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roosm
19-03-2015, 11:31 AM
Hi,

I have been struggling with building my own wine cooler at home. It is fairly large 128 bottles. About 5 feet tall, 3 feet wide and 1 feet deep.
From the beginning I attempted with Peltier TEC coolers, heatsinks, fans, 12V transformers etc.
This finally resulted in a solution which managed to keep the wine cooler a few degrees below ambient, but not nearly cool enough in the summer.

A neibourgh threw out a fridge a couple of months ago and I salvaged the cooling components from said fridge.

Yesterday I finally test-installed these in my wine cooler.
Good news, it is definitely powerful enough. I reached my target temp in half an hour and it didn't seem to slow down much after that. I am aiming for 13 degrees celcius or about 55 degrees farenheit.

In addition to the thermostat from the fridge itself (which I apperently broke when I cut the probe filled with gas) I have a second thermostat which can be set to turn on and off at specific temperatures reached within the wine cooler.

On the originial thermostat I found a lever which turns the fridge on when it is pressed. (Simulating pressure from the hot gas expanding within the probe/tube I guess).

So, the problem is that the compressor is too loud. There are no fans so the noise should come from the compressor and that is sure where it seems to come.

I have read that I should check that it is level (though it should be almost level at least), it stands on rubber feet, though is not bolted down.

Would it be possible to put a resistor in line with the fridge thermostat to make it run on less current, there by making it less effective but also less loud?

Any other suggestions?

Or would the only real option be to go out and by a new fridge-compressor?

I remember the compressor as being less loud when I tried it outside before installing it. That was at maybe a couple of degrees above freezing so might have to do with it?

Thank you!

Mike

Chris3000
19-03-2015, 12:06 PM
Could you show photos of your setup? I'd gladly see your cooler ;)

You could try placing a rectifing diode (or 2-3 in paralell to withstand current) in your mains supply to the compressor. This way the didode will cut half of the sine wave of AC going into the compressor, reducing power and speed of the electric motor in the compressor, by half.

Look for rectifing diodes like this - cost is probably like 0,5 Euro on the internet.
12290

BradC
19-03-2015, 12:37 PM
Er..um.. I've never seen an AC induction motor (which is what the compressor will be) run on DC which is what you will get if you do what Chris3000 suggests). I'm very willing to be proven wrong, but I suspect all you will see is either smoke, or a klixon cycling on thermal cutout.

The cooling system will be designed to run at an evaporator temperature far below that you are running it at. With such a high temp you will be working the compressor *hard*, and it will complain appropriately.

My parents wine fridge has a small evaporator it runs at about -10C and air is circulated over that by a fan. The compressor runs hot and moderately loud but not often. You could slow down the air-flow over the evaporator to get it *really* cold, that'll reduce the refrigerant mass flow and quieten things down.

The other thing you could do is put a fan on the condenser. By lowering the condensation temperature you won't make the compressor work as hard and it'll quieten down a degree as a result (probably not a lot, but every bit helps).

Most of that is theory mixed in with a bit of experience, however I'm *pretty* sure that putting a diode in there will end in tears.

Chris3000
19-03-2015, 01:10 PM
Er..um.. I've never seen an AC induction motor (which is what the compressor will be) run on DC which is what you will get if you do what Chris3000 suggests). I'm very willing to be proven wrong, but I suspect all you will see is either smoke, or a klixon cycling on thermal cutout.
Its not pure DC, you still get one half of the AC cycle which means (in Europe) you get 25Hz/230V insead of 50Hz/230V. If roosm is already thinking about buying new compressor, maybe he could just test the method that way? The theory says it should work by reducing speed by one half.

