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1945 Theatre Catalog, 4th Edition, Page 403 (379)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 403
Page 403

1945 Theatre Catalog, 4th Edition, Page 403

Maintenance of Air-Conditioning Equipment

Brief Summary of the Things to Be Done To Keep Machinery in Good Running Order

Approximately ten to twenty per cent of the cost of a building, heated in winter and cooled in summer, is spent on the heating, ventilation, and air-conditioning installation. Yet this expensive item is usually neglected and allowed to deteriorate more rapidly than is necessary if the equipment received proper maintenance.


Water, is one of the most destructive agents. In conjunction with heating and cooling, water is frequently used in the system, and, unless the system is properly designed, constructed, and maintained, the water accelerates the deterioration of those parts of the system with which it comes in contact.

Too, whenever quantities of water are used over continuing periods of time, accumulations of bacteria and algae (green slime) are apt to result. The conditions under which these things come to pass vary with each water source and set of equipment. Accordingly, every operator of air conditioning should make sure that such accumulations are not forming. If they are, he should immediately call in his air-conditioning engineer for advice on overcoming this situation.

The Basic Rules

The following basic rules should serve as a common yardstick, covering the maintenance of all mechanical equipment.

(1) Keep all mechanical equipment clean and free from dirt and foreign matter.

(2) Keep all surfaces clean and painted with paint which will act as a protective coating to the material of which the parts are made.

(3) Lubricate all working parts at regular intervals.

(4) Keep water, dirt, and foreign matter out of and away from all electric motors.

A great deal of this work can be done with common labor, if the theatreman knows how it should be done. It is safe to say that pennies spent on maintenance will save dollars on repairs and replacements.

Before Calling the Serviceman

When calling a serviceman, be sure to call one who knows his business and completely understands how your system was designed to operate. You may avoid some unnecessary trips of the serviceman if you will check the following items before you place a call for him.

If the compressor will not start (1) Has the main switch been opened?

(2) Has a fuse blown out?

(3) Is the power off in the theatre?


(4) If a self-contained unit, is it plugged in?

If the motor continues to run (1) Is the belt broken or removed from the pulley?

If a water-cooled compressor persistently stops after running a short time#

(1) Has the water supply been turned 01??

(2) Are the water lines frozen?

(3) Is there sufficient circulation of air around the compressor?

(4) Is air circulation in the conditioned area blocked?

(5) Is it due to some temporary overload on the equipment, or some other condition which corrects itself?

However, whenever you are in doubt as to the proper operation of your equipment, do not take any chances! Call your serviceman at once!


The following paragraphs discuss in brief salient points in the maintenance of complete air-conditioning equipment. However, included are most of the items comprising other air-cooling and ventilation systems.

Air Filters

Filters consist of mesh-like metal, glass wool, or cloth contained in a frame work. The air passes through the material and is cleaned. Filters, in airconditioning equipment, may be of one of two types. One is a throw-away, readily identified by the cardboard framing and inexpensive construction; the other consists of a metal frame and filtering material. As the filters become dusty, tending to cut down the volume of conditioned air passing through the system, they should be cleaned at regular intervals. Throwaway filters should be replaced regularly.

Air Infiltration

Large quantities of air leak into theatres from outdoors. Leakage occurs around windows and doors, and even through walls which are not tightly built. As all air which is brought in from the outside must be conditioned, the leakage should be kept at a minimum. Keep windows and doors closed, so that leakage from outdoors will be kept as small as possible. Locking windows often helps air-tightness.


There are one or more bearings in all units which have fans, motors, compressors, or other moving parts. Use only clean, grit-free lubricant for bearings. Do not use an excessive amount, as too much lubricant is harmful as well as

THE FILTER SECTIONS, shown at the left, are ready to be moved into place and bolted to the coil system. As the filters become dusty, they tend to cut down the volume of air passing through them. When particularly dirty, the filters are no longer capable of performing the function for which they are installed and, indeed, may themselves become the source of dust pumped back into auditorium. In cleaning, follow the manufacturer's rules.


1945 Theatre Catalog, 4th Edition, Page 403