Refrigerators and freezers

Rigid polyurethane foams used in refrigerators and freezers - Alternatives include hydrocarbons (pentane) and HCFC-141b long-term alternatives include HFCs (134a, -245, -356, -365). Vacuum panels may be used in the future. 

Control Systems Heat and Heating Heat Pumps Insulation Refrigerators and Freezers Water Heating. 

See also Carnot, Nicolas Leonard Sadi Climatic Effects Engines Matter and Energy Nuclear Energy Nuclear Fission Refrigerators and Freezers Thermal Energy. 

Additionally, as a response to rising energy prices and uncertainty of supply, several states adopted appliance efficiency standards. At the federal level, the National Appliance Energy Consei vation Act of 1987 established the first national standards for refrigerators and freezers, furnaces, air conditioners, and other appliances. The Energy Policy Act of 1992 added national standards for incandescent and fluorescent lights, small electric motors, office equipment, and plumbing products. 

More advanced insulations are also under development. These insulations, sometimes called superinsulations, have R that exceed 20 fthh-°F/Btu-m. This can be accomplished with encapsulated fine powders in an evacuated space. Superinsulations have been used commercially in the walls of refrigerators and freezers. The encapsulating film, which is usually plastic film, metallized film, or a combination, provides a barrier to the inward diffusion of air and water that would result in loss of the vacuum. The effective life of such insulations depends on the effectiveness of the encapsulating material. A number of powders, including silica, milled perlite, and calcium silicate powder, have been used as filler in evacuated superinsulations. In general, the smaller the particle size, the more effective and durable the insulation packet. Evacuated multilayer reflective insulations have been used in space applications in past years. 

See also Electricity Energy Intensity Trends Heat and Heating Heat Transfer Magnetism and Magnets Molecular Energy Refrigerators and Freezers Thermal Energy. 

Bansal, P. K., and Kruger, R. (1995), Test Standards for Household Refrigerators and Freezers I Preliminary Comparison. InternadonsI Journal of Refrigeratinn lS(l) 4-20... 

Consulting Engineer, Isle oj Palms, SC Refrigerators and Freezers... 

Temperature changes in layered composites lead to shape distortion via spatial differences in material properties. Our original interest in the phenomenon was motivated by quality control during the manufacturing of the boxes for refrigerators and freezers. These boxes are made from a steel sheet as an outside layer, a plastic liner and urethane foam in the middle. In our case, the liner was made from... 

Similarly, the use of ultra-low viscosity lubricants in compressors for refrigerators and freezers can cut energy consumption by 10%. With refrigerators, freezers and air-conditioning units representing somewhere between 5 and 10% of the UK s total electricity consumption, this is a very interesting commercial opportimity. ... 

European market in refrigerators and freezers, and are also used for packaging fats. Here, too, development work is still in progress. 

In addition, the CBER controls the approval of human tissue for transplantation, blood and blood products, and devices related to blood products. These devices include automated cell separators, empty plastic containers, and blood storage refrigerators and freezers. 

Figure 6.20 Refrigerator and freezer with dual evaporator.

All equipment, including balances and hoods, nust be regularly maintained and so documented. Minimally, hoods should be checked on a yearly schedule. Dow Chemical Company uses the label shown in Figure 4 to document hood maintenance checks. Refrigerators and freezers nust have a temperature recorder of some type or be manually checked and the temperatures recorded. This covers the major GLP related items in the analytical laboratory. 

Use only explosion-proof or intrinsically safe refrigerators and freezers for storing flammable liquids. 

---