BTW: I tested a small hand grinder to see if this method works - it did, the gridner was running half the speed, and still works perfectly today. I prepared an extension cord with recifying diode in it to easily plug-in devices. Regular light bulbs are half as bright, and AC motors run half the speed.

hyperion
19-03-2015, 01:16 PM
Agree with Brad, a simple A/C compressor will not respond very well to creating DC as the input supply. If the compressor actually started, it might not have enough torque to actually turn over. The small start or potential relay will probably not function, thereby causing the compressor to not attempt to start.
Whilst commercial air conditioning units often have inverter driven compressors, the compressors are designed and built to operate with variable frequency A/C voltage as opposed to pure DC voltage.
The higher operational noise could be as a result of the higher operating pressures due to the 13degC target temperature.
Whilst it is all good fun experimenting, sometimes it is better to acquire the correct equipment for the task in hand.

roosm
19-03-2015, 02:35 PM
The higher operational noise could be as a result of the higher operating pressures due to the 13degC target temperature.
Whilst it is all good fun experimenting, sometimes it is better to acquire the correct equipment for the task in hand.

Okey, so lets say that it is deemed impossible to get a tolerable noise-level from my current setup.
What would the "correct equipment" for the task be?

Are there certain compressors, evaporators, condencers etc built for higher target temperature?

Could I somehow modify what I already have? (hard to answer I guess as you don't know what I have, and I have no clue of how to describe it).
It is however from a small fridge (half size), the evaporator is 20" x 20" approx... The condenser was the type that covers the back of the fridge, though I have bent it to be zigzagged into a more compact design as it is needed to fit the place where I keep the "hot side" of the wine cooler.

As the wine cooler is built into the space left by an old door being blocked in my 19th century appartment it is limited in depth to the thickness of that wall. That is 12" deep. The hot-side of the fridge is at the bottom of the fridge (just because the walls and roof of the fridge are built up of 19th century decorations) and is limited to 7 inch height.

The fridge is about 3 feet wide, so that isn't a problem.

I have yet to find anything built for this purpose that fits my need. As the other side of the back wall of the fridge goes into a space outside my appartment (in the stair case) I cannot put a through wall cooler there.

I will come back with some photos.

So if anyone knows of a product where the hot-side would fit inside a box 7 x 12 x 30 inch I would be very interested. (I might be able to accomodate a slightly higher compressor by some small modifications).

So from what I have learned so far I should get a fan or two to increase the airflow over the condenser, probably bolt down the compressor and maybe try to insulte the compressor a little so that it doesn't rattle the condenser, limit the evaporators air-flow, I guess I will try wrapping it in a towel or two and se how that goes as a start.

Anything else? Get a much smaller evaporator, or could I modify the one I have? Would I even be able to install a new one my self?

Thank you!

Mike

BradC
19-03-2015, 03:22 PM
BTW: I tested a small hand grinder to see if this method works - it did, the gridner was running half the speed, and still works perfectly today. I prepared an extension cord with recifying diode in it to easily plug-in devices. Regular light bulbs are half as bright, and AC motors run half the speed.

Just let me clear this one up properly. I may not know an awful lot about refrigeration, but I know enough about electricity to answer this one with absolute authority.

Your hand grinder uses what is known as a "universal" motor. That is a motor with field coils instead of permanent magnets, and a commutator, armature and brushes like a conventional DC motor. These motors will run on AC or DC, thus the name "Universal Motor". A refrigeration compressor is not a universal motor for these and more reasons :
A) Arcing brushes inside a hermetic shell would be bad
B) Brushes wear out relatively quickly and hermetic compressors don't.
C) Universal motor speed is controlled by a balance between power input and power output, a compressors speed is dictated by the motor configuration and number of poles, and the mains frequency.

An AC hermetic compressor is an induction motor and _requires_ AC (both polarities) to run. Even a DC compressor is really a 3 phase AC compressor just with a permanent magnet rotor rather than one that generates the field by induction.

Even if you spun the hermetic compressor by hand, it will _never_ run with DC (and yes, what you suggest is DC. Pulsating DC, but still DC). So please don't bother, it _will_ end in tears.

BradC
19-03-2015, 03:41 PM
Are there certain compressors, evaporators, condencers etc built for higher target temperature?

Look, the answer is absolutely yes. I'm the last person on earth that would suggest this because I'm a pig ignorant stubborn ham fisted do-it-yourselfer, but you _might_ be better getting to know a fridgy, buying him a couple of cartons and having him sort it out for you.

