Advice on DIY refrigerated cabinet please?

[431neb]

So I have this ridiculous bar that needs a support crew of 40 odd freezers to make it run nicely. What I would like to do is insulate the cabinet below and attack one of my existing fridge/freezers for parts and utilise them to refrigerate the cabinet, thus doing away with two freezers that flank my bar (one to flood and cool the font and one for the kegs - yep 40 was an exaggeration). I just got a 700 dollar electricity bill so I'm pretty motivated.


Has anyone had a crack at a project like that? The insulation is no trouble but the fridgy stuff is a bit more complicated. I'm able to make a copper condenser if needed but I think I may need an aftermarket evaporator with a radiator and fan style arrangement… Anyway you can see I'm struggling a bit. The internet is awash with all sorts of air compressor ideas for fridge compressors but not much along the lines I want. There are marine kits available but I'm pretty good with my hands and I have millions of tools and access to an Air Con gas compressor/ vacuum pump thingy….

I saw one fella who made his own refrigerated travel esky on one of the caravan forums and I imagine what I need is quite similar but a little more advice would be great.

I'll post some pics of the space under the bar later. It's quite large and would easiliy accommodate 7 kegs and a 20 or 30 litre glycol reservoir for the font.

 

[431neb]

As promised the underside of the bar and the "herd"of freezers that are shitting me to tears.

Apologies for the shitty pics. Don't bother opening them - they aint much bigger when you do.

 

[431neb]

The responses here have been so overwhelming I thought I would call a fridgy today and find out if I really am on crack. The conclusion was that doing this would cost more money than buying a marine kit and fitting that .

BUT

I'm a tightarse so I kept looking and discovered one useful thread after googling "Fridge disection". Actually "mini fridge TOTAL disection" would probably work better. Anyway this guy has done it. It's a bit rough but it can be done. I am wondering if it might be possible to cut the front off a bar freezer and mastic the remaining section into the side of my enclosure leaving the radiator bit (the back) out in a well ventilated part of the adjacent cupboard. With a trusty STC keeping the temps right of course.

My old kelvinator might go under the knife too but I need to find out if my neighbours air con gas vacuum pump thingy can empty the fridge gas and then put back in after reconfiguring the hardware.

Food for thought.

 

[SmallFry]

You truly are a special man. I wish you the best of luck.

Maybe make sure the life insurance is fully paid up before you commence. Just sayin'

 

[Jaded and Bitter]

I guess if you want lower running cost then you need less fridges running and less heat soak. ie greater efficiency.

In order to achieve this you need to say only have one fridge running and have better insulation.

Having seen antique wooden bar fridges being used in trendy pubs I know wood can work. I'd say insulate the hell out of your bar (think bottlo walk in style) with the thickest styrofoam you can get and make sure theres no cracks, joints etc. Do the floor with a bit of marine ply over styro, inside doors, underneath fonts etc.

I know theres a newish building product (may not be used in your area), which is like a single brick thickness of styro with a layer of fiberglass on the outside (for render). Id look at that.

Your idea then to graft in the freezer could work nicely, but you could also cut it down and run a l pumped glycol system with radiator and fan setup in the bar. Think of the system in a bottlo fridge. Small radiators and fans are available on ebay from China. Just insulate the crap round the heat exchanger unit. Prolly also get around frigging with the gas system.

 

[Feldon]

There's this...

http://www.storeitcold.com/index.html

 

[431neb]

You truly are a special man. I wish you the best of luck.

Maybe make sure the life insurance is fully paid up before you commence. Just sayin'

Bah. All part of the fun fella. Come over and give me a hand!

Feldon, that looks interesting but at 300 odd bucks for the coolbot and 400 for a through the wall aircon unit - as neat as that would be- It's pushing up to the price of an off the shelf marine refrigeration kit. Appreciate your effort though. I wonder if a PID could be hacked into the controls for an AC unit thus getting the same control for 250 less.

