations with existing corrosion problems after renovation with Blygold coatings show an improved heat exchange capacity. For normal situations we recommend using 3% as an average capacity loss.

For more information check Blygold Technical Study, Part 3

How does corrosion affect the capacity of my air-conditioning?

Corrosion will cause your air-conditioner to loose efficiency and capacity. The result is the air-conditioner will consume more energy and produce less cooling capacity. Your installation will perform the worst when you need it the most. Heat exchangers are extremely vulnerable to corrosion due to the combination of different metals in the heat exchanger (copper and aluminum) and the continuous exposure to pollution and corrosive elements in the environment. The heat transfer between the liquid/gas medium in the tubes and the outside air passing over the fins is reduced due to the corrosion of the aluminum. In addition, the pollution on the fins will reduce the airflow trough the heat exchanger significantly. To release all the absorbed heat from the air-conditioned space the system raises the condensing temperature/ pressure, this results in a higher temperature difference between the gas/liquid and the outside air. The resulting high condensing temperature/pressure is why the compressor of your airconditioner consumes more energy and will drop out faster in the summer.

For more information check Blygold Technical Study, Part 1

Are Blygold coatings resistant against every substance?

Blygold coatings are resistant to many substances in varying concentrations. Refer to the resistance list for specific resistance capabilities. If the substance in question does not appear on the list, contact the Blygold R&D Department.

Why is my air-conditioning unit corroding?

There may be any number of reasons why your air-conditioning unit is corroding. The heat exchanger in an air-conditioner is usually made from aluminum fins and copper tubes. With these two different metals, in combination with pollution and moisture, there is a huge potential for galvanic corrosion to take place. Aluminum will corrode rapidly around the copper tubes. Other corrosive agents and pollutants in the atmosphere, like sulfur, carbon oxide and nitrogen, are able to directly react with aluminum and copper. Huge volumes of air are forced trough the heat exchangers, this way heat exchangers are exposed to far more aggressive circumstances than other equipment.

For more information check Blygold Technical Study, Part 1, and 4

In which environment will corrosion occur?

Corrosion of heat exchangers will occur everywhere. The different metals (copper and aluminum) that are present create a huge potential for corrosion. The speed of the corrosion will be determined by several parameters with the environment as one of the most important. Corrosion will occur rapidly in coastal/marine environments, the salts from the sea will deteriorate aluminum and copper. Other high risk areas are industrial zones where concentrations of sulfur, carbon oxides and nitrogen are present. Examples of typical problem areas are waste water plants, paper plants, fertilizer plants, food processing industry, mining areas, PVC production plants, chemical production plants and oil refineries. The same conditions might occur close to high ways and in cities. Corrosion on heat exchangers will occur, in some environments it will not be visual for many years and only be present around copper tubes. In other environments heat exchangers need to be replaced only after 3 months.

For more information check Blygold Technical Study, Part 1, and 4

Is it necessary to clean my air-conditioning unit?

Yes. Units installed outside will most likely be exposed to pollution and potentially corrosive substances. Even units coated with Blygold protective coatings require periodic cleaning. That is why periodic maintenance is a requirement to maintain the Blygold Warranty. Units should be periodically cleaned with a mild (ph neutral) detergent and rinsed completely. The frequency of the periodic maintenance depends upon the location and environmental conditions in which the unit is installed.

Why does my conditioned air smell?

Odors permeating the conditioned air coming from the air conditioning are usually caused by dirt and even more bacteria and fungi (micro-organisms) accumulating and growing on cooling heat exchangers. Blygold offers a solution by creating a micro-organism repellent surface on the heat exchanging fins.

For more information check Blygold Technical Study, Part2

What is the difference between pre-coat (epoxy, vinyl) and Blygold?

Blygold’s coating is an aluminum-impregnated polyurethane, which is applied after the heat exchanger is assembled to allow for total coverage and complete penetration. Epoxy / vinyl coatings are inferior to polyurethane by there composition and the pre-coat process does not permit total coverage due to the cut edges being exposed after fabrication. Not only will pre-coat systems have a very temporally effect against corrosion, they will also reduce the initial capacity with 15 % due to the layer between copper and aluminum.

