Food-Service-Manual-for-Health-Care-Institutions

Food Service Manual for Health Care Institutions
710
The requirements for walk-in-freezers are similar to those for walk-in coolers, except that
more insulation is needed. Freezer units installed with the door opening into a walk-in cooler
eliminate storage space on one wall of the cooler, and access to the freezer can be inconvenient.
All walk-in coolers and freezers should be equipped with recording temperature thermometers
that can be easily read by food service personnel. Alarms should be installed in the engineering
department that alert engineering staff to a problem.
Self-Contained Refrigerators and Freezers
In self-contained units, the refrigeration system is mounted at the top or bottom. Bottommounted
models reduce the amount of convenient space available. A compressor, condenser,
and evaporator of the right size are needed for uniform temperature control regardless of the
load. Foamed-in-place or froth-type urethane insulation of 21 ⁄2 inches or more thickness is recommended
for walls, ceilings, and doors. A one-piece, durable, seamless lining in the interior
cabinet is needed to allow for easy cleaning. Exterior finishes vary among manufacturers; vinyl
in a choice of colors, stainless steel, and other durable metals are used.
Refrigerators and storage freezers are designed as reach-in or pass-through and roll-in or
roll-through units, which are convenient in areas between production and service. Solid or glass
doors may be hinged on the right or left. One-piece molded door gaskets that provide a positive
seal are recommended to conserve energy. Full- and half-door models with self-closing and
safety-stop features are available. A system for locking all doors is needed for security. An exterior
dial thermometer and audiovisual temperature alarm should be installed in all units.
Adjustable legs facilitate leveling of reach-in and pass-through cabinets. Single units may be
equipped with casters for mobility. Other design options include provisions for interchangeable
interiors that accommodate adjustable rustproof wire shelving, tray or pan slides, roll-out
shelves and drawers, and flush-with-floor models for mobile carts and food service racks.
Quick-Chill and Freezing Systems
Refrigeration systems capable of chilling precooked foods to 41°F (5°C) in less than four hours
are available in one- or two-section roll-in units. Rapid chilling is accomplished by circulating
fans installed within the cabinet. High-velocity air, forced horizontally over the surfaces of the
food product, eliminates the formation of layers of warm air that can slow heat transfer.
Self-contained or remote quick-chill models can be purchased. Cabinet finishes, insulation
materials and thickness, door gaskets, hinges, locks, and other features are similar to those
found in conventional storage refrigerators. One model automatically reverts to a 38°F (3°C)
storage refrigerator at the end of the quick-chilling process. Standard equipment includes a chill
timer and several temperature probes. An external probe selector switch, temperature indicator,
and audiovisual alarms should be requested.
Foods can be frozen by blast or cryogenic freezing systems. Self-contained roll-in models
or large chambers with a conveyor belt are available. In blast freezing, the product’s temperature
is lowered to 0°F (–18°C) or lower by high-velocity circulating air and a mechanical refrigeration
system. In cryogenic freezing, liquid nitrogen or carbon dioxide in a liquid or gaseous
state and moving air quickly remove heat from the product. The design and construction features
of the cabinet are similar to those of other refrigeration systems. Comparisons of the
capabilities of the mechanical parts used to lower temperatures and the time required in various
models should be made before selecting a freezer.
Tempering Refrigerators
Food service departments that use mostly frozen foods should consider specialized equipment
for tempering (thawing) foods rapidly. Conventional refrigeration systems require a great deal of
time for this process. Individual units are designed to thaw foods rapidly by using high-velocity
airflow and a system of heating and refrigeration. Products are safe throughout the process
because the cabinet air temperature never exceeds 45°F (7°C). When the tempering process is completed,
the cabinet may be operated as a conventional refrigerator. Conventional refrigerator