NuAire Ultra-Low Temperature Laboratory Freezers

Design and Materials

The Exterior shell and interior walls are constructed of heavy-gauge galvanized steel which conducts temperature more efficiently than stainless steel. This creates less stress on compressors making them run cooler and last longer than competitive cabinets.

Heavy-duty, easy-to-roll casters allow the freezers to be easily moved. Adjustable feet serve to adjust the overall height of the freezer and allow the freezer to be evenly leveled. The exterior insulated door has heavy-gauge galvanized steel construction with a baked-on-acrylic cool gray finish. The upright freezer door incorporates an anti-spring mechanism to protect the door from damage insuring a continuous positive seal. The chest freezers have an easy-open, easy-close countered balance lid. All models have a key lock for product security.

CFC-Free Polyurethane Insulation

Special foamed-in-place polyurethane insulation has been designed to withstand extremely low temperatures. The insulation used is two layers of rigid, dense polyurethane. The out layer and inner layer form a double insulated wall that is over 5 inches (135 mm) thick. This design prevents the insulation from distortion or cracking due to temperature differences inside and outside the chamber.

Performance and Product Protection

Special V-groove gaskets provide a positive seal, insuring efficient performance and product protection. The upright freezers use three gaskets for maximum sealing power -- the solid inner doors, the inner chamber, and the outer door. The chest freezers also use V-groove silicone gaskets for the inner chamber as well as extruded polystyrene sub-lids and an outer magnetic door gasket.

Specially Designed Compressors and Cascade Refrigeration Systems

A highly efficient, exclusive compressor has been specially developed and incorporated into each NuAire freezer. Each compressor is designed to be a powerful low-noise system that will deliver dependable, stable cooling. Each model is engineered to achieve optimum balance to maximize life expectancy and cooling efficiency.

The low stage compressor cycles off when the setpoint temperature is reached. This feature extends compressor life, protects the thermal overload system, decreases noise levels, and reduces power consumption. The high stage compressor runs continuously.

An oil separator effectively separates the lubricant oil from refrigerant. Lubricant oil is essential to prevent damage to the compressor. However, when lubricant oil circulates in the refrigeration circuit, logging (sludge build-up) of the refrigeration system results and service will be required. "Oil logging" is also prevented by the use of a built-in timer which cycles the low stage compressor off every 24 hours for 5 minutes allowing the capillary tubing to warm up and melt any ice crystals that may have formed within the system.

Reliability for long-term preservation has been improved by having all the copper refrigerant lines welded, not soldered. This exclusive refrigeration design virtually eliminates gas leaks and provides a very stable Ultra Low temperature environment.

Uniform Temperature Stability

The freezer's interior temperature maintains very stable refrigeration down to -85°C (-120°F), at an ambient temperature of 32°C (90°F). Temperature uniformity is the result of a new innovative freezer design. These features all combine to give the NuAire freezer uniform temperature stability:

• Properly sized compressors
• choice of CFC-free refrigerant
• synthetic lubricant
• locating the internally mounted platinum resistance temperature sensor so that the digital thermometer displays the temperature of the center part of the freezing compartment
• positioning the copper refrigerant line to deliver more cooling capacity to those areas of the freezer that need additional cooling capacity.

Extremely Quiet Operation

NuAire Ultra Low Freezers operate at dBA levels far below any competitive brand. Normal operation is less than 60 dBA at an ambient of 55 dBA. Hearing is believing, without special sound deadening material Ultra Low freezers from NuAire are the quietest.

Microprocessor Control Precision

The integrated main microprocessor control board performs all primary functions accurately and reliably, including main temperature control, temperature set point, actual temperature, and various alarm systems. Freezer running parameters are displayed with bright red LED's and user input is easily accomplished via digit shift, figure shift and entry touch pads. The control panel keypad gives the operator maximum flexibility and simplicity in programming and complete display of information in one convenient location.

Automatic Alarm System Dependability

A high temperature warning system activates both audible and visual alarms when the temperature deviates 10°C from the set point or in case of power failure, and with interruption or irregular fluctuation of temperature. The system is equipped with a remote alarm contact for external monitoring and a continuous charge battery back-up provides control panel alarm function even if power is lost.

The freezer also has a Filter Check Lamp. A red LED on the control panel will automatically illuminates when the condenser filter is clogged. The condenser filter can be easily removed, cleaned and replaced.

Inventory Systems

The large capacity upright freezers employ stainless steel movable shelving which allows the user the opportunity to maintain better space utilization. Both the chest and upright freezers hold a variety of inventory racks to make the most efficient use of available storage space providing accurate control of stored product.

Low Power Consumption

NuAire's Ultra Low freezers are designed to be energy efficient with:

• Quick pull-down and recovery time
• Energy efficient compressors
• Effective cooling distribution
• Electronic microprocessor control precision

ROHS Compliance

NuAire Ultra-Low Temperature Laboratory freezers are ROHS Compliant, making them an effective participant in keeping our environment clean and CFC-free!