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The Pamphlet Collection of Sir Robert Stout: Volume 62

Cool-chambers

Cool-chambers.

I found the chambers provided clean and sweet. The floor of one was wet: at my suggestion sawdust was spread on it to absorb the moisture.

A great defect was at once apparent, no means of ventilation being provided for the exit of the carbonic-acid gas given off from the fruit. The chambers are closed by air-tight doors, and a great part of the fruit must necessarily remain in a stagnant bath of gas, which must damage it more or less. There may be a little circulation at the top of the chambers caused by the ingress and egress of the cold air, but, owing to the greater weight of the carbonic-acid gas, this draught cannot descend to the bottom of the chamber: page 7 were the cold-air trunks placed on the floor, instead of at the roofs of the chambers, they would no doubt draw off the gas.

Another defect is, that, while the chambers are insulated to prevent heat from entering from outside, the cold-air trunks that pass through the chambers, conveying air at a temperature of from 30° to 60° below zero, are simply made of inch timber, and have no insulation to prevent this extreme cold from penetrating and freezing the fruit stowed close to the trunks. Certainly battens were placed between the trunks and the cases, but that I consider insufficient. At my suggestion some old canvas was placed over the cases immediately in front and below the vent-holes by which the cold air gains access to the chambers, in order to prevent the air playing upon and freezing the fruit in the case immediately in front of the hole, and also to catch the snow which occasionally blows through and falls on the case under the hole.

In the foregoing I think I have found the cause of every here and there a case in the London sales catalogues being marked "frost-bitten," and selling for two or three shillings, when others are bringing 12s. to 18s. Another defect in the cooling is that the chambers are only cooled from one side: in consequence the temperature is much higher—from 10° to 20°—at the side of the chamber where the air finds egress into the return trunks, than it is at the other side of the chamber. It would be an improvement if the cold air could be admitted at either side alternately. In my opinion an entire change in the method of cooling chambers for the safe conveyance of both fruit and cheese is required, which change I think should be in the direction of ventilating-fans circulating a large body of cool air, 40° Fahr., through the chamber, and not, as at present, forcing in a small quantity of freezing air 30° or 40° below-zero, with the object of gradually cooling the mass of stagnant air and gas in the chamber.