Very old fridge, but how old?

[Jan Zodiac]

I did some research on HC-12a, and it is illegal in EU for use in non hermetically closed systems.

There seems to be another drop in that is called RS24, which consists of 20% butan and 80% R134a. The small amount of butan means it is non flammable, and it also means that the oil, seals, etc. as used for R12, does not have to be replaced.

Refridgerants is quite a large topic, with a lot of research going on to develop newer and more efficient types. I read that ammonia is also being used, as it is very energy efficient.

I took some pictures of the compressor unit. Several components, valve, thermostat, filter, are Danfoss types. The compressor itself, only has a serial number, but no manufacturer ID, so it is most likely the company's own unit.

I found some information on the Nordisk Køleteknik A/S (directly translates into Nordic Cooling Technology LTD), and it was apparantly a large and old company, that made all sorts refridgeration units, mainly for industrial use.
They surely had production of compressors.

Jan

[SiriusHardware]

It was a big thing in the USA.

The opening sequence in the movie 'Indiana Jones And The Crystal Skull' even has a reference to the danger of playing about in old fridges, showing that the message must be quite well entrenched in the mindset / education of Americans especially.

[emeritus]

Odhams classic book "Radio television and electrical repairs" has a chapter on refrigeration that clearly relates to 1940's technology. Only belt-driven compressors are illustrated, although my copy of the third edition (1956) does makes a passing reference to the new sealed units. The refrigerants mentioned are sulphur dioxide, methyl chloride, and freon.

[Jan Zodiac]

So after a lot of searching around on the internet, I believe I have come a little closer to determine the age of the fridge.

The attached picture is one of the very few I found on "danish refridgerator history". This history is almost not covered at all. On the left in the picture, a fridge for ice blocks is shown, and in the middle an imported american Fridgidaire from the same era.

In the 30's almost all imports was seized, due to the global financial crisis, which led Danfoss to be founded. The founder began to manufacture valves, thermostats etc. because imports from the US had stopped.
The name Danfoss was not used as a brand name until 1946, which means my fridge can't be produced prior to that, although the design is very similar to the Frigidaire in the picture.

Both thermostat, filter and evaporator valve in my fridge has Danfoss as a brand name on them, so it is most likely a late 40's model.

I can't imagine it being from the 50's, because more modern looking types were already available. From 1946 Atlas started production of absorbtion types and it was a modern factory. I think the belt driven models were only a very small production, made by either local companies that ordered a kit consisting of the compressor unit and evaporator, or made as a side production at the larger companies that produced cooling systems for the industry.

To me it is an interesting piece of history, and I will check out if it is possible to get it restored and running.

Jan

[Joe_Lorenz]

For refrigerant replacement you might want to google "Easy Klima". I do not know what exact formula they actually sell, but it does the job.

And please let me put down two extra notes:

1. The compressor has got bearings and pistons that need to be lubricated. Ancient oil may wish to be replaced, me thinks. As well as the bearings of the electrical motor need to be serviced.
2. Last but not least the insulation of wires may have become brittle, so please check them all! Often I find 1930's power cords in a condition unacceptable for use.

Regards, Joe

[CambridgeWorks]

Without specialist leak detectors, a leak is usually seen as a trace of oil around the area.
In your case, check carefully for darker stain areas around all parts of the compressoor, especially the pulley shaft seal. If wet or very slight dripping it is a quite major leak in terms of refrigerant.
Also check around the expansion valve near the ice box.

Rob
More modern systems use special synthetic oils.

[Jan Zodiac]

Thanks

Yes I will definetely go over the complete system. As for leaks, nothing around the compressor itself, indicates any kind of oil coming out, but that does of course not indicate any gas leaks.

I'm sure I will have the oil changed, since it was probably never done.

The motor bearings are standard ball type bearings, and I will replace them, as well as the power cords (all are rubber). Strangely they haven't become brittle yet, but I will replace them for safety anyway.

Thanks for the advice on the Easy Klima website. I will have to do some research on how these old things are restored.

Jan

[emeritus]

The quality of old rubber cables varied enormously. I still have some lengths of the Pirelli rubber cable that I removed when rewiring our 1938-built house. It is still in excellent condition, even the red rubber that usually seems to deteriorate first. The rubber mains flex on the A3 Hornby-Dublo speed controller that dad must have bought around 1954 is likewise in good condition. Conversely, I have encountered house wiring in 1930's houses where the rubber insulation has crumbled away when disturbed, leaving bare copper conductors.