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SILENT FRIDGE: What would you advise?

Posted: Sat Nov 03, 2007 5:19 am
by maria_
Hello SPCR members,

I need an advice from you.

I have a studio flat, therefore I need to keep my fridge (refrigerator + freezer compartment) in the same room with my pc.

Now, my PC is fanless. Everything including the PSU is watercooled (passive), pump submerged. 0 db.

The problem I have is with my fridge. I have a 6 year old one and while it was quiet at the beginning, now it is noisier since compressor is getting old.

Therefore I bought a new Hitachi fridge Z-R320 (260 lts). Unfortunately, this is as loud as the old one it was supposed to replace. For now, I have closed all the holes around the fridge with towels and placed the fridge on noise dampening material. This effectively eliminates the noise problem but I am assuming the compressor will burn-out soon since there is very little fresh air entering the compressor area.

I am living in Middle East and I don't have a variety of brand options. I don't have the possibility to test a fridge either. When I ask about db levels, the sales person has no clue what I talk about.

What would you folks suggest for a quiet fridge? I need 200-250 lts capacity.

Thanks in advance for your time.

Maria


PS: I have been following your site for almost 5-6 years, keep up the good work.

Posted: Sat Nov 03, 2007 5:53 am
by Ralf Hutter
Moved to Off Topic.

Also, we've at a couple threads about fridges over the years. A quick search should turn them up, right here in the OT Forum..

Oh, and WELCOME TO SPCR!!!

Posted: Sat Nov 03, 2007 6:07 am
by Bluefront
Trying to determine how quiet these sorts of products are in a retail store is always difficult. The salesmen are no help, and the ambient noise levels are usually too high.

I'd suggest visiting all of your friends and relatives....and anybody else you can. Then listen to the units they have. Leave the door(s) open for a short time to get the compressors turned on. That might work best.

Posted: Sat Nov 03, 2007 6:23 am
by Das_Saunamies
I've yet to find a quiet fridge, they all make some noise when the compressor engages. There might be some that are quieter than others, but they'll likely be sold with the word "silent" plastered all over them. Easy to spot. :D

Best bet is insulation and good care. Some DIY with plywood and foam panels might be just the thing - then just keep it clean to improve cooling efficiency.

Posted: Sat Nov 03, 2007 6:27 am
by alleycat
I don't know if you have these where you are, but in remote locations with no electricity we use gas refrigerators which run on LPG. Also depends on whether you can get LPG bottles...

They are silent and efficient, however.

Posted: Sat Nov 03, 2007 6:46 am
by VanWaGuy
DON'T block all the airflow to the fridge in an attempt to make it quiet!

The fridge coils need air flow to get heat off of them. If you block too much air flow, you can burn out your new fridge quite quickly. (Not quite as fast as that AMD chip that I did not have the heatsink seated right, but that's another story.)

Check your users manual, but there are certainly areas that it is telling you to keep clear, and sadly, that will most probably be the same area the noise is coming from.

I think if you want a really quiet fridge, you start with a P180, a bunch of peltiers, and ... :)

Posted: Sat Nov 03, 2007 8:31 am
by MikeC
You could try to find out exactly where the noise is coming from. Here's a pretty good summary of things to look for.

It could be a fan, the compressor, or something touching the back of the fridge that's being vibrated.

If it's the compressor, there's probably not much you can do. AFAIK, in contains a sealed motor, and the motor is suspended inside with springs. If the springs are weak (which is what happens over time due to effects of gravity), and the motor touches the casing, then you get vibration and noise. I've heard of people rebuilding compressors by replacing spring... but have no hands on experience.

Posted: Sat Nov 03, 2007 1:20 pm
by maria_
Ralf Hutter wrote:Moved to Off Topic.

Also, we've at a couple threads about fridges over the years. A quick search should turn them up, right here in the OT Forum..

Oh, and WELCOME TO SPCR!!!
Tks, will check shortly.

Posted: Sat Nov 03, 2007 1:23 pm
by maria_
Bluefront wrote:Trying to determine how quiet these sorts of products are in a retail store is always difficult. The salesmen are no help, and the ambient noise levels are usually too high.

I'd suggest visiting all of your friends and relatives....and anybody else you can. Then listen to the units they have. Leave the door(s) open for a short time to get the compressors turned on. That might work best.
That is exactly the point. Not possible to test them in retail stores. My brother suggests german makes as all of them have db ratings as standard. He suggested bosch but I think the only german i can find would be siemens which incidentaly does not have any db ratings on their site.

