Modern fishing boats are
more or less floating food-processing factories. Most of the North European and Canadian fishing fleets operate in arctic
waters, where the outdoor temperatures can be very low;
-30°C or below. The climate
inside the ship is room temperature and the relative humidity, RH, is generally rather high due to the processing of fish.
is unavoidable that vapour penetrates through the vapour barriers and forms condensation in the insulation. The effect is
that the efficiency of the insulation is reduced and in many cases, the condensation water freezes. It happens that the ice
will be so heavy that the insulation bursts and falls down.
A coat of 1,5
– 2,0 mm KEFA Coating is sprayed on the metal surface under the Rockwool insulation. The KEFA coat adsorbs the condensation
water and stores it until the ambient situation allows the water to evaporate back into the air. The capacity of a KEFA coat
of the actual thickness is ~ 1,5 litre of water per m2, which has shown to be sufficient to keep the Rockwool insulation
In 1988 and 1989 four fishing
boats, NorØrn, Northern Eagle, Crystal Viking
and Crystal Clipper were insulated with GrafoTherm under the Rockwool insulation. In the spring of 2000, the insulation of
NorØrn was inspected. It was intact and no
moisture related damages - deterioration of insulation material, mould or rust - could be observed.