Question:

What is the difference between a consumer brand refrigerator and a Commercial UL Listed refrigerator such as Marvel's?

Answer:

There are many differences to consider when comparing a refrigerator intended for residential use to a commercial or laboratory refrigerator. In household refrigeration models, maintaining an exact temperature is not critical and models are subject to energy consumption standards. Mechanical systems and thermostats are designed for optimum electrical efficiency, often at the expense of cooling performance under heavy use conditions.

In commercial refrigeration models, cooling performance is most important. Maintaining critical temperatures for stored commodities under heavy use conditions is a requirement. For this reason, energy consumption standards do not apply to commercial models which feature larger, more powerful mechanical systems and more sensitive controls. These features are required to maintain critical storage temperatures under conditions of frequent door opening, and to quickly cool large volumes of warm commodities when they are placed in the refrigerator.

The mechanical system must be designed to meet these requirements. Marvel refrigerators feature a 461 BTU compressor that is matched with a suitable evaporator and sealed unit bearing fan motor to ensure rapid temperature pull down upon startup and after frequent door openings.

Due to more vigourous usage and the potentially enormous cost of a fire in a hospital, laboratory, or other commercial establishment, commercial rated products are constructed to a much more stringent fire safety standard. The mechanical and electrical compartments must be constructed with steel sides, tops and bottoms to prevent any potential sparks generated by a mechanical or electrical failure from reaching flammable wall or flooring materials surrounding or beneath the unit.

The mechanical and electrical compartments of household refrigerators are often open in the bottom and rear or are enclosed by only cardboard or plastic materials.

On commercial refrigerators, the electrical power cord contains two layers of insulation for added protection against damage, electrical short, or shock. The hospital approved plug can be visually inspected to ensure the integrity of the ground wire.

Consumer refrigerator power cords are light weight, contain only a single layer of insulation, and cannot be visually inspected to determine ground status of the unit.

Marvel Scientific refrigerators are built with commercial rated wire shelves. This decreases the opportunity for temperature stratification within the refrigerator that commonly occurs with glass shelves found in residential refrigerators.

Marvel Scientific refrigerators are covered by a five-year limited warranty. Consumer refrigerator warranties do not apply when residential refrigerators are utilized in commercial settings.

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Please explain the difference between Hazardous Location and Flammable Material Storage refrigerators.

A Hazardous Location refrigerator must be hard wire connected to an appropriately rated electrical source. Hazardous location units are listed by UL for use in Class 1, Group C and D applications. The specially designed mechanical system has all electrical components enclosed in a precisison machined housing to prevent sparks from igniting explosive vapors in the environment.

A Flammable Material Storage refrigerator is listed by UL File SA7488 (N) and meets National Fire Protection Agency Standard 99. The Flammable Material Storage refrigerator features a double insulated power cord with three-prong plug. The specially designed mechanical system is constructed so that all electrical components inside the refrigerator are enclosed to prevent sparks from igniting flammable vapors which may be present in the interior of the cabinet or which may spill out of the cabinet upon door openings.

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Does Marvel Scientific offer an explosion proof refrigerator?

Yes, Marvel refers to refrigeration that is able to be located in a potentially explosive atmoshpere as Hazardous Location Refrigeration.

Please explain auto cycle defrost.

An auto cycle defrost system is the least complex and yet most effective defrost system available in an all-refrigerator model. Cycle defrost models contain a special thermostat which senses the evaporator plate temperature. At the completion of each compressor run cycle, the thermostat opens and turns off the compressor. The thermostat will not close again to initiate the next compressor run cycle until the evaporator plate reaches a preset temperature above freezing, typically 38 degrees F for Marvel refrigerators.

During the evaporator warm-up period, the frost which has accumulated during the previous compressor run cycle melts and becomes water droplets.

These water droplets run down the surface of the evaporator to the drip tray, which carries them to the drain tube.

The drain tube discharges the water droplets into the evaporation pan located in the mechanical assembly under the refrigerated compartment. There, the compressor heat and condenser air flow are used to evaporate the moisture.

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Are Marvel Scientific refrigerators available for export?

Yes, Marvel General Purpose undercounter refrigerators are available in 230V/50H 1P electrical configurations to meet many export electrical requirements. Always verify the power requirements at the intended installation location prior to ordering.

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How do I obtain service for a Marvel Scientific refrigerator?

In the event you require service on a Marvel Scientific refrigerator, please call 800-428-6644. Marvel Scientific has a national network of service agencies that are available to perform service when necessary. Please have your model number and serial number available when you call, to expedite your service call.

Where is the thermostat control knob located on undercounter refrigerators?