frost top construction ???

[herefishy]

Tom Richardson,

In re: to superheat, read this:

http://www.hvacwebtech.com/trouble.htm

or this:

http://www.refimax.com/docs/therm_exp_valve.htm



Measure your suction line temperature exiting the evaporator (or cold plate).

Measure your suction pressure.

Refer to the "satuaration" temperature of your pressure reading on your pressure/temperature chart.

Subtract your saturation temperature of the refrigerant pressure (chart temperature reading) from your suction line temperature and the result is the superheat (the degrees above the boiling point that the refrigerant is at as it leaves the heat exchange device, evaporator or cold plate).

For medium temp, typically you want to be at about 7-9degrees, but in your close-coupled system a little bit more is not bad. You can adjust the responsiveness of your cold control scenario by relocated the cold control sensing location. For more positive reaction (defrost) you would locate the sensing location closer to the inlet of the evaporator.