 

[431neb]

I guess if you want lower running cost then you need less fridges running and less heat soak. ie greater efficiency.

In order to achieve this you need to say only have one fridge running and have better insulation.

Having seen antique wooden bar fridges being used in trendy pubs I know wood can work. I'd say insulate the hell out of your bar (think bottlo walk in style) with the thickest styrofoam you can get and make sure theres no cracks, joints etc. Do the floor with a bit of marine ply over styro, inside doors, underneath fonts etc.

I know theres a newish building product (may not be used in your area), which is like a single brick thickness of styro with a layer of fiberglass on the outside (for render). Id look at that.

Your idea then to graft in the freezer could work nicely, but you could also cut it down and run a l pumped glycol system with radiator and fan setup in the bar. Think of the system in a bottlo fridge. Small radiators and fans are available on ebay from China. Just insulate the crap round the heat exchanger unit. Prolly also get around frigging with the gas system.

Insulation isn't a concern. I'm gonna start with 100 mm of polystyrene as a base. I know the product you are talking about and have considered it already. If I can get some cheap fridge panel, I'll use that. My biggest problem is the learning curve on the compressor and coolant stuff.

Glycol has been mentioned to me before but I'm just not up with how it could refrigerate the enclosure. One of the freezers that I run currently is for a ghetto "glycol" unit to flood the font. It's an aquarium pump and a plastic bin full of salt water. That's the freezer that will get the chop (maybe). It's old and the parts are simple.

The example I listed above on HBT relies on not disconnecting any of the refrigerant parts but I'll need to de-gas and re gas after everything has been moved about. That's where my knowledge falls down.

There's this fella with the bad spelling

http://dr-bangs.livejournal.com/7784.html

This fridge looks the same as mine.

http://www.youtube.com/watch?v=k08kYVoXZrQ

No-one talks about the gas escaping when the lines are cut. Is there a one way setup in the compressors or something ? I think I'm missing some fundamental aspect of the refrigerant.

 

[Eagleburger]

I was going to buy a fridge pump, but will first try a chest freezer with a tub of glycol solution inside. Have the glycol circulating into a eps insulated chamber. mainly because I got the chesty, it can only fit three kegs so will sooon be victim of upgraditis.

 

[431neb]

I was going to buy a fridge pump, but will first try a chest freezer with a tub of glycol solution inside. Have the glycol circulating into a eps insulated chamber. mainly because I got the chesty, it can only fit three kegs so will sooon be victim of upgraditis.

Something to remember is that a beer chiller from someone like Keg King is only about 800 bucks ( from memory) . I've spent a lot if time looking for a large enough chiller before I went down this path. I need a unit large enough for 5 taps plus the flooding if the font.

The chesty with the glycol ain't a bad idea but the bar I've got is on wheels so I want it to be relatively portable. Even though it already weighs 500 odd kilos!! Well... Realistically probably 300kgs.

 

[431neb]

I just bought a bar fridge for 20 bucks on gumtree. So given the very small financial risk, I'm simply gonna take the door off this little fridge and then seal it into the side of the larger compartment. I'll dial it down to the lowest temperature and then connect it to an STC1000. If I wire in a small fan to distribute the cool air within the enclosure I should get an even distribution and no temperature differentials.

Why do I think this will work? Firstly , the new enclosure will be much better insulated than the fridge, so only the back of the fridge will have to retain the cool air. This will be one unavoidable loss that is greater than the rest of the enclosure.

Secondly there will be a lot of thermal mass inside the new enclosure that will (hopefully, I think) buffer big temp swings. Ie 5 kegs at various levels and as much glycol as I can fit in there comfortably - at least 20 or 30 litres. Maybe more.

Third, It'll get opened once a week at best. Think about how much cool air drops out of a traditional fridge when the door is opened. The "door" for this will be a removable panel sorta like a fishing boat freezer only with the hatch on the side that'll be as well insulated as the other walls.

