Generally insulation tests are held to confirm the insulation effect of chamber walls after cooling down. From the records with self-recording thermometers during insulation tests, we derived a temperature-hour formula, which can be used to confirm the insulation effect in chambers. We also obtained the values 0.365 and 0.353 kcal/hr m^2℃ as heat transmission coefficient k for refrigerated cargo chambers by the tests in the cargo ships A and B. These values are about 2.2 times as much as the value calculated from conductivity coefficient of each insulation material. Heat transmission is increased by effects of steel structure, e.g. beams, frames and stiffeners, and supporting timbers in insulation walls.