Posted: Sat Nov 03, 2007 1:25 pm
by maria_
Das_Saunamies wrote:I've yet to find a quiet fridge, they all make some noise when the compressor engages. There might be some that are quieter than others, but they'll likely be sold with the word "silent" plastered all over them. Easy to spot. :D

Best bet is insulation and good care. Some DIY with plywood and foam panels might be just the thing - then just keep it clean to improve cooling efficiency.
No such thing as "silent" tags here. All salesman say their fridges are quiet -- even for 45 db daewoos!

Posted: Sat Nov 03, 2007 1:26 pm
by maria_
alleycat wrote:I don't know if you have these where you are, but in remote locations with no electricity we use gas refrigerators which run on LPG. Also depends on whether you can get LPG bottles...

They are silent and efficient, however.
Unfortunately, absorption fridges are no option here.

Posted: Sat Nov 03, 2007 1:31 pm
by maria_
VanWaGuy wrote:DON'T block all the airflow to the fridge in an attempt to make it quiet!
Sorry, this is not an option. I do not want this noise in my house and it will remain blocked until compressor burns out. We do not have return policies here and they did not accept my fridge back. So after burning 2-3 of them which are all under 1 year warranty, I am sure they will refund my money and get rid of me. 4 days and it is still not burnt out. There absolutely is no airflow to the fridge (except maybe 3-4 cm where the plug is attached), but there is a/c cooling in the house at the moment with ambient at 23C (winter no a/c).

Posted: Sat Nov 03, 2007 1:35 pm
by maria_
MikeC wrote:You could try to find out exactly where the noise is coming from. Here's a pretty good summary of things to look for.

It could be a fan, the compressor, or something touching the back of the fridge that's being vibrated.

If it's the compressor, there's probably not much you can do. AFAIK, in contains a sealed motor, and the motor is suspended inside with springs. If the springs are weak (which is what happens over time due to effects of gravity), and the motor touches the casing, then you get vibration and noise. I've heard of people rebuilding compressors by replacing spring... but have no hands on experience.
Thanks for the information. I am going through it. Fridge is new, the sound emanates from the compressor.

Posted: Sat Nov 03, 2007 4:15 pm
by maria_
Are there any specific brands/models you can suggest for fridges?

Posted: Sat Nov 03, 2007 11:41 pm
by Das_Saunamies
maria_ wrote:Are there any specific brands/models you can suggest for fridges?
Nothing that wouldn't smack of national and regional pride, but here goes: Helkama, Rosenlew and Cylinda have been good to our family - and I trust German makers by default. Of these, Rosenlew and Cylinda list dB ratings, apparently according to the standard(IEC 704-3).

Too bad about there being no silent models over there, Rosenlew and Cylinda make an effort of marketing theirs as quiet. Quietest was 38dB I think(most Rosenlew and Cylinda models).

And don't burn out your fridges, whatever your reasoning, you'll just risk damage to your apartment. :?

Posted: Sun Nov 04, 2007 1:34 am
by maria_
I see many models with db ratings of 35-36 in dooyoo.de. Bosch and AEG.

I have no access to these fridges and I am not willing to pay as much as a car for a fridge.

Here are few questions:

1. This fridge apparantely has a fan that blows to the freezer department (I assume for defrosting). This makes a bit of noise too. Is there a way to disbable that (I know not!)?

2. If a same brand has 3 different size of fridges in the same model line... let's say 200 lt, 250 lt, 300 lt... Would all of these fridges be using the same compressor? Or would the smaller model might be using a different compressor with less noise/less power?

3. Would the sound increase as the capacity of the fridge increases? I mean, would the noise of the compresor increase if its power increases?

4. The freezer compartment has a setting of 1-to-9 and the refrigerator compartment has min-normal-max. My freezer is almost always unused. Which setting would work best to keep the fridge quiet or to stop the compressor from engaging? Freezer:1 Ref:Normal?

5. I couldn't find a definitive answer even though I read all fridge topics here: Is the urban myth that filling up the fridge with water bottles instead of keeping it empty help with the noise? Would it make the compressor engage less often? I don't open the door of the fridge too many times a day, refrigerator is 75% empty most of the time, freezer 100% empty almost all the time. Assuming the door is being opened once a day, which one would be more advantageous soundwise: Keeping the fridge empty (air) or filling it up completely with mass (water)?

