Normal Amount of Frost on Evaporator

[Chetlaham]

How much frost build up is normal in between defrost cycles? I am guessing this is good but want to double check.

 

[qsd-dan]

That's normal. When it completely ices over, start worrying.

I had a 2005 GE SXS that had a couple of those glass tube defroster failures plus a control board failure, several ice cube auger replacements (freakin plastic auger??!?!), water valve failure, and water filter head unit. I spent way too much time pulling everything out and defrosting those coils with a hair blow dryer.

 

[Chetlaham]

That's normal. When it completely ices over, start worrying.

I had a 2005 GE SXS that had a couple of those glass tube defroster failures plus a control board failure, several ice cube auger replacements (freakin plastic auger??!?!), water valve failure, and water filter head unit. I spent way too much time pulling everything out and defrosting those coils with a hair blow dryer.

I'll never understand why GE put glass tube defrosters in their fridges. Just stupid. A good quality calrod heater would be ideal.

Speaking of control board another thing I want to see is side by side fridges going back to a plastic damper and EM defrost timer.


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On thing which I have theorized about is a horse shoe shaped evaporator with a 100 watt calrod heating element intimately in parallel with the evporator and electrically in parallel with cold control thermostat coupled with an over sized sealed system.

In theory every time the thermostat is satisfied the serpentine heater would come on gradually melting the ice during the off period from the evaporator until the thermostat closes again.

GE did this very successfully in the fresh food section of their manual top mounted freezer defrost refrigerators.

Although two potential down sides to doing it that way in the freezer section could pop: If the door was repeatedly opened the compressor run time would go way up and off time way down- to the point the evaporator could become excessively frosted. Once excessively frosted, the thermostat may never open causing the fridge to run indefinitely and frost to keep building up to the point the unit can't cool.

Another down side would be if the compressor switched on while the frost was only partially melted would result in the water droplets freezing leading to the evaporator gradually building up ice chunks.

I am sure if it was that successful it would have been done by now- elegant to eliminate a possible failure point- but I guess the defrost timer, high wattage heater and defrost termination stat might be better after all.

I'd still like to try it out in a lab if I could to see just how practical the idea could be.

 

[Chetlaham]

That's normal. When it completely ices over, start worrying.

I had a 2005 GE SXS that had a couple of those glass tube defroster failures plus a control board failure, several ice cube auger replacements (freakin plastic auger??!?!), water valve failure, and water filter head unit. I spent way too much time pulling everything out and defrosting those coils with a hair blow dryer.

Here it is, one of the most beautiful and elegant manual defrost refrigerators ever created by GE. IIRC 13.5 ounces of R12 refrigerant according to the interior label but the tech sheet has it as 10.5 for some reason. Perhaps one charge for the 13 cubic foot units and another for the 15 cubic foot units. No evaporator fan and no condenser fan. Full width condenser coils on the back rarely needed frequent cleaning.

These used a concept known as a "cycle defrost" where a serpentine heater defrosts the fresh food evaporator via an electrically parallel connection with the main thermostat.

These were exceptionally simple and reliable fridges and I would gladly take a NOS in box unit. The only exception unfortunately was that the aluminum (?) evaporator plate was exposed on the bottom, back and top of the freezer. That lead to the evap taking the full force of people dropping and shoving ice packs, containers and boxes on top of it. Made much worse by the fact renters would try and remove the excessive freezer ice build up via ice picks, spatulas, spoons and putty knives. Puncturing a hole in the evaporator tubing making the unit impractical to repair. Nearly every single unit in the scrap pile had a leaky evaporator.

Had GE put the evaporator behind plastic as is done with most modern manual defrost compact fridges the whole failure point would have been sparred and these fridges might still be in service today.













I'd love to see a 22.5 cubic foot side by side version of these with a concealed evap but of course but I doubt anyone would ever attempt that today.

Of note, tech sheets that came out of smoker friendly units were always substantially more yellowed than those that came out of none smoker units. Even the smell of the cigarettes would linger for years on the tech sheets that came out of the smoker units. Tech sheets also gave away units where there was ever a toiler overflow or water leak. Curry, fried cooking, ect also indicated. If only these pieces of paper could talk, LOL.

 

[Chetlaham]

And oh, to add, the auxiliary condenser was underneath a drip tray pan which caught defrost water from the fresh food compartment evaporator.

Assuming the serpentine heater has a steady resistance between being ohmed out and when operating, 1890 ohms at 120 volts dissipates about 7.6 watts of power.