By Richard Stratton
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.
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.
Condensation Issues
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.
Traditional Solution
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'sF/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