However, turning on the pump that floods the font will really pump heat into this system though. I know that on a hot day here in Melbourne, my old kelvinator upright freezer cycles non-stop when the flooding pump is on. It recirculates about 50 litres of very salty water and keeps the font at about 6 degrees. I may have to cap the cooling of the font at a certain temp to limit the work the fridge has to do during these times and look for a cheap (small) glycol unit.

Stoked with the bar fridge though! Only 20 bucks!

 

[431neb]

Nice chatting.

 

[conjob]

I'm interested in a similar thing in the future but for different reasons.

These are the only resources i've found:

http://www.homebrewtalk.com/diy-kegerator.html

http://www.homebrewtalk.com/f51/my-finally-finished-keezer-267412/

http://www.homebrewtalk.com/f51/resurrection-well-aged-whiskey-barrel-kegerator-134868/


I am a long way from even thinking about starting a build but would be interested to see how you go.

Good luck with it.

 

[431neb]

I'm interested in a similar thing in the future but for different reasons.

These are the only resources i've found:

http://www.homebrewtalk.com/diy-kegerator.html

http://www.homebrewtalk.com/f51/my-finally-finished-keezer-267412/

http://www.homebrewtalk.com/f51/resurrection-well-aged-whiskey-barrel-kegerator-134868/


I am a long way from even thinking about starting a build but would be interested to see how you go.

Good luck with it.

Cool threads conjob. I hadn't spotted them before despite searching for as many different names and jargon that I could think of. Some of the HBT threads and menus are a bit of a mystery to me actually..There's just so much of it...

I started lining the underside of the bar with polystyrene today. I got the sides, top and back done before I lost interest and went to the pub. I took some photos but they are pretty bad (as usual) but hopefully a little larger this time.

 

[431neb]

I just found this.

http://www.homebrewtalk.com/f11/new-fermentation-chamber-build-102846/

Almost exactly the same as what I'm doing. I can't wait to pick up the fridge.


Something I read in the thread linked above is that some fridges have coils in the walls that are intended to radiate a little extra heat outta the system rather than relying on the evaporator on the back to do all the work. My enclosure will dictate that almost half of the fridge will stick into my enclosure. Depending on the type of fridge I've bought I could be in trouble. It's a Daewoo I think. Maybe I should look that up …Bah, no time...

Family do today so no tinkering for now.

 

[Jaded and Bitter]

Top stuff, keep us posted.

found some sheets of half inch polystyrene for another brewery project meself today, yeah polystyrene rocks!

 

[OneEye]

The last link you posted isn't quite the same as yours. He's using that as a fermenting chamber, right? The fridge won't need to work nearly as hard as yours will have to to maintain actual fridge temps. Here's a link to a build that's more in line with what you're doing

http://www.homebrewtalk.com/showthread.php?t=484607

He gave up in the end as the load on the fridge was just too much and it was on far too long.

 

[431neb]

The last link you posted isn't quite the same as yours. He's using that as a fermenting chamber, right? The fridge won't need to work nearly as hard as yours will have to to maintain actual fridge temps. Here's a link to a build that's more in line with what you're doing

http://www.homebrewtalk.com/showthread.php?t=484607

He gave up in the end as the load on the fridge was just too much and it was on far too long.

OneEye, thanks for that link, I hadn't seen that one. Yeah I realise the other link is a fermentation chamber. There's many examples among the American sites. Essentially the same methods are employed in my build only the fridge will presumably work harder. That's why I've started with 100 mm of polystyrene insulation enclosing the refrigerated space to hopefully reduce the cycling of the fridge.

In the example you have linked (thanks again for that), I think that despite an awesome effort in most regards, enclosing the sides of the fridge and the evaporator, effectively gimped the ability of the fridge to do it's job. If I'm right then he's snatched defeat from the jaws of victory….So close. I plan to assist the air circulation around the condenser (The the hot bit), in order to increase the dissipation of heat.


