Reduce Condensation and Improve Insulation
We all know that watching paint dry is ... well, as interesting as watching paint dry. But the ability to control condensation with ceramic insulation coating while keeping traditional materials effective, all while protecting against corrosion for decades of service, might make paint more exciting.
Ships are perfect condensation generators, with cold surfaces and high volumes of water vapor in the air. Unless you can control humidity in spaces, there will be condensation. Using the right thickness of ceramic insulation coating in all spaces (unheated and heated) takes the chill off surfaces and practically eliminates condensation. This coating also preserves blanket insulation's performance by reducing wet surface contact.
Condensation all begins with "dew point", occurring when water vapor in air is cooled to the point where it converts to water, forming rain or in the case of cold ship surfaces, droplets of water. On absorbent surfaces like rock wool insulation, water soaks in until saturated with moisture. On hard surfaces, the moisture drips into the material or is absorbed directly into the material.
The traditional solution of installing mineral wool for condensation control is not much better than installing sponges on the structure. Yet that's still a common practice for treating condensation in spaces. Even in warm spaces, traditional insulation absorbs moisture until it comes into balance with the airborne level of relative humidity. Since that humidity level is high on many ships (80%-95%), this converts traditional insulation into a moisture-saturated blanket, losing significant insulation value and also contributing to corrosion.
For fire safety use, mineral wool is a vital component. However, it doesn't control condensation and has to be protected from direct contact with moisture for thermal insulation. It can perform well when combined with ceramic coating.
Ceramic Coating Solution
Ceramic coating takes the chill off surfaces with a thin radiant heat barrier that raises surface temperature above the dew point to prevent or almost eliminate condensation. Ceramic coating also improves traditional insulation performance by keeping it dryer and adding a radiant barrier to the thermal envelope.
The basic fact is that ceramic insulation coating is not as good as dry blanket insulation for retaining heat. However, insulation blanket does not stay dry, and thin insulation coating provides a basic level of thermal performance in spite of exposure to wet conditions. Ceramic coating is very effective for its thickness and blocks condensation by raising cold surface temperatures above dew point to prevent water droplets from forming. On hot equipment insulation applications up to 350F/177C, thermal efficiency results show a range of savings from 15 to 35 percent.
A treatment used extensively by Kvichak Marine and West Coast Insulation provides a good example of a hybrid insulation solution that leverages mass-based insulation and radiant barrier materials. This combines ceramic insulation coating on 100 percent of stiffeners and flat panels at 40-plus thousandths of an inch, or mils, combined with 2-inch fiberglass foam or blanket on flat panels, and has been used successfully for several years in hot and cold climates.
The first use of thin insulation coatings in the form of latex paint saturated with ceramic beads began almost 20 years ago with a Georgia painting contractor, Mr. Alvin Beatty. He first sprayed the coating on industrial equipment to improve heat retention and reduce solar heat loading on buildings. Marine coating use began on the Southeast Gulf region's workboats, for passive condensation control and primary insulation, and thus started the steady adoption of thin insulation coating on vessels.
Of Puget Sound's shipyards, Dakota Creek Industries has the most experience with ceramic insulation coating, using the system as primary insulation as well as condensation control. According to Dakota Creek's Ron Daniels, using CIC for insulation represents a 30 percent savings over conventional materials at $45/gallon, based on faster spray application compared to much slower conventional material installation. DCI's use has been on shipboard applications ranging from pilothouse and living quarter insulation to condensing bulkheads and chill water lines to heated bunker fuel tanks.
When the F/V Golden Alaska factory was rebuilt, wet rock wool was replaced with ceramic insulation coating. Airless application of 80 mils of ceramic coating on 11,000 square feet of surface was completed in 48 hours, compared to the typical 2 weeks required for conventional materials. Ron Leighton, port engineer on the Golden Alaska, continues to use CIC for condensation control on chill water lines, steam pipes and other surfaces throughout the vessel.
Local vessels using ceramic insulation coating range from Seattle's fireboat Leschi, police boat Patrol #9, American Seafood's F/V Northern Jaeger, F/V Katie Ann and others. Shipyards include Dakota Creek Industries, Kvichak Marine, Vigor, Rozema Brothers, Seaspan and Allied in Vancouver, and Sound Propeller used the coating to insulate their container-based welding shop.
Other Industrial Applications
Insulating shipping container-based living quarters, work spaces or to improve freezer performance are other common uses for ceramic insulation coating. Food processors use ceramic coating extensively to insulate cooking equipment and steam lines where regular washing and sterilization procedures wreck traditional materials. Use on buildings for condensation control on cold walls and to reduce solar heat loading on the outside of building envelopes is also popular.
How insulation works
Thin insulation coating works primarily by blocking radiant heat transfer in the infrared light spectrum similar to how thin oxide coatings block infrared light on Low-E windows. Mass-based, conductive insulation materials like mineral wool use low-density mass to slow heat flow from the warm side to the cold side. Those materials' absorption of thermal energy results in heat storage within the blanket, making it a heat sink or thermal battery on the perimeter of spaces. That's a valuable characteristic for storing heat in a living space and slowing its penetration to a cold space. Inexpensive and readily available, it's easy to install and also has good noise absorption qualities, making it a good choice for surrounding an engine or machinery space.
Ceramic-based insulation coating combines radiant barrier properties with low transmittance, the characteristic of ceramic coffee cups that allows us to drink hot liquids more comfortably compared to tin cups. Ceramic coating can be applied at almost half the cost of mineral wool, protects 100 percent of surfaces and eliminates the need to wrap stiffeners with insulation on non-fire boundaries. Ceramic coating also helps prevent corrosion by keeping surfaces dryer. While not as thermally effective in retaining heat as mass-based insulation, ceramic coating doesn't degrade from exposure to wet conditions, insulating where other options fail. By protecting conventional materials from condensation, ceramic coating improves overall performance and leverages both types of materials thermal advantages.
Return on Investment
Ceramic insulation coating has proven performance as marine insulation, costs less and installs faster than conventional. Service lifespan can be measured in decades and application cost is as low as half the cost of traditional materials. Ceramic insulation coating has proven to be the only viable solution for unheated spaces where condensation soaks conventional insulation and fails. Ceramic insulation coating also preserves conventional materials to provide the highest thermal efficiency and has proven track record for living quarters and workspaces. Chill water lines, steam lines, heat exchangers and other cold or hot surfaces up to 350F are also proven applications for ceramic insulation coating.
With the advances in ceramic coating technology, the right application can reduce maintenance and repair costs due to corrosion. Watching paint dry is still not very interesting, but if the type of paint you apply to the condensation-prone spaces on your vessel reduce your operating costs, at least the effort can be profitable.
Richard Stratton is the managing partner of Advanced Coating Solutions, offering improved insulation performance on ships and at food processors in the Pacific Northwest. He was born in Tacoma and raised in Longview, Washington, although he fished out of Uganik Bay, Kodiak during summers. He can be contacted at RichardS@Latitude47.com