Performing Theaters

General

Performing Arts Theater

These are also referred to as legitimate theaters. Presentations can include stage drama productions, ballet, modern dance, films, opera, and symphony and modern rock concerts.

Older theaters, like movie houses, can be very elaborately decorated, requiring great care in locating air distribution systems. They are different from movie theaters in several ways. Performances are seldom continuous. They are usually separated by several hours. Most operate with a full or near-full house. There are 15 to 20 minute intermissions with the lobbies used for drinking and socializing. Background noise control is also more important than in a movie theater.

The principal areas include the orchestra (main) seating section, balconies and loges, orchestra pit, lobby areas, ticket (box) and administration offices, and stage. Other areas include the stage manager's and prompter's locations, the control board area, and the dressing rooms, plus the loading docks adjacent to stages.

The stage is a separate problem, which includes highly variable stage lighting, intricate, delicate, and varying scenery from one scene to another, plus the problem of keeping scenery and curtains from fluttering, and the main curtain from billowing when lowered.

HVAC

Because of the intermittent usage, theaters commonly experience a peak cooling load for only a few hours. A thermal chilled water or ice storage system may be an excellent application. In addition to reducing demand, the chillers may not need to operate during performances, thus reducing noise interference. As performances are separated by several hours, precooling may be applicable, particularly for afternoon performances. Noise control in the main hall is more important than in a movie theater.

The cooling load occurring during the 15 to 20 minute intermissions, with people crowding in the lobbies used for drinking and socializing may set the design load. The density can be as much as 5 sq. ft. per person.

The stage area presents several separate problems. The highly variable stage lighting is a major contributor to the cooling load. Intricate, delicate and varying scenery presents air distribution problems. Actors can perform at widely varying levels of exertion. Lighting loads at stage level can be handled by exhausting air around the lights. Conditioned air is usually delivered, using numerous supply registers, from the low side and backstage with numerous return or exhaust registers at the lights. Low velocities are essential to keep scenery and curtains from fluttering.

Air balancing is also needed to avoid chimney effects that might cause the main curtain to billow when it is lowered. Spot cooling may also be needed at the stage manager's and prompter's locations, and at the control board area. Individual units are often considered for the dressing rooms, if they can't be supplied from the main air system with individual room control.

Loading docks adjacent to stages also need to be heated in cold climates. These doors may be open for long periods while scenery is being loaded or unloaded. Local codes should be followed for emergency exhausts or skylights, and for fire protection and safety requirements.

Typical System

Most larger theaters use a central chilled/hot water system serving air handling units for each zone. As a cooling load can exist all year long in many areas, air-cooled chiller packages located outdoors are isolated from the house and its occupants, and no cooling tower with its attendant water use problems is required. Low-ambient operation controls should be supplied. Variable speed drives on secondary water pumps further reduce operating costs. Air filtration systems of 25% to 30% pre-filters and 85% final filters are recommended.

If air supply is discharged at low velocity below people's seats, supply air temperatures below 65°F could create discomfort.

Recommendations/Energy Services Opportunities

Opportunities include:

  • Older inefficient systems should be investigated for upgrading or replacement, particularly if CFC refrigerants are used.
  • Renovate older buildings with modern heating and cooling systems, and consider adding thermal storage.
  • Retrofit with heat reclaim coils or air-to-air heat recovery devices. Such recovery devices can reduce energy consumption by transferring 40 to 80% of the sensible and latent heat between the exhaust air and supply air streams.
  • Retrofit "free cooling" heat exchanger in a tower/chilled water plant system.
  • Add energy management systems with a central panel may allow individual air-conditioning systems or units to be monitored for maintenance and operating purposes.

Water Heating

Hot water is used for cleanup, dressing room showers, and rest rooms. Hot water consumption varies significantly among individual facilities. If a restaurant in included in the building, it should be handled separately.

Typical System

Water heating is not a major energy user. Most water heating is done separately from the building heating system using direct resistance or gas heaters, and in some cases, point-of-use heaters.

Recommendations/Energy Services Opportunities

If existing water heating systems are inefficient or inadequate, replace with modern efficient equipment. Also add better insulation on storage tanks, or timer controls. The ASHRAE Applications Handbook Chapter on Service Water Heating publishes typical hot water use data as well as estimating procedures.

Lighting

The majority of lighting tends toward incandescent because of its dimming flexibility. Most stage lights are also incandescent for the same reason. The lobby area may have some fluorescent lighting, but more likely has incandescent spot lights.

Another reason that fluorescent lighting has not been used in stage lighting is the strobing effect that results from magnetic ballast. This effect is invisible to the eye, but can cause irregularities in film. However, the new electronic ballast has eliminated this effect and the use of fluorescents greatly reduces the heat gain from the stage lights. A television station in Atlanta reduced their news stage lighting from slightly over 100 kW to slightly over 10 kW with fluorescents.

Recommendations/Energy Services Opportunities

All T-12 fluorescent lamps and magnetic ballast should be replaced with T-8 lamps and electronic ballast in the office, restrooms and common areas. Some of the spot lots in the office should be replaced with compact fluorescent spot lights. Replacing some of the stage lights with T-8 fluorescent lamps and electronic ballast should be investigated.

Links to Related Topics

Multi-Use Complexes
Full Service Hotels
Motels (sleeping only)
Convention Centers
Casinos
Sports Arenas
Concert Halls
Movie Theaters