No_2_April_and_May__1941 — Page 21

Hong Kong Builder

The installation consists principally of three parts: 1. The main air conditioning plant for the store on the ground floor and the offices on the mezzanine

floor.

2. An independent air conditioning plant for the Cafeteria located on the ground floor balcony. 3. A cold storage plant for the storage of perishable

goods.

The main air conditioning plant consists of a 6-cylinder York W-type Freon Compressor, driven by a 50 H.P. Synchronous motor, and an Evaporative Condenser which takes the place of an ordinary condenser. Air is cooled, dehumidified and filtered in the air cooling chamber and then distributed to the conditioned space through a set of ducts by means of a multivane fan driven by a 7 H.P. motor. The ducts are built into the building, plastered and decorated to conform with the interior decoration.

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Special diffusers are used at each air outlet to insure even distribution of conditioned air. The Freon compressor is equipped with a two-step partial by-pass control which automatically cuts down the power consumption of the plant at light loads. The full load capacity of this plant is approximately 60 tons of refrigeration and the total amount of air circulated is approximately 12,000 cu.ft. per minute. Due to different load conditions, the Cafeteria is conditioned by a separate plant which consists of two York 10 H.P. Freon condensing units, an Evaporative Condenser and a sectional air conditioner. The condensing units and Evaporative Condenser are located inside the basement, while the conditioner is located on the balcony. Approxi- mately 6,000 cu.ft. of air per minute is supplied from the conditioner to the conditioned space through ducts installed inside the building, with outlet diffusers similar to those of the main plant. The use of two condensing units makes it possible to utilize one machine during light loads.

Photograph of the shop on the main floor, looking from the entrance towards the Cafeteria steps.

Not the least feature of the attractiveness of the shop are the McCray refrigerated showcases in which all the perishable merchandise is kept,

The cold storage plant con- sists of a York 10 H.P. Freon condensing unit, an Evapora- tive Condenser and Freon direct expansion copper coils to cool four cold storage rooms and опе corridor. The high and low temperature rooms are insulated with 6" and 8" of corkboard respectively. The high temperature rooms are controlled by solenoid valves to prevent their temperatures from dropping too low.

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The entire installation characterized by its use of Evaporative Condensers which eliminate the use of large quanti- ties of condensing water which would otherwise be required. The scarcity of a fresh water supply in the Colony presents a very difficult problem where air conditioning and refrigerat- ing installations are concerned. However, this problem is entirely solved by the use of Evaporative Condensers.

For the purpose of condensa- tion, the same water is recircu- lated in the Evaporative Con- denser, only a small portion of it being evaporated. Fresh air is brought in at room tempera- ture and discharged at a high temperature and saturated with moisture. With the Evaporative Condensers located in the base- ment, fresh air and exhaust air ducts are brought into the base- ment for circulating the neces- sary amount of air.

Quiet operating motors are used throughout the entire in- stallation and soundproof founda- tions are utilized where necess- ary. The W-type compressor, being the first of its kind installed in the Orient, is characteristic of its quiet opera- tion and light foundation which make it possible for upper floor installation, although, in this particular case, it is located in the basement.

Another feature in this in- stallation is the superiority of Freon over any other refrigerant for plants of this nature. All Freon mains have been properly sized. tested and installed by experts. Automatic thermosta- tic expansion valves are used throughout all the evaporators,