If _I_ were doing it here's how I'd tackle it (please anyone who spots a flaw in this correct me).
A ) You are looking at a target temperature not that much lower than your domestic environment, so your heat infiltration into the cabinet will be much lower than your average fridge, thus you need to move less heat per unit time and want a smaller compressor.
B ) You have a much higher thermal mass (being ~100 750ml bottles of grog - 75L of water and a lot of glass)
C ) Because you have such a packed interior, convection is going to be much smaller/slower

So, I'd go shopping the dump / second hand stores / anywhere that sells fridges / for the smallest compressor fridge I could find. Certainly less than 80W for the small ones (btw, post your compressor make and model number and we can show you how to look up the data to tell you how much heat it moves).

I'd make an evaporator out of 2 copper CPU heatsinks (with fans removed) bonded (soft soldered would be fine) to a couple of feet of 3/16" copper tubing and I'd look for the largest condenser I could find. I'd put the CPU heatsinks in a slot cut into some PVC drain pipe as a duct and I'd put a muffin fan in one end. Mount the whole thing vertically in the cabinet, pushing the cold air toward the top.

Based on a high evaporation temperature and low condensation temperature I'd use one of the capilliary tube calculators to calc out a tube to give me a rough evap temperature of just below 5 degrees C and set the thermostat in the cabinet to the desired temperature. You will get short sharp cycles while the bottle temp pulls down, and it should even out as things approach the desired set point.

You might need a few iterations of the cap tube length to get it right. I always start a foot long and just clip it back a bit at a time if I'm going for accuracy. Frankly as long as you don't freeze the evaporator you'll probably be ok.

To do this yourself you'd need :
A) A set of gauges
B) A Vacuum pump
C) A Recovery machine (or lots of dry ice)
D) Some refrigerant (you can be creative, lots of stuff has R134a in it)
E) Oxy of some kind. I've done it using plain Map/Pro (Propylene) but having gone Oxy it makes precise work on small stuff just so much nicer
F) Lots of patience, bloody minded persistence and a real willingness to learn the hard way

Now, this does not account for humidity control but that's another ballgame.

roosm
19-03-2015, 05:57 PM
A ) You are looking at a target temperature not that much lower than your domestic environment, so your heat infiltration into the cabinet will be much lower than your average fridge, thus you need to move less heat per unit time and want a smaller compressor.

Well during the summer we get ambient temperatures upwards of 27 degrees celcius inside our kitchen and in the staircase that temperature can go even higher. The wall between the staircase and wine cooler is brick, making it quite warm.



B ) You have a much higher thermal mass (being ~100 750ml bottles of grog - 75L of water and a lot of glass)
C ) Because you have such a packed interior, convection is going to be much smaller/slower

The wine cooler still has a lot of air in it. Not very packed. The shelfs stop 3 inch shy of each wall and about 8 inch shy of the ceiling in the cooler.
The shelves are this kind: http://www.quercia.se/Vinunic_skap_framifran.jpg



So, I'd go shopping the dump / second hand stores / anywhere that sells fridges / for the smallest compressor fridge I could find. Certainly less than 80W for the small ones (btw, post your compressor make and model number and we can show you how to look up the data to tell you how much heat it moves).

I'd make an evaporator out of 2 copper CPU heatsinks (with fans removed) bonded (soft soldered would be fine) to a couple of feet of 3/16" copper tubing and I'd look for the largest condenser I could find. I'd put the CPU heatsinks in a slot cut into some PVC drain pipe as a duct and I'd put a muffin fan in one end. Mount the whole thing vertically in the cabinet, pushing the cold air toward the top.


I am very greatful for your input, but you lost me after the bit above. The rest I didn't get at all.. =)

So no way to limit electricity to it to get it to slow down?

My evaporator uses a single tube which I do not understand? How does that work?

I will post my make and model of the compressor if I can find it on the unit.

If I cut any tubes I guess it is toast? I mean you would have to somehow refill it with refridgerant and seal it under pressure?

Mike

roosm
19-03-2015, 08:57 PM
The compressor says danfoss TLES4F and 102G.