Posted: Sun Nov 04, 2007 2:08 am
by Das_Saunamies
I see many models with db ratings of 35-36 in dooyoo.de. Bosch and AEG.

Nice. Too bad they're not available. :(

1. This fridge apparantely has a fan that blows to the freezer department (I assume for defrosting). This makes a bit of noise too. Is there a way to disbable that (I know not!)?

Unplug and cover the wires. Probably lose some functionality, but doubt the fridge would cease to operate. Prepare to defrost manually every three months.

2. If a same brand has 3 different size of fridges in the same model line... let's say 200 lt, 250 lt, 300 lt... Would all of these fridges be using the same compressor? Or would the smaller model might be using a different compressor with less noise/less power?

Unknown. Smaller capacities take less time to cool, but same applies to warming up. Big with solid elements will need less cooling runs than small if the basic construction is the same. See question #5.

3. Would the sound increase as the capacity of the fridge increases? I mean, would the noise of the compresor increase if its power increases?

Unit-dependent. I have experience with aggregates mostly, but you can never tell of the noise by size. Factors like insulation and installation count. The sound will be different for every compressor, usually the big ones have more of a rumble and the small ones have a chirp - just like with all machines.
Usually small, efficient unit in solid casing is the best bet.

4. The freezer compartment has a setting of 1-to-9 and the refrigerator compartment has min-normal-max. My freezer is almost always unused. Which setting would work best to keep the fridge quiet or to stop the compressor from engaging? Freezer:1 Ref:Normal?

Probably. It'll at least cut out freezer cooling sooner. Hard to say what the overall effect will be, use trial and error(and read the manual).

5. -- which one would be more advantageous soundwise: Keeping the fridge empty (air) or filling it up completely with mass (water)?

It would balance temperature changes, yes. The water will keep its temperature better than air that just gets out when you open the door. Never tried that myself though, never had to. Doubt the weight of the bottles would be enough to make a difference.
If you're going to use plastic bottles they might result in increased condensation.
--

I'd still advocate DIY to direct the noise away from sensitive areas, maybe add absorption materials to reduce echo. Just had a browse through some sites, not terribly expensive, especially if you can score some old studio materials. Happy hunting.

Posted: Sun Nov 04, 2007 8:52 am
by flyingsherpa
maria_ wrote: 4. The freezer compartment has a setting of 1-to-9 and the refrigerator compartment has min-normal-max. My freezer is almost always unused. Which setting would work best to keep the fridge quiet or to stop the compressor from engaging? Freezer:1 Ref:Normal?

5. I couldn't find a definitive answer even though I read all fridge topics here: Is the urban myth that filling up the fridge with water bottles instead of keeping it empty help with the noise? Would it make the compressor engage less often? I don't open the door of the fridge too many times a day, refrigerator is 75% empty most of the time, freezer 100% empty almost all the time. Assuming the door is being opened once a day, which one would be more advantageous soundwise: Keeping the fridge empty (air) or filling it up completely with mass (water)?
Water has a MUCH higher heat capacity than air. So putting a bunch of water bottles in the fridge and freezer (leave the tops open in the freezer so the bottles don't break when it turns to ice) will help keep them cold with less energy (and less frequent compressor cycles). I don't know if anyone has measured this so I don't know how big a difference it would make... but I would bet that it is significant (maybe we could submit this idea to Mythbusters so they could test it). I do this in both my fridge and freezer compartments for energy savings. Can come in handy when there is a water pipe leaking and they shut off your water for a day or two... happened to me last year.

Posted: Sun Nov 04, 2007 9:16 am
by lm
Buy a chest freezer, install a modified thermostat, and witness 2minutes/hour duty cycles :)

Posted: Sun Nov 04, 2007 10:27 am
by Erssa
Maria_: Couple of months ago I was in the same situation as you are now. I had recently moved to a studio apartment and the fridge in the apartment was old an terribly loud. The compressor went off every 9 minutes and was on for almost 10minutes at a time. It was driving me crazy so I called my landlord and requested a new fridge.

I went and bought this Rosenlew which is supposedly 40dBa and I can say that it's pretty quiet. It has a 138lts fridge(?) and a 42lts 4 star freezer compartment which can freeze 3 kilos/24h.

I'm pretty happy, not because it's totally silent, but because it feels like the compressor never goes on. It's definately not inaudible. If I pay attention I can hear when it goes on, even if I watch TV. But the noise is not really that intruding. Noise signature is importants just like with computers. The old fridge had a high pitched whine, this new one has sort of a low murmur sound which is tolerable.

