Issue:
What is specifications for the CompleteCoat Option?
Resolution:
CompleteCoat is an available option on CGAM, RTAC, RTAE, RTAF and the condenser supplied with RTUD.
Currently we have separate coating specs for RTPF coil and MCHE Coils. Even though the coating material and process are same, we have defined them differently from spec perspective.
This spec is for MCHE coils used on CGAM and RTAF.
See CompleteCoat specifications for RTPF coils for the RTPF spec.
Color: Black
Dry Film Thickness: ASTM D7091 0.0005-0.0016"
Gloss – 60: ASTM D523-89 65-90%
Pencil Hardness: ASTM D3363-00 2H Minimum
Cross Hatch Adhesion: ASTM D3359-97 4B-5B
Impact Resistance: ASTM D2794-93 160 in/lbs Direct
Salt Spray: ASTM G85 2400 Hours to hold 1950 psi burst pressure; ASTM B117 for 5000 hours without leak.
Water Immersion: ASTM D870-02 > 1000 Hours at 100 degrees F
UV-A resistant: ASTM G155 2000 Hours
Background: CompleteCoat provides the corrosion protection you need without the worry of performance degradation or coating breakdown. It is a tough epoxy coating that uniformly covers all condenser coil surfaces. This advanced material is flexible, fixing the thermal cracking problems of phenolics, and avoids bridging problems encountered with application of earlier, more viscous coatings.
A coil treated with CompleteCoat is resistant to a wide range of environmental and industrial contaminants. It is proven to stand up to a 5,000-hour salt spray exposure test. Because of its uniform thin coating characteristic, the coil's heat transfer is reduced less than one percent. Air-cooled chillers with the CompleteCoat option keep their UL listing and do not need to be re-rated.
Chemical Resistance Chart is attached.
The key to this protective system is the advanced coating material itself, and the fact that it is bonded to the entire completed coil using an electrochemical application method. All metal areas are uniformly coated. The treated coil is resistant to a wide range of chemicals and protects the coil in temperatures from negative 40°F to positive 325°F. This condenser coil coating system makes the Trane air-cooled chiller the best choice for an even wider range of applications. Because of the potential for corrosion of air-cooled condenser coils, certain environments have traditionally limited the use of air-cooled chillers. This includes coastal applications that are exposed to salt spray, and a wide variety of industrial environments. In such areas there may be airborne corrosive salts, acids, bases and/or other chemicals that shorten the life of air-cooled heat exchangers.
Until now the choices were to simply accept the shortened life of the aluminum heat exchanger or use a variety of coatings that fell short on corrosion protection and chiller performance. Phenolic coatings offer some protection from corrosion but provide inconsistent coverage and can break down in challenging environments. Further, phenolic coatings significantly reduce the heat exchange value of the coil (2-4%), requiring more energy usage and a larger unit to make up for the peak load performance loss. Because of their brittle nature, phenolic coatings can deteriorate from thermal flexing or from an abrasive environment.
The option to spray various coatings on in the field has also been available. This can provide a first cost and delivery benefit over full coatings. These options can be very inconsistent in coverage and generally provide protection mainly on the visible surfaces of the coils, allowing the interior fins and coils to corrode at un-coated rate.
Another option that has been available is epoxy pre-coated fin stock. This generally provides the largest first cost and delivery benefit when compared to other coating options. It does provide protection in low to moderately corrosive environments. The lack of coating on the edge of the fins, the condenser frame and the coil heads makes this option less desirable when corrosion is a large concern.
Warranty: The Trane factories do not provide a warranty for the Complete Coat option used to coat condenser fins.
Original Document: DOC-113265