Mike

BradC
20-03-2015, 02:40 AM
So no way to limit electricity to it to get it to slow down?

You could run it on a variable speed drive, but you'd not want to go slower than half speed or your lubrication would probably suffer pretty badly. I'd not go lower than 35Hz myself. It might work, it might seize the compressor, I've never done it on a hermetic compressor as yet and I'm not sure how they specifically pump oil. I know that Danfoss recommend their scrolls not go slower than 35Hz because the oil pump loses volume under there.


My evaporator uses a single tube which I do not understand? How does that work?

To simplify it, liquid refrigerant enters at one end and boils away absorbing heat as it traverses the tube, leaving as a vapor at the other end.


I will post my make and model of the compressor if I can find it on the unit.

You did that. Take the model and punch it into google. I came up with an efficient R134a compressor. Checking the capacity chart in the data sheet suggests the compressor is rated between -35C and -10C. At -35C the compressor should draw about 60W and at -10C it should draw about -118W. I'd hazard a guess that at your temps it's going to draw quite a bit more and complain quite loudly.


If I cut any tubes I guess it is toast? I mean you would have to somehow refill it with refridgerant and seal it under pressure?

Yes to both of those.

Short of completely replacing the cooling system you want to get the evaporator down to about -10C. You need to make the interface between the interior air and the evaporator less efficient. I don't see a *simple* way to do what you want to do. I'd honestly recommend talking to a fridgy about getting it done properly, after all it's what they do day in and day out whereas I just design security in tall buildings (about as far away from a fridgy as they come).

Magoo
20-03-2015, 03:32 AM
What is your target controlled condition for the wine collection, bearing in mind whites are totally different to reds and should be stored in different conditions, temperature and humidity for long term is critical.
At our place neither lasts very long , but 100 plus bottles would be a challenge for my family, fortunately or unfortunately my daughter works in the wine industry.
Also there are wines that are produced to be consumed and not keepers long term. But you obviously know your wines better than me. There are wine storage cabinets available on the net, may save a lot of hassle and grief. Dial up what ever conditions you need and walk away.

roosm
20-03-2015, 09:06 AM
What is your target controlled condition for the wine collection, bearing in mind whites are totally different to reds and should be stored in different conditions, temperature and humidity for long term is critical.
At our place neither lasts very long , but 100 plus bottles would be a challenge for my family, fortunately or unfortunately my daughter works in the wine industry.
Also there are wines that are produced to be consumed and not keepers long term. But you obviously know your wines better than me. There are wine storage cabinets available on the net, may save a lot of hassle and grief. Dial up what ever conditions you need and walk away.

Well.. This all started with the remodelling om my kitchen. I then got this old blocked door in the middle of my kitchen, where there were shelfs built somewhere around 1950-ies. After I tore all that down I was left with a "dead" space of about a wine-bottles height in depth, 3 feet wide and 6 feet tall (well it was a door-way). The Wall is about 20 inch deep minus the brick wall built inplace of where the outer door used to be.

So I asked what to do with this space where the sides and ceiling is these wooden mirror decorations from the year 1882, the back is brick and the depth is exactly made for a wine-bottle. I figured wine-cooler. So it didn't start with: I need the perfect place to store wine since I can't have a wine cellar in my appartment.
I rarely have any wines above 30 bucks and don't intend to store them for a lot of years. The size of the wine cooler wasn't decided by me but by the nature of the space. 128 bottles is far more than enough.

Since the No 1 criteria for the wine cooler is that we should keep the brick wall and 19 century wooden decorations anything that involved lining the sides with insulation or placing a preconstructed wine cooler there. This is first of all a piece of butiful furniture/design and second a wine cooler.

I don't think it would be feasable (without a lot of help / input) to do this DIY to the full extent that you lined out BradC.

I am quite handy, have a better than normal understanding of electricity etc but I am not an engineer. Well I am a computer engineer of sorts... But keep to code and software, not hardware.

So OK this compressor is obviously not the best for this job.