Rosenlew is a finnish brand of Electorlux, so I suppose Electorlux freezers behave pretty much the same way. I don't know what brands are available in middle east, but AEG-Electrolux and Zanussi are also owned by Electrolux. I have also seen Whirlpool fridges with 38 dBA rating.

I think the most important thing to look for in a new fridge is the power consumption. Buy one with at least A-grade efficiency or preferably A+. I'd like to think that the more efficient models also have their compressors on the least amount of time. Same goes for the size of the fridge. Don't buy any bigger then you really need. Smaller fridge equals lower power consumption. It's an environmental act that will help you save in your electricity bill.

And like most people here have already said, whatever you do, don't block the air flow to the radiator. The compressors runs longer and more often in a hot temperature. Blocking up the air flow increases the duty cycles of the fridge.

Posted: Sun Nov 04, 2007 11:52 am
by Das_Saunamies
A thought occurs: ducting. You could experiment with ducting if you have easy access to a cool intake and somewhere to exhaust warmer air, see if you can get circulation going. Will help cool the fridge down faster, spelling for less activity from the cooling.

Posted: Sun Nov 04, 2007 12:15 pm
by tibetan mod king
lm wrote:Buy a chest freezer, install a modified thermostat, and witness 2minutes/hour duty cycles :)
Is this for real? Where would one find an appropriate thermostat? Or find instructions on how to build one? Thanks.

Posted: Sun Nov 04, 2007 1:43 pm
by maria_
Das_Saunamies wrote: Unplug and cover the wires. Probably lose some functionality, but doubt the fridge would cease to operate. Prepare to defrost manually every three months.
Das_Saunamies, thanks for all your input, points well understood.

I don't mind defrosting manually once every 3 months or once a month. What exactly do i need to unplug or cover?

Posted: Sun Nov 04, 2007 1:50 pm
by maria_
flyingsherpa wrote:
maria_ wrote: 4. The freezer compartment has a setting of 1-to-9 and the refrigerator compartment has min-normal-max. My freezer is almost always unused. Which setting would work best to keep the fridge quiet or to stop the compressor from engaging? Freezer:1 Ref:Normal?

5. I couldn't find a definitive answer even though I read all fridge topics here: Is the urban myth that filling up the fridge with water bottles instead of keeping it empty help with the noise? Would it make the compressor engage less often? I don't open the door of the fridge too many times a day, refrigerator is 75% empty most of the time, freezer 100% empty almost all the time. Assuming the door is being opened once a day, which one would be more advantageous soundwise: Keeping the fridge empty (air) or filling it up completely with mass (water)?
Water has a MUCH higher heat capacity than air. So putting a bunch of water bottles in the fridge and freezer (leave the tops open in the freezer so the bottles don't break when it turns to ice) will help keep them cold with less energy (and less frequent compressor cycles). I don't know if anyone has measured this so I don't know how big a difference it would make... but I would bet that it is significant (maybe we could submit this idea to Mythbusters so they could test it). I do this in both my fridge and freezer compartments for energy savings. Can come in handy when there is a water pipe leaking and they shut off your water for a day or two... happened to me last year.
Where can we get some scientific/factual data on this? Of all the things on earth, someone surely must have tried it.

Posted: Sun Nov 04, 2007 2:05 pm
by maria_
Erssa wrote: I'm pretty happy, not because it's totally silent, but because it feels like the compressor never goes on.
My 180 lts LG fridge was like this too for the first few years. I barely noticed it, also i think its compressor engaged only once or twice a day. Therefore I did not find it necessary to do any measurements. It was not an issue at all. [I do have watercooled fanless setups last 7-8 years on my computers, so no, the fridge's sound didnt get to fore once other noise is eliminated.]
I think the most important thing to look for in a new fridge is the power consumption. Buy one with at least A-grade efficiency or preferably A+. I'd like to think that the more efficient models also have their compressors on the least amount of time. Same goes for the size of the fridge. Don't buy any bigger then you really need. Smaller fridge equals lower power consumption. It's an environmental act that will help you save in your electricity bill.
I don't really care about the electricity bill, noise is my concern. I dont mind paying double on electricity if fridge will be quiet. And as for the environmental part, it is not top of my priorities, greenpeace and dolphin lovers can spend their lives on it... I drive a 7.0 lts V8 vette and i like to pollute :)

And like most people here have already said, whatever you do, don't block the air flow to the radiator. The compressors runs longer and more often in a hot temperature. Blocking up the air flow increases the duty cycles of the fridge.
I don't mind if the compressor is on 24/7. I don't hear it any more. So the fridge will be insulated until the compressor burns out or explodes. I hope it gives a warning beforehand so that i don't lose my chateau d'yquems :)

Posted: Sun Nov 04, 2007 2:11 pm
by maria_
I think the best bet would be to set up a timer so that the fridge is off between 0100 hours to 0700 hours.

