truly silent bar fridges?

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richms

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#154112 18-Oct-2014 09:51

Last one I tried was fine for its fridge noises but had some loud relay or something to turn the compressor on and off which has a loud click - louder than a sensor light relay. and the compressor started with a thump.

Do these fancy looking ones for "wine bottles" do a better job at not being noisy?

Richard rich.ms

Fred99

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#1157349 18-Oct-2014 10:25

Electrolux (or equivalent) "absorption" fridges don't have compressors and are practically silent. Some hotels use them.

I guess that the loud "click" of a relay could be avoided if you wanted to rip into the internal electrical circuits, and replace the electro-mechanical relay with an electronic relay (SSR), but you'd need to know what you were doing.

I guess some of the small "chillers" use peltier device, which isn't very energy efficient, but if it's a maximum draw of ~ 50 watts for a small chiller, that might be acceptable.

richms

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#1157354 18-Oct-2014 10:32

Those cheap chillers usually have a fan worse than any pc fan outside of a 2u server.

Just thought that the pricey wine ones might have inverter drive so they are quiet. One said it was vibration free which gave me hope but all the sales people say their crap is quiet even the ones selling $149 budget ones.

Richard rich.ms

Niel

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#1157442 18-Oct-2014 13:15

Absorption fridges that work the same as 3-way camping fridges (LPG, mains or 12V) use ammonia to absorb energy out of the internals and release it to the surroundings. The process is maintained by putting a small amount of heat into it. Funny how putting in heat can produce cooling, but it works as the heat creates circulation rather than heating it up. Not very efficient, but they are silent apart from maybe sometimes you might briefly hear a bubble but unlikely especially when the element is at the back and under a counter. Perhaps the bubble is only at the initial stages, because to kick-start a camping fridge you rotate it to get the ammonia in the correct place and that could introduce some bubbles.

An option could be a duel mode fridge (mains or LPG) which would be more suitable than a camping fridge. It does cost a bit. Or modify an LPG fridge to use a mains heater instead, can't be too hard. Could even use a mains heating element but supply it with DC which is easy/safe to DIY. Our 40L camping fridge uses 80W. Rough calculation suggests a 2000W mains heating element supplied with 50V DC would draw 1.7A and dissipate 80W. Modern dishwashers have nice compact in-line heaters.

Another option is to replace the cheap rubbish fan in a Peltier cooler to a silent fan. But Peltiers are something like 30% efficient (I think). Or make your own Peltier cooler with a massive passive heat sink.

You can never have enough Volvos!

richms

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#1157461 18-Oct-2014 13:27

Both reasonable ideas but I prefer the idea of going to a shop or just ordering a fridge.

Richard rich.ms

Aredwood

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#1157886 19-Oct-2014 14:26

Due to energy efficiency rules, mains only asorbtion fridges cant be sold here. Due to their inefficiency. So looks like you would have to buy a 3 way fridge and just use it on mains only.

Sidestep

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#1157916 19-Oct-2014 15:55

They're inefficient. But - they are pretty much silent, and last forever.

We have a "consul" propane fridge/freezer. Built in Brazil by Electrolux, LPG /mains.
Neglected for maybe 25 years now, in an old cabin on the open coast.

We swap LPG tanks over once a year, tanks never empty, we replace them due to corrosion.
Stores an emergency beer supply in case mechanical issues or tides trap us out there.

Guess one day the coils will corrode through, or the doors fall off..

Peppery

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#1157920 19-Oct-2014 16:06

How much noise is acceptable? We have one from Red Bull. It has a very slight hum but no loud compressor switches.

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richms

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#1157931 19-Oct-2014 16:17

Well ideally no noise at all, it seems to be the loudest one on the generic chinese one labeled by a retailer is the relay/thermostat switching, and the whole thing thumping as it starts or stops. When running it is fine - barely anything sitting right by it and cant hear across the bedroom at all.

Might try to put a timer on it so that its not running when I am trying to sleep.

Richard rich.ms