What I have learned:
A compressor will surely do the job. Whereas a peltier is just not enough. And I would require an outside unit to like the heat/cold-air-pumps use to get it to work.

So compressor is the way to go.
I have also learned that there are different compressors suited for different jobs.

Where would I find one that would be better for this job?
Target-temp in the where-abouts of 13 degrees Celcius would be optimal.
Maybe 5-10 or so for the evap it self?


By the way.
I tried wrapping the evap with a towel and managed to reach -5 degrees C inside the towel with this setup. The wine coller space only got down to about 15 degrees with that setup. Though it is currently very poorly insulated from the hot side where I was very hot. The condenser was burning hot to the touch.
So I added a fan, which made it slightly better.
But the noise is still waaay to loud at evap at -5 and condenser quite hot.
I guess the compressor is still working its ass of as it hasn't reached -20 or so yet.

So any more ideas?

Any widely used compressor for fridges or similar that I could find used and gut for parts?
Maybe for A/C units? They might not go as low as -35? =)

Thanks,
Mike

roosm
20-03-2015, 11:50 AM
You could run it on a variable speed drive, but you'd not want to go slower than half speed or your lubrication would probably suffer pretty badly. I'd not go lower than 35Hz myself. It might work, it might seize the compressor, I've never done it on a hermetic compressor as yet and I'm not sure how they specifically pump oil. I know that Danfoss recommend their scrolls not go slower than 35Hz because the oil pump loses volume under there.

How would I do that? If I get to the point where I am certain I can't use this compressor at full speed and still get tolerable noise, I might as well try to slow it down and see what happens?
Would you expect some kind of explosion or seize, stop? =)

Mike

roosm
20-03-2015, 01:48 PM
My very basic (though far better than two days ago) knowledge of compressors tells me I would want this:
http://www.secop.com/fileadmin/user_data/SEPS/datasheets/tl25g_102g4250_r134a_220v_50hz_60hz_09-2011_desd400t122.pdf
or even better:
http://www.secop.com/fileadmin/user_data/SEPS/datasheets/pl35g_101g0250_r134a_220v_50hz_60hz_09-2014_cnsd400e202.pdf

Would those help me alot when it comes to the noise?

Seems like the TL2.5G is more common in fridges at least?

I guess I have to visit a local used fridge store and crawl around on the floor looking at the compressors? =)

BradC
21-03-2015, 02:57 AM
How would I do that? If I get to the point where I am certain I can't use this compressor at full speed and still get tolerable noise, I might as well try to slow it down and see what happens?
Would you expect some kind of explosion or seize, stop? =)

Mike

Ok, after looking at the compressor data sheet again I'm not sure the speed reduction will work. Well, I know it will _work_, I just don't know the short to medium term implications for the compressor. I know from personal experience it works with permanent capacitor motors. This one can be wired as an inductive run or capacitive run and both configurations on the data sheet show a PTC device between start and run windings. I honestly don't know how that will behave if you reduce the frequency/voltage going to the compressor.

Either way, you'd not get an exposion. It'd either burn out the start winding or seize due to inadequate lubrication.

In theory if you were going to try it, you'd buy a single phase to three phase 240v inverter from e-bay or similar, and wire this compressor's active and neutral wires to two outputs on that device. You could then start it on 50Hz and reduce the frequency to slow the compressor down. The inverters are pretty cheap these days. The last lot I bought ran around $80 each. If you were in Australia I'd lend you one, I use them to reduce / increase the speed on my drill press and reduce the speed on my pool pump (both induction motors).

Something like this (I buy manufacturer direct from China because I usually bring in ~20 at a time).
http://www.ebay.com/itm/0-75kw-Frequency-Drive-Inverter-Converter-VFD-220V-240V-1HP-integrated-IGBT-/301551210884?pt=LH_DefaultDomain_0&hash=item4635da5184

roosm
22-03-2015, 06:29 PM
Ok, after looking at the compressor data sheet again I'm not sure the speed reduction will work. Well, I know it will _work_, I just don't know the short to medium term implications for the compressor. I know from personal experience it works with permanent capacitor motors. This one can be wired as an inductive run or capacitive run and both configurations on the data sheet show a PTC device between start and run windings. I honestly don't know how that will behave if you reduce the frequency/voltage going to the compressor.