For more information check Blygold Technical Study, Part 4

How Are Blygold coatings applied?

Blygold coatings are applied by trained and certified applicators using a time-tested procedure and high-pressure air assisted air coat spray equipment. The special developed and standardized application techniques have proven to result into; equal layer thickness throughout coils, negligible pressure drop even on louvered fins and 100 % sealing fin-tube joints from environment.

Where can I buy the Blygold products?

Blygold corrosion protection systems can only be applied by certified and licensed applicators. The Blygold treatments of heat exchangers are available through an international network of Blygold Licensed Partners. They can be found by visiting the Blygold International website, www.Blygold.com or the Blygold America website, www.blygoldamerica.com. Several service products can be bought and applied by end users directly, examples are special cleaning agents and do-it-your-self kits for small units.

How long will it take to treat a heat exchanger with Blygold?

The time it takes to treat a heat exchanger will vary depending on the size and configuration of the unit. Blygold applicators make every effort to accommodate your scheduling requirements by providing efficient turn-around times. To apply Blygold’s high quality pre-treatment and coating procedure at least three days are required, total turn around time will depend on size, configuration etc. How long will a Blygold treated heat exchanger last? Independent laboratories have tested Blygold coatings under accelerated conditions. Blygold coatings withstand the ASTM B117, Salt Spray Test and the ASTM G85, Acid Salt Spray Test in excess of 3000 hours. Practical cases have shown Blygold treatments to last for 10 years. Individual exposure conditions vary greatly. Contact your nearest Blygold applicator if you have any particular concerns or questions regarding any extraordinary or unusual exposure conditions.

For more information check Blygold Technical Study, Part 4

How do Blygold treatments prevent capacity loss and increased energy consumption?

By minimally impacting heat transfer and conductivity and by providing lasting corrosion protection to prevent degradation of the function of the coil, Blygold treatment prevents capacity loss and increased energy consumption.

For more information check Blygold Technical Study, Part 1, and 3

Is a copper / copper heat exchanger the solution for corrosion?

A copper/ copper heat exchanger basically eliminates only one potential cause for corrosion, galvanic reaction. A copper / copper heat exchanger is still vulnerable to the corrosive effects of the environment. Once again, independent tests show that a bare copper / copper heat exchanger will not resist corrosive damage as well as a less-expensive aluminum / copper coil treated with Blygold coatings.

For more information check Blygold Technical Study, Part 4

How do I know if there is corrosion on my heat exchanger?

It should be visible in the form of white spots that do not come off with cleaning, pitting or other obvious degradation of the fin surface area or edges. For inspection on galvanic corrosion around the copper tube a bit more experience is required. With the use of a light and a small screwdriver one can already see a lot, the use of medical devices like endoscope or boroscope is even better. The presence of significant galvanic corrosion can also be seen on the power consumption gauge.

How much does a Blygold treatment cost?

As the time it takes to treat a heat exchanger will vary depending on the size and configuration of the unit, so does the cost. Blygold licensees will be able to give you an exact price. Keep in mind that heat exchangers consist of a tremendous amount of metals that need protective treatment. For example: standard condensing heat exchangers of 1 m2might have 80 m2 of surface to be coated.

What is the difference between the 4 different Blygold treatments?

Blygold Plus Tropic is a wax based coating that provides good corrosion protection, is very flexible and adhere to almost any surface. The product can be damaged mechanically due to it’s wax base. Product is especially suitable for applications on site and for renovations. After cleaning procedure a touch up is necessary to re-coat fin edges. Combined with yearly touch up several years of warranty are possible.

Blygold PoluAl is a poly-urethane coating with excellent corrosion protection and flexible and mechanical touch properties. Complicated application requires factory application preferably. Cleaning procedure will not damage the coating, touch up will normally not be necessary.

Blygold PoluAl High Temp. A special corrosion protection system to be applied in high temperature applications.

Blygold PoluAl MB A corrosion protection system that provides an additional dirt and microorganism repellent surface. The product is especially suitable on cooling coils to prevent corrosion and microorganism growth.

For more information check Blygold brochure, Heat exchanger protection or www.blygold.com