You'd be surprised how efficient they are; give this article a read:

https://www.greenbuildingadvisor.com/article/choosing-an-ene...

What most people consider "old" for a fridge is probably late 70s/early 80s, and those ones did use a lot of power for some reason or other (usually defrost heaters); but the ones much older than that used far less.

I'm restoring it, which does mean rewiring and putting better insulation in the cabinet, but other than that the refrigeration system itself is still original and sealed (that's why they can last almost indefinitely.) If anything, it would likely make it even more efficient.

I'd be interested in a quantitative analysis of the power usage. Are you documenting the refurb anywhere?

https://www.thegeoexchange.org/fridge-power-consumption/inde... - shows a saving of two-thirds by replacing a 20yo fridge with a mid-range model (they say they could have saved about 80% power use with a more expensive model).

I'm not, but someone on YouTube has taken the time to document restoring one of similar vintage:

https://www.youtube.com/watch?v=k_ysVqppaN0

The article you posted shows they went from 1300kWh/yr to 412kWh/yr. Amusing that it says "Some use as little as 255 kwh/year" when the article I posted mentions 244kWh/yr for the 30s Monitor-Top. (Mine is a "flat top" but has a very similar refrigeration system.) Like I said, average power consumption went up after the late 60s/early 70s, but before that they used less.

The compressor in mine draws <100W when running. A quick calculation shows that if it was running 24/7 that would be almost 900kWh/yr, but it definitely won't be running that much --- duty cycles I've found for these old ones vary from 15-20%, giving around 200kWh/yr, still very good. How often you open it and/or put warm things in probably has a higher impact on total power consumption than anything else.

Thanks for that.

This is extremely surprising, no. Motor/compressor/refrigerant/insulation design have all improved considerably.

Any insight there?

Usage patterns clearly have an impact, but I doubt they change much for a particular family across models -- some models have little doors for heavy use items to reduce air exchange, compartments probably make a big difference ('glass' shelves instead of wire).

Interesting. /beardStroke

Apart from improved insulation I don't think there's been much in the way of improvements since the late 30s --- if you look at the hermetic systems, they haven't changed much in decades.

In fact, the newer "environmentally friendly" refrigerants are less efficient than CFCs... so it's sort of a tradeoff between risking more ozone depletion when they leak, or putting more CO2 into the atmosphere from the higher power consumption...