Either way, you'd not get an exposion. It'd either burn out the start winding or seize due to inadequate lubrication.

In theory if you were going to try it, you'd buy a single phase to three phase 240v inverter from e-bay or similar, and wire this compressor's active and neutral wires to two outputs on that device. You could then start it on 50Hz and reduce the frequency to slow the compressor down. The inverters are pretty cheap these days. The last lot I bought ran around $80 each. If you were in Australia I'd lend you one, I use them to reduce / increase the speed on my drill press and reduce the speed on my pool pump (both induction motors).

Something like this (I buy manufacturer direct from China because I usually bring in ~20 at a time).
http://www.ebay.com/itm/0-75kw-Frequency-Drive-Inverter-Converter-VFD-220V-240V-1HP-integrated-IGBT-/301551210884?pt=LH_DefaultDomain_0&hash=item4635da5184


Well this seems like a long shot and if I get one of these and ruin my compressor I can't really see anything else useful I can do with it. Therefore it seems like I am better off spending my money on what should/will work better.

I can get a compressor that are purposed for a boat fridge for a decent price, well around 300 euro. Its tech spec looks better than the one I have, right?

Can I wire it for HBP? Then it seems good, right? What do you think?

http://www.novakool.com/support/bd35f_compressor_data.pdf

It comes with a small-ish condenser mounted around the compressor which I can cool with a fan or two.
It also comes with a O-shaped evap. 240 x 85 x 210 mm.

http://www.thermoprodukter.se/templates/product.asp?ProductGuid=2001K&GroupGuid=147

Again, thanks for all your help!

Mike

BradC
23-03-2015, 02:07 AM
do with it. Therefore it seems like I am better off spending my money on what should/will work better.

I can get a compressor that are purposed for a boat fridge for a decent price, well around 300 euro. Its tech spec looks better than the one I have, right?

Lucky you! Those are about $1500 in Australia. I can't even source the BD35F and control box for less than about $800 here. Yes, I have a BD35F based unit I built out of a wrecked car cooler that I use as a vapor trap for my vacuum still. I run that between 2C & -25C depending on what I'm distilling. The best part is you can set the compressor speed directly with a resistor so you can tailor it to whatever you want it to be. See at 10C it will move ~130W, so you won't run short of capacity. You will need a 12 or 24V DC power supply to drive it. No big deal.

You could get that evaporator and stretch it out to a flat plate across the back of the cooler. Plus even at full speed the BD35 is a quiet little compressor. I'd still put a fan blowing across the evaporator.

Best part about the isotherm units is they are pre-charged and easy to put together. Ideally in a perfect world you'd get a fridgy to evacuate and properly set the charge level, but in practice they work pretty well out of the box. We have one with a Eutectic plate on the boat.

I'm not saying it's the perfect solution, but it's going to work better than what you have now and you won't need to stuff around with custom parts. Also, the compressor runs much faster and therefore the noise it generates has more of a high frequency component which turns out to be easier to silence.

roosm
23-03-2015, 06:46 AM
Lucky you! Those are about $1500 in Australia. I can't even source the BD35F and control box for less than about $800 here. Yes, I have a BD35F based unit I built out of a wrecked car cooler that I use as a vapor trap for my vacuum still. I run that between 2C & -25C depending on what I'm distilling. The best part is you can set the compressor speed directly with a resistor so you can tailor it to whatever you want it to be. See at 10C it will move ~130W, so you won't run short of capacity. You will need a 12 or 24V DC power supply to drive it. No big deal.

You could get that evaporator and stretch it out to a flat plate across the back of the cooler. Plus even at full speed the BD35 is a quiet little compressor. I'd still put a fan blowing across the evaporator.

Best part about the isotherm units is they are pre-charged and easy to put together. Ideally in a perfect world you'd get a fridgy to evacuate and properly set the charge level, but in practice they work pretty well out of the box. We have one with a Eutectic plate on the boat.