Unfortunately the cheap bar fridge that I got on Gumtree is "no longer available" GRRRRRR. So I have a half finished project and no fridge. I figure a bar freezer is a better option but cheap bar fridges are more common so I'll keep looking and should be able to report on my success or failure soon.

The biggest fault in my system (as I originally planned it) , is cooling the font. I dunno if I mentioned it above but I was going to put a reservoir (water , glycol, whatever) in the chamber to recirculate through the font when needed. This really would be an unacceptable load on the fridge I think so I may have to devise a craftier way to cool the font. I have an idea but I'm still cyber-stalking the equipment. Another project… Why is it that starting projects is so much fun and finishing them is such a drag?

 

[431neb]

Time for an update.

I've completely installed the insulation on this bad-boy and put the fridge in place. As described above I took the door off the fridge so it sit's open to the new insulated chamber. I've got a lot less room than I had hoped for but it'll still fit the 5 cornies so that's OK.

My testing thus far has been pretty rudimentary as I was pretty time poor over the weekend. Unfortunately the temperature the fridge is holding sucks balls and I'm starting to think that this idea is misguided and foolish. Oooh that oughta bring on a bunch of I told you so's - if you haven't rained on my parade yet then it's called 20:20 hindsight and everyone has it.

So now that my ego is battered, I'll set about rationalising why the temperature sucks and see if I can't fix it.

A few points if I may….

1. The insulation is not sealed yet so there will be air leaks. Not significant ones but they will be there.
2. The cheap fridge I got is (unfortunately) one of the ones that dumps heat on its sides which sucks.
3. I lined one whole side with 70 mm foam thus gimping the heat loss.
4. There was no fan inside the compartment to move air.
5. The thermostat on the fridge was set to "cool" not "cold". I know that at "cool" the unmodified fridge sat at about 1 degree and at "cold" it got down to minus 7.
6. The back of the fridge is in a cramped cupboard (not ideal) and the computer fan I've installed still needs a tranny so it aint running yet.


This is a quote from the build thread linked above after he ran across similar problems...

"So I sealed the living s*it out of this thing and managed to get it to hold around 45 degrees."

45 fahrenheit is about 7.2 degrees celcius. Eerily similar to my 6 degrees but as I've suggested before there are probably things he could've done to help it along. To that end I have quickly installed a computer fan in the chamber and cranked the thermostat down to "cold". I think the fan will help but I suspect that the fridge was running continuously to hit 6 degrees to the thermostat adjustment probably won't help. I've also removed the insulation that ran across the side of the fridge.

My next move will be the fan behind the fridge and sealing the gaps.

Will putting the 5 kegs in the chamber (prechilled) help the performance of this fridge or hinder it? Does that additional thermal mass help to buffer the cycling of the fridge or is it just more "work". I'm unsure about the answer to that one.

Here are some pics. Sorry I've uploaded them too small again.

Part way through installing the bar fridge.



A view showing the foam on the side of the fridge . This has since been removed to allow an air gap.



The makeshift "door". It's just a jam fit in the hole.



The starting point for the fridge. It took about 3 hours (guessing) to hit 6 degrees.



Quick edit to note that it's dropped to 5.8 degrees in the time it took to write this post. The door was off for a while so whilst not a warm start it wasn't that cold either. Not compelling evidence though. Still think I might've wasted my effort on this one.

 

[Dips Me Lid]

Hey mate, the problem I see with that set up is that the fridge will struggle to reject any heat being boxed in like that, also that compressor will be undersized to maintain an area that seems about four/five times the size of what it was designed for, once you start adding in extra heat load like kegs, uninsulated joints/corners ect, it simply won't have the capacity to keep up with the work you asking the compressor to do and will more than likely overload/burn out the compressor.

To achieve cool room conditions in that space, you'd need to size up a small cool room style compressor and evaporator to suit, but then it starts getting pricey.

See how it goes, but I'd say that fridge will have a short lifespan.