RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,565
Issue with using a freezer for refrig is the freezer may not run a defrost cycle often enough.
The more ice buildup on cooling evaporator coils the less air flow across cooling coils so it runs longer to cool down air. In a humid environment, >70% relative humidity, this can have a significant impact in less than 24 hours without defrosting.
If you use a temp controller or timer to cut total AC power to freezer you may totally defeat its defrost timer by resetting it every time power is removed. Some units trigger a defrost cycle every time they initially get AC power. This will consume more power if total AC power cut is used to control temperature.
Refrig's normally get opened more often allowing more humidity in.
A freezer with top opening door reduces the amount of outside air exchanged when opened.
Many freezers use a positive temp coefficient thermistor to control the engagement of starter capacitor to compressor. They need at least a 20-30 minute off time to allow thermistor to cool down to reenable start capacitor.
If you attempt restart of compressor before thermistor resistance has dropped back down in resistance you will not get starting boost of start capacitor. Compressor will have longer starting surge current or may even not start up resulting in locked rotor until over temp switch protection disables power to compressor. If this happens it can take a couple of hours before compressor cools down enough to reset over temp cutout switch.
The more ice buildup on cooling evaporator coils the less air flow across cooling coils so it runs longer to cool down air. In a humid environment, >70% relative humidity, this can have a significant impact in less than 24 hours without defrosting.
If you use a temp controller or timer to cut total AC power to freezer you may totally defeat its defrost timer by resetting it every time power is removed. Some units trigger a defrost cycle every time they initially get AC power. This will consume more power if total AC power cut is used to control temperature.
Refrig's normally get opened more often allowing more humidity in.
A freezer with top opening door reduces the amount of outside air exchanged when opened.
Many freezers use a positive temp coefficient thermistor to control the engagement of starter capacitor to compressor. They need at least a 20-30 minute off time to allow thermistor to cool down to reenable start capacitor.
If you attempt restart of compressor before thermistor resistance has dropped back down in resistance you will not get starting boost of start capacitor. Compressor will have longer starting surge current or may even not start up resulting in locked rotor until over temp switch protection disables power to compressor. If this happens it can take a couple of hours before compressor cools down enough to reset over temp cutout switch.
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