Boxoffice (Jul-Sep 1947)

Practical Principles of Theatre Air Conditioning 'Continued from page 35) shorter and better sized. The blowers were delivering nearly equal volumes of air but power measurements showed that the one connected with the longer duct system consumed fifteen horsepower while the other required only five. The cost for the additional ten horsepower for an average of ten hours daily use and at a 2.5c power rate amounts to over five hundred dollars per year, and the house has been operating for ten years. But — that is not all — this additional ten horsepower increased the electrical ‘•demand,” and because of the nature of a “demand” rate the cost of all power consumed by the theatre was increased. Heating There are three primary methods of heating which may be combined with one or more of several ways of obtaining delivery to the final point. These methods are — steam, hot water and hot air. Steam and hot water have the advantage that they can be delivered more easily and efficiently to points quite far from the source than can hot air. Further, they are easier to control and will not convey dust or hazardous gases which might escape from a defective combustion chamber. The form of final delivery to the room from steam or hot water sources may be by radiators, convectors, unit heaters, or as warm air by the air conditioning system. Another method that is sometimes proposed is called “radiant” heating and consists of the heating elements being placed in the floor construction. Several advantages are claimed for it but we should remember that for our purpose heat must be provided to temper fresh air for ventilation during cold weather, and that the method must be flexible and incur a minimum of lag in responding to controls to meet the rapidly changing conditions found in theatres. For serving large rooms where many people may congregate such as an auditorium, the central system wherein the heating is combined with the ventilation is most desirable because of its flexibility, ease of control, and rapid action. For foyers, lounges, and office areas certain types of convectors will serve most satisfactorily, while unit heaters are more suitable for entrances or lobbies. Cast iron radiators are sluggish in action and response to controls, and they create heavy convection currents of air which soon soil and stain the walls and furnishings above them unless equipped with suitable hoods. For these reasons their use should be avoided in locations where such results would be undesirable or harmful. In existing cases where such trouble is experienced, it can be greatly reduced by installing a shield at a slight angle just above the radiator, and it should be of sufficient width to direct the stream of rising air away from the wall. Some styles of convector grilles permit the same difficulty to arise, but several manufacturers produce convector enclosures which incorporate narrow horizontal vanes or louvers in the openings which direct the heated air out and away from the wail thus practically eliminating this complaint. If forced hot air or a central system is used for heating then provision must be made for recirculation of the air This can be done by means of ducts or tunnels leading from the intake side of the blower to openings in or near the floor line at points where cold air collects. In theatre auditoriums where sloping floors are prevalent the essential point where cold air collects is at or near the stage and an ample opening should be placed in this locality. In theatres having a balcony, circulation of air under the balcony projection may be aided in some situations by placing some return openings behind the last row of seats. Large stages with high lofts are a source of great heat loss and objectionable drafts. If a stage is no longer needed for large presentations drafts can be eliminated and a saving effected in fuel costs by enclosing the entire area from the screen to the proscenium opening with drapes, or permanent construction if feasible. Fifth Installment; “Ventilation, Cooling Effects and Controls” will be covered by Mr. Frantz in the next (fifth) of this series of factual articles on Theatre Air Conditioning, which are based on the author’s actual experience in the maintenance of temperature control in theatres.— Editor. ‘‘A Smash Hit! Booked in Theatres Coast to Coast f » OOOPLCs FORTnA^CiDE Reg. U.S. Pat. Office. Patents applied for. “The World’s Finest and Newest” ODORLESS ANTI-INFECTIVE & DEODORANT With “Triple Action” Feature Built Right in one Solution. (1) ODORLESS DEODORANT (2) ODORLESS GERMICIDE (3) ODORLESS FUNGICIDE (SCALP "RINGWORM") Solves Problem of “Tactful” Sanitation. Obvious Efforts Frighten Patrons MULTIPLE USES IN THEATRE HOUSEKEEPING 1 Spray plumbing. Eliminates blocks. Non-corrosive to traps. 2. Spray air-conditioning fan and vents against bad air. 3. Spray seats against scalp ringworm and body odors. Spray floor between seats before brooming. 4. Upset stomach odors on seats and carpet eliminated without injury to color or fabric. 5. Instill in mop water for microscopically-clean and deodorized floors and mop. ECONOMICAL; ONE CASE OF 4 GALLONS MAKES 40 GALLONS OF EFFECTIVE 1:10 DILUTION USED BY LARGE CIRCUITS. INCLUDING B & K AND WARNER BROS. Accept no substitute. Fort-A-Cide i s compounded like a Doctor's prescription. It is a secret formula. Member of ORDER 4 GALLONS AND A 3-QUART "SPRAYMASTER'' FROM YOUR SUPPLY DEALER OR CIRCUIT OFFICE TODAY. DISEASE MAY STRIKE TOMORROW! (If your dealer or Circuit Office does not earry Fort-A-Cide, ask them to order it.) FORT-A-CIDE CORP., CHARLES P. HUGHES, PRES., IGO E. ILLINOIS ST., CHICAGO 11, ILLINOIS 42 The MODERN THEATRE SECTION