Regional shopping centers generally incorporate an enclosed heated and air-conditioned mall-developer, who may be an independent party, a financial institution, or one of the major tenants in the center, normally owns these centers.
The anchor store(s) (typically major department stores) - may be considered separately, although attached to the mall. The individual small stores are usually individually leased. Air-conditioning systems in the individually leased spaces are similar to those for retail stores. Most stores will be individually metered for utilities and each tenant will be responsible for the utilities.
The developer or owner provides the air-conditioning system for the enclosed mall. The mall system may use a central plant or unitary equipment. The owner generally requires that the individual tenant stores connect to a central plant system and includes charges for heating and cooling in the rent. Where unitary systems are used, the developer generally requires that the individual tenant install a unitary system of similar design. The standards established by the developer for typical heating and cooling systems may or may not be sufficient for the tenant's specific requirements. In some cases, the tenant may have to install a different sized system than originally planned by the developer.
Leasing arrangements may include provisions that have a detrimental effect on conservation (such as allowing excessive lighting and outdoor air or deleting requirements for economizer systems). The utility's representative should work with the designer to be fully aware of the lease requirements and work closely with leasing agents to guide these systems toward better energy efficiency and consider heat pumps, thermal storage, and other energy conservation technologies.
Most large shopping centers contain food court areas. Odor control, outdoor air requirements, kitchen exhaust, heat removal, and refrigeration equipment requires special considerations of these areas.
The physical arrangement and architectural design of shopping malls vary widely. Single level and smaller centers usually use unitary systems for a mall and tenant air conditioning; multilevel and larger centers usually use central plant systems.
The developer sets the design of the mall system and generally requires that similar systems be installed for tenant stores. A typical central system may distribute chilled air to the individual tenant stores and to the mall air-conditioning system and employ variable volume control and electric heating at the local use point. Some systems distribute both hot and chilled water.
All-air systems have also been used that distribute chilled or heated air to the individual tenant stores and to the mall air-conditioning system and employ variable volume control at the local use point. The central systems provide improved efficiency and better overall economics of operation. They also provide the basic components required for smoke control systems. Smoke management systems are required by many building codes.
Air distribution should be designed for each individual store. Depending on the store, the tenant may maintain either a negative or positive pressure relative to the mall for odor control. The mall's air distribution system typically maintains a slightly positive pressure relative to outdoors. Exterior entrances usually have vestibules with independent heating systems.
Energy Saving Recommendations
Energy services opportunities in shopping centers are similar to those used in department stores. Where a central chilled water system is installed, some shopping centers can successfully employ cooling tower heat exchanger economizers. Central plant systems for regional shopping centers typically have much lower operating costs than unitary systems. However, the initial cost of the central plant system is typically higher. Other opportunities include:
- Older inefficient cooling and heating systems should be investigated for upgrading or replacement, particularly if CFC refrigerants are used.
- Where demand and/or on-peak energy costs are high, investigate thermal storage.
- Add Economizer cycles if they are not installed or in use
- Upgrade antiquated or inappropriate control systems.
Typical System Water heating is not a major energy user with uses typically for hand washing and cleaning purposes, except for the food court. 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. Some malls may use central distribution systems with storage and constant recirculation where it is desirable to have hot water available continuously at the fixtures.
Energy Saving Recommendations
If existing systems are inefficient or inadequate, replace with modern efficient equipment. If a source of waste heat (i.e. tower water) is available, consider a water-to-water heat pump heater.
Most large shopping centers contain restaurants as well as food court areas. Their cooking needs should be handled as appropriate.
In a shopping mall, the relaxed atmosphere encourages browsing, with sales help available when needed.
Medium to high general lighting, 25 to 75 footcandles, is appropriately combined with accent lighting. The accent light level should be five times higher than the general lighting. Visual merchandising scenes may be highlighted.
A neutral color temperature, 3500k to 4100k and high color rendering, at least 75 CRI, encourages the customer to browse leisurely through a department. Maximum attention is directed onto the merchandise. Triphosphor fluorescent, incandescent, and color-improved high-pressure sodium and metal halide may all be appropriate. Usually, fluorescent recessed 2 X 4 fixtures or HID downlight fixtures will provide the general illumination.
Incandescent halogen line or low-voltage lamps in downlight or track fixtures are a good choice for accent lighting. Perimeter lighting of wall displays is important to add a spacious feel and to accent the merchandise. Fluorescent lamps behind a valence are most popular. Overlap the ends at least an inch to eliminate dark spots.
Energy Saving Recommendations
Appearance is much more important to a mall tenant than energy cost and in many cases is dictated by the home office or franchiser. However, T-12 lamps with magnetic ballast should be replaced with T-8 lamps with electronic ballast. Incandescent accent lights - usually spots - should be replaced with compact spots where acceptable effects can be maintained.