Where does defrost heat go when Fan is on?
The fans blow the moist residual defrost heat through the refrigerated space and through the evaporator coil while the system is in refrigeration. This puts the system, thus the compressor, under an extremely high load from high suction pressures. The compressor will see high suction pressures with dense vapors coming to its cylinders.
Is it normal for an air conditioner to defrost?
In a nutshell Defrost is normal and helps keep your air conditioning unit heating in Winter The indoor fan should stop (or turn to ultra low fan speed) during defrost Some settings may need to be changed to stop the fan on defrost Make sure the indoor fan setting is set to AUTO not constant
How often should a refrigeration fan be defrosted?
It should be set from 30 minutes up to an hour of off time during a period of low use, so as not to affect product temperature. Usually one defrost per 24-hour period is sufficient for this type of system. Figure 2. The defrost termination-fan delay stat is wired in series with the defrost termination solenoid and the evaporator fans.
Why do I need to delay the fan on my evaporator?
This is an adjustable setting on most controls (Figure 4) that lets the evaporator coil prechill itself and get rid of some of the defrost heat still in the coil. Delaying the fans prevents the suction pressure from getting too high after defrost and subsequently overloading the compressor.
In a nutshell Defrost is normal and helps keep your air conditioning unit heating in Winter The indoor fan should stop (or turn to ultra low fan speed) during defrost Some settings may need to be changed to stop the fan on defrost Make sure the indoor fan setting is set to AUTO not constant
When to turn off evaporator fans after defrosting?
After the evaporator is defrosted, the evaporator fans may need to remain off until any residual defrost condensate on the coil surface refreezes. This prevents the residue from blowing off the coil and onto the product.
How does a fan delay work in a refrigeration system?
A typical fan delay is set to turn on the fans at a temperature setting below freezing, thus ensuring that no water is blown from the coil onto the floor or product. You can keep this temperature fan delay control separate from the defrost termination temperature control, or combine it into one control.
What should the defrost temperature be in a refrigerator?
in the refrigerator is one of the most important factors to be considered in the design of a defrost system. Ice cream display cases must operate with a fixture temperature between –10°F and –20°F. The refrigerant evaporates at a temperature of approximately –40°F under these conditions.