I'm not saying it's the perfect solution, but it's going to work better than what you have now and you won't need to stuff around with custom parts. Also, the compressor runs much faster and therefore the noise it generates has more of a high frequency component which turns out to be easier to silence.

Everything seems really good with that unit. It is perfect size for my "hot side" I allready have 450W of really quiet 12V from the computer PSU that I used for my peltier! :)

I thought I could control speed with a resistor from the spec. Still not sure how.
The company that builds them is Swedish I think? At least they have a swedish office that I have been in contact with. They however thought there were better things on the market for me, I can't find any.
Plus, since it is a boat-DIY-solution it is not totally worthless on the open market.
Too bad one just went on Swedish Craigslist without evaporator for 80 euro!

I guess I'll order one of those and use the other compressor - kit to build a beer fermentation cooler. Just need some kind of way to set the temp...

Thanks,
Mike

roosm
23-03-2015, 09:57 AM
The best part is you can set the compressor speed directly with a resistor so you can tailor it to whatever you want it to be.
How do I do that? Maybe it will become obvious once I have one in front of me.



See at 10C it will move ~130W, so you won't run short of capacity. You will need a 12 or 24V DC power supply to drive it. No big deal.
As I said, the PSU should do the trick.



You could get that evaporator and stretch it out to a flat plate across the back of the cooler. Plus even at full speed the BD35 is a quiet little compressor. I'd still put a fan blowing across the evaporator.
I'll probably keep it in its O-shape as it would fit better and look nicer.
I don't see why I would want the fan? Wouldn't that get the evaporator warmer and thus a noisier comrpessor?



Best part about the isotherm units is they are pre-charged and easy to put together. Ideally in a perfect world you'd get a fridgy to evacuate and properly set the charge level, but in practice they work pretty well out of the box. We have one with a Eutectic plate on the boat.
Yeah, I like that part.



I'm not saying it's the perfect solution, but it's going to work better than what you have now and you won't need to stuff around with custom parts. Also, the compressor runs much faster and therefore the noise it generates has more of a high frequency component which turns out to be easier to silence.

It is not the perfect solution. Ok, but best guess, is it good enough?
I can live with the wines beeing no colder than 17 degrees in summer (when ambient is 27 for a month). So there should be enough power. The noise is my biggest concern.

What would be a solution that would be more quiet? And would that fall in the same price range? Or many times as much?

Thanks again,
Mike

*EDIT*
I promised a picture. Here goes:
12655

Not the best picture, but it would give you an idea of what I have going on. (It isn't rotated on my computer, can't tell why it is rotated here?)
The brick wall, the wooden decorations, the tinted glass door. Everything works well in the appartment.

The Viking
23-03-2015, 01:40 PM
Hej Micke,

Just a word of warning incase you weren't aware, as this solution would be purpose built on site you will have to ensure it complies with "Svensk Kylnorm" (F-Gas legislation for the rest of you). The main part there that might throw you is that anyone working on refrigeration circuits needs to be certified and registred.
And I do know that in Sweden that is a legislation that actually is enforced, with both hefty fines and jail times been handed out by the courts in the past. (unlike, for example, UK where it is seen more as a reccommendation)

:cool:

roosm
23-03-2015, 02:14 PM
Hej Micke,

Just a word of warning incase you weren't aware, as this solution would be purpose built on site you will have to ensure it complies with "Svensk Kylnorm" (F-Gas legislation for the rest of you). The main part there that might throw you is that anyone working on refrigeration circuits needs to be certified and registred.
And I do know that in Sweden that is a legislation that actually is enforced, with both hefty fines and jail times been handed out by the courts in the past. (unlike, for example, UK where it is seen more as a reccommendation)

:cool:

Hej,

As isotherm and thermoprodukter market this product as a DIY (build your own refridgerator in your boat) kind of deal couldn't this be exempt as you do not do any wiring, welding, filling of refridgerants or anything like that?

I found the government text regarding this and it seems like most of it is exempt if the two parameters 1) The system contains less than 3000 grams f-gas and 2) The installation is done privately ( or for education / research) and not by a professional are true.
So from what I can understand, I should be good to go.

