High latent heat of vaporization and specific heat. Critical pressure and temperature well above the maximum operating pressure and temperature limits. Low value of specific volume.

The desirable properties of a refrigerant are as follows: Large conductivity to reduce size of condenser and evaporator. Low freezing point such that there is no blockage during flow through evaporator. Non corrosive to metal and inert so as to not react with other materials and commodities of the refrigeration system.

It should be non-explosive and non-inflammable. It should be relatively cheap and easy to obtain. It should not be poisonous and should not give discomfort where gas leaks to the outer air. It should be of such nature that gas leaks are easily located by “smoke tests ” or similar methods.

As ethylene has flammable characters it is not commonly used as a refrigerant.

There are two key disadvantages to using ammonia as a refrigerant: It is not compatible with copper, so it cannot be used in any system with copper pipes. Ammonia is poisonous in high concentrations.

Refrigeration has many applications, including household refrigerators, industrial freezers, cryogenics, and air conditioning. Heat pumps may use the heat output of the refrigeration process, and also may be designed to be reversible, but are otherwise similar to air conditioning units.

about 30 minutes

Instead of slow and gradual cycles, short-cycling is what happens when the furnace shuts on and off rapidly. This is bad for several reasons: Your home takes forever to heat up: Since the furnace can’t go through a full cycle, it takes much longer for the home to reach your desired temperature.

Your fridge has to work to keep your food at the required temperature. Typically, a refrigerator should run for about 4 to 8 hours before it shuts off and goes into a defrost cycle.

approximately 25 to 45 minutes

Complete a visual inspection of the ice buildup in the freezer. If the ice appears wet or slushy, it indicates the refrigerator is in defrost mode.

Well, the truth is, every manual-defrost fridge freezer is different and when it needs defrosting will depend on how you use it. As a general idea, we would recommend defrosting the whole appliance at least once or twice a year. Or, when you can see around a quarter of an inch of ice build-up on the walls.

This moisture becomes frost inside your appliance, which builds up over time. If your freezer doesn’t have an auto defrost option, this frost can become ice that covers interior air vents and temperature sensors. This can cause your freezer to work overtime, wasting energy and exacerbating ice buildup.

If the refrigerator does not defrost, the defrost thermostat might be defective. In a defrost system, the defrost heater turns on several times in a day to melt away the frost developed on the evaporator coil. This defrost heater is connected to a defrost thermostat.