-3- 



Two 250-watt infrared and two 15-watt ultraviolet lamps are 

 installed on the wall near the ceiling. The infrared lights are adjust- 

 able so that they can be pointed in any desired direction. The starter 

 and ballast for the ultraviolet lights are on top of the exterior of the 

 cabinet. There is also a time clock outside the cabinet to give any 

 desired operation of the lights per 24-hour period. A weatherproof 

 socket for a standard light bulb is installed near the ceiling in one 

 corner of the room and a weatherproof plug -in socket near the floor. 



Mounted on the wall of each cabinet is an aspirator box of stainless 

 steel which contains a small blower that draws air over a thermocouple 

 and a humidity sensing element. 



Air -Conditioning Equipment 



The refrigeration compressor is powered by a 10 -horsepower, two- 

 speed motor, 1450 and 725 r.p.m. Monochlorodifluoromethane is used 

 as the refrigerant. This compressor has automatic capacity unloading, 

 permitting from one to four of its cylinders to operate, depending upon 

 the load. It is provided with water-cooled cylinder heads to prevent 

 overheating when operating at low suction pressures. 



An evaporative condenser is suspended above the compressor unit 

 from angle iron to provide the necessary refrigerant- condensing 

 capacity. A sump tank is located below the coil to retain cooling water 

 for recycling. Constant bleed-off of water prevents high concentration 

 of minerals left from evaporation of the water. A float valve provides 

 the necessary make-up water. To conserve the water, the supply 

 through this valve is first taken through the compressor water-cooled 

 heads, and any additional water for the compressor heads is drawn 

 from the condenser sump. After it has circulated through the com- 

 pressor heads, the cooling water is returned to the sump. A Kramer 

 receiver large enough to store the entire charge of refrigerant is 

 installed beneath the evaporative condenser. 



In one wall of the cabinet are two air -handling units, mounted side 

 by side with an insulated partition between them. Each is equipped 

 with a large expansion coil having copper tubes and aluminum fins 

 with l/4-inch spacing, and over each unit are a 1/2 -horsepower, 3 -phase 

 motor driving a squirrel- cage blower and three finned strip heaters 

 having a total capacity of 8600 watts for air reheat. 



Each coil is divided into three sections, each provided with an 

 expansion valve so that there are three refrigerant circuits. Two 

 circuits each has one-fifth and one circuit has three-fifths of the total 

 refrigerating surface. By various combinations of these circuits it is 

 possible to obtain increments of refrigeration in fifths of the total 

 capacity of the coil. The first two refrigeration circuits are controlled 

 by thermostatic expansion valves of 1-ton capacity, and the third circuit 

 by a valve of 3 -ton capacity. 