You guys are very helpful. I would like sincerely thank you all for the time you spent reading/writing on my issue.

UPDATE: Fridge is making some water-dripping or leaking sounds inside its pipes near the freezer compartment [nothing leaking]. Is this normal behaviour on a new fridge or is it time to take my wine bottles out? :)

Posted: Sun Nov 04, 2007 3:11 pm
by alleycat
tibetan mod king wrote:
lm wrote:Buy a chest freezer, install a modified thermostat, and witness 2minutes/hour duty cycles :)
Is this for real? Where would one find an appropriate thermostat? Or find instructions on how to build one? Thanks.
Here's one.

Posted: Sun Nov 04, 2007 10:49 pm
by Das_Saunamies
maria_ wrote:
Das_Saunamies wrote: Unplug and cover the wires. Probably lose some functionality, but doubt the fridge would cease to operate. Prepare to defrost manually every three months.
Das_Saunamies, thanks for all your input, points well understood.

I don't mind defrosting manually once every 3 months or once a month. What exactly do i need to unplug or cover?
You're welcome.

And the fan needs power, right? Just disconnect the wires going to it and add insulation to the bare heads(electrician's tape). That's what I would do if I wanted it dead, but I don't think it's an audible component. Not as audible as the compressor anyway.

Up to you. I'd rather not mess with integral parts. Check the manual again, see if setting the freezer to minimal operation is sufficient.

Posted: Mon Nov 05, 2007 3:12 am
by Erssa
maria_ wrote:UPDATE: Fridge is making some water-dripping or leaking sounds inside its pipes near the freezer compartment [nothing leaking]. Is this normal behaviour on a new fridge or is it time to take my wine bottles out? :)
I think it is normal. It's probably just condensation water coming out of the fridge. The water usually ends up in a container near the radiator where the radiators heat will cause it to dissipate into air.
maria_ wrote:
Erssa wrote:I think the most important thing to look for in a new fridge is the power consumption...
I don't really care about the electricity bill, noise is my concern. I dont mind paying double on electricity if fridge will be quiet. And as for the environmental part, it is not top of my priorities, greenpeace and dolphin lovers can spend their lives on it... I drive a 7.0 lts V8 vette and i like to pollute :)
Don't get me wrong. I'm far from environmentalist. But wasting money is just... a waste. Plus, I believe power consumtion correlates with compressor power cycles.

You seem happy with your solutions and it probably is the only solution you'd be happy with. I think you are so possessed by the noise, that it doesn't matter which manufacturer makes the fridge, they'd all be too loud for you ;).

Posted: Mon Nov 05, 2007 4:33 pm
by maria_
Erssa wrote: I think it is normal. It's probably just condensation water coming out of the fridge. The water usually ends up in a container near the radiator where the radiators heat will cause it to dissipate into air.
Thank you, that is right.
You seem happy with your solutions and it probably is the only solution you'd be happy with. I think you are so possessed by the noise, that it doesn't matter which manufacturer makes the fridge, they'd all be too loud for you ;).
This indeed is not true. I was very happy with my old 180 lts LG fridge (lasted 7 years i guess before I gave it away in good condition to a friend). The problem with that was recent... last 6 mts or a year or so... compressor got louder and cycles became more frequent. It was not an issue before. I looked for hte same model but couldn't find it. Obsolete probably.

Believe me, I rarely create problems out of thin air -- everything i do is out of pure necessity.

That is how it looks now. I do not have any fresh air entering from any sides except a 3 cms hole at the top. The fridge is sitting also on insulation foam. There is a 6 cms gap between the radiator and the wall. Absolutely silent, no compressor or fan sound except that water-dripping. It is not the water that hits the plastic near compressor. That sound is coming within the fridge inside its pipes. And there does not seem to be anything i can do about it.

Let's see when the compressor will burn out.



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