How often does a frost free freezer normally defrost?

[ericmark]

I have been monitoring the chest freezer, for some time, and thought time I swapped the monitoring unit to the upright inverter drive freezer, and compare the two, not long enough yet to see average use really, but I expected to see a peak where the defrost elements have cut in, seem to remember around 160 watts, so would have expected it to show plainly, but been nearly 24 hours or maybe more, and no sign of the defrost cycle.

 

[SFK]

I presumed (and I stress the presumed) that they are 'frost free' because they de-humidify the air in the freezer (and do not actually defrost).

 

[foxhole]

They are fitted with fans to move air to rear where it condenses on cool back plate (before it can accumulate )and drains to rear to be evaporated in a tray over the heat from the motor.

 

[ericmark]

They are fitted with fans to move air to rear where it condenses on cool back plate (before it can accumulate )and drains to rear to be evaporated in a tray over the heat from the motor.

I realise that, what seems odd, is when, I was as said monitoring the chest freezer, then swapped to upright freezer, there is on auto defrost on the chest freezer, so the upright even without opening the door, uses more power as to what the chest freezer uses. However, it uses less floor space, and easier to access the food, I suppose we could have baskets in the chest freezer, but it doesn't.

So I look at the monitor and bottom left humps shows the defrost heater is being deployed, however not at a regular delay time. The bottom right covers 24 hours, and sometimes it seems to defrost twice in that time, and others not at all, at first I thought maybe defrost was not working.

The top right shows the cycle time, on/off, this was also surprising, although the mark/space ratio is about the same as the chest freezer, the chest will run three times an hour, where the upright only runs twice an hour.

I would say the chest uses an average of 25 watts, where the upright and average of 35 watts, they are around the same size, but upright cost a heck of a sight more, having inverter drive etc. So I had expected them to be on par with each other.

 

[Iwilldoit]

All the tec stuff is over my head but could it be that you are storing different products in one as compared to the other. Making it come on more often.
I can only think of ice, we have a frost free fridge freezer and notice that if we make our own ice in a tray and do not uses it then eventually it disappears - slowly evaporating away sucked dry by the freezer.

 

[ericmark]

Now I know the defrost function is working, there is not really a problem, I had expected it to work at least once every 24 hours, but it seems that is not the case.

 

[dishman]

This might help. It's the third part of the video that really helped me work out the issues with mine.

He uses a data logger to monitor the defrost cycle too. So it might help as a reference for you.

 

[ericmark]

Thank-you and interesting video, seems there is not a set time, but the software works out when required, so seems my unit is working as expected. It would seem mine has just completed the defrost cycle. Or is just about to start one.

 

[Justin Passing]

We had a Fr FR FR which had a thermostat to trigger the defrost cycle, every several days. When some ice accumulated the temp rose a very little. The fan's air flow sublimed the ice.
It kept blocking up...!