Mike

The Viking
23-03-2015, 09:07 PM
OK,
The rules are slightly different on boats as they comes under the transport category but you are talking about a fixed installation. When it comes to the 3kg exemption that is for factory built hermetic units (no pipework to be done on site).
However, it is a few years since I worked in Sweden and were registered there so I might be wrong.

The best you can do is to contact Svenska Kyl och Värmepumps Föreningen, info@skvp.se. They should be able to give you the right advice.

:cool:

roosm
12-06-2015, 07:48 AM
Well, ok, since the unit was made for "user"-installation and everything was pre-connected I was good to go.

I finally got a BD35f isotherm unit.

This is considerably more quite than the chopped up fridge-compressor. Installation was extremely easy as the pre-connected pipes were all flexible (should just be a tiny bit careful when straightening the evaporator pipe as it was coiled up to be packaged in a smaller box.

Anyhow. The noise levels are now tolerable. (In fact they are good in the kitchen, but worse in our bedroom as the compressor-box-outlet is pointed right toward our bedroom door and when lying down you get a straight angle so you can actually see the compressor. Even putting a book like 6 inches from that outlet but blocking my line of sight made a world of difference.) Had to exchange the original fan that came with the unit though as it was loud as hell and you couldn't change speeds of it. Replaced it with a Noctua 120 mm CPU fan. Works much better.

The results? Well the winecooler now drops to about 4 degrees C (8 F) below ambient. I haven't run the unit for more than maybe 10 hours yet so might still be slowly dropping as it cools the brick wall at the back of the fridge as well as the bottles them self. This isn't really great, but I think I can make it better.
I 'll have to remodel the compartment for the compressor and condenser a bit to be able to make it fit while still being able to isolate it from the fridge.

My idea here is to but the compressor in the middle of my "box" at the bottom of the fridge. Put styrofoam on the ceiling of the box to get insulation between the hot and cold side. Make 2 holes, one to the left and one to the right of the front of the box (facing the room). Here I would place one fan that blows hot air out of the box and another that blows ambient air into the box. I would also keep the fan blowing on the compressor and condenser. Maybe connect a duct between the condenser-fan and the intake-fan so that cool air is steered in the right way.

Then I will have to sound-proof the box as much as possible (can't really do anything where the fans are, but still.
Any idea if there are better options than styrofoam and what should I use for sound-proofing?

So that should take care of the noise and effectiveness issues somewhat.

The next part is the evaporator.
It freezes over. Very quickly.
First I tried with no fan.
Then I tried with a fan blowing cool are out of the evaporator (it is shaped as bucket really, an elliptical cylinder with a "bottom" that is used as a bracket to screw it to the wall.
Then I tried with the fan blowing hot air into the "bucket" which works better, but still not good enough.
I might try putting one fan blowing into the evap and one blowing out...

I might also try to fasten a heatsink to the evaporator somehow? Like a CPU-heatsink bolted to the evap on the inside of the evap...?

Ideas?

Looking at the bd35f technical specs I find that using it without a resistor/without a thermostat by jumpering the two posts should run it at 2000 rpm and should allow evaporator temperatures of 10 degrees Celcius. Considering my target temp is 16 degrees C I would then be right on target with TD of (6 degrees C) 10 degrees F (which I read would be correct for not getting to much humidity out of the air and onto the evap dripping all over)?

Is that feasible? I mean, can I get the evaporator to actually exchange heat with the air inside the fridge so efficiently that I don't get more than 10 degree F temperature difference?

In that case the compressor should be able to provide 140-170 Watts of cooling. Which considering my quite large and quite poorly insulated fridge would give me Somewhere around 7 degrees celcius below ambient. And that would be fine for me. That would get me through most of our summer with temperatures at 17-19 degrees C in the fridge. Still very drinkable wine temperatures. =)

Oh, one more thing... 2000 rpm would be the quietest setting right?
2000 rpm quiet?
3500 rpm loud?

Thanks,
Mike