Mini fridge experts or anyone.....

[Kmcogar]

I just added a collar to my mini fridge. As pictured. I didn't pull the freezer portion of the fridge down because I can fit a corny keg underneath it no problem. I also have a fan running inside the fridge as well.
I caulked and used foil tape everywhere and then some. I thought I gotta a pretty good seal everywhere but....

24 hours later, I put a cup of water in the fridge with a thermometer. It only got down to about 52 degrees. So I touched the side of the fridge and it was very hot. I then check the compressor and it is running very hot as well. It seems to be running non stop. So I check the fridge door to check the seal. I see condensation around the outside edge of the fridge door. I do have the door clamped with 2 latches. It's seems to be very tight but who knows. Would I have a bad seal? What could I do to seal it better? Should I just make a door?

Also, I put the mini fridge on its side for maybe 5 minutes (maybe even less) but then it sat upright for about 12 hours before I plugged it in. I fear this could be my downfall. I've been reading what my problem could be but I wanted to ask my fellow homebrewers what your thoughts or experiences are?

 

[MrFoodScientist]

Well, it looks like you've doubled the space capacity of your fridge, but the cooling capacity is the same, so it could be that it's overworked. However, if you have condensation around the door, it sounds like your seal isn't perfect. It's hard to get it to seal against something that's not magnetic. Get some magnet strips to put onto the wood and then tape them over so they don't come off, make sure they stick to the magnets in your door seal first, though.

Also, what does the evaporator look like in your fridge after it's been running for a while? Is it all frosted up? If it's not frosted over, and it's been running for a long time, then I think you're out of freon. Is this an older fridge? How did you attach the collar to the fridge? Is there the possibility that you nicked a cooling line somewhere?

 

[snackson]

Try taking the cover off the freezer and installing a fan in there. That is the evaporator coil most likely and forcing that cold air into circulation will help. As mentioned above, the magnets being taped to the wood collar are a good idea to help keep the door sealed.

 

[Kmcogar]

It's not too old of a fridge. It worked before I added the collar just fine. I was using as a kegerator for 1 keg and it was good.

As for where I put holes in the fridge. They were on the sides but close to the edge of the front of the fridge. I put brackets to hold the fridge stable to the collar. I pre drilled every hole and didn't hit anything when I did that. The holes or screws in the fridge side of the bracket are kind of loose so I know they are only in the shell of the fridge and some insulation. They were short screws , so they did go far into it anyways. I'm not sure how much the magnetic strip will do but I'll give it a try. I have the door clamped pretty tight with some latches. I would say it's much tighter then it was before but like I said I do see condensation on the outside edge of the door. I'm gonna turn it on today before I go to work and let it run for a couple hours to see if the freezer part of the fridge starts to frost up. I'm also gonna stick something in between to door and the collar to see if I can get a tighter seal before I buy the magnetic strip.

Wish me luck!

 

[Kmcogar]

Try taking the cover off the freezer and installing a fan in there. That is the evaporator coil most likely and forcing that cold air into circulation will help. As mentioned above, the magnets being taped to the wood collar are a good idea to help keep the door sealed.

I did take the cover off the freezer and fun a fan in there. It didn't do much but I'm gonna try it again.

 

[Kmcogar]

Oh, also the freezer "was" frosted before I added the collar

 

[Kmcogar]

Ok, so I had the fridge running for 3.5 hours. I had it set to 3 on the thermostat. It's a 1-7 range. I'm not really sure how much it will effect it. The fridge was still running hot. I think it was running constantly since I left for work. The inside was about 60 degrees. The freezer compartment does have frost in it though so I am figuring it has enough freon. I'm hoping it's just the seal. I'm gonna pick up some magnetic tape or whatever. I might even make a door myself to seal it real tight. But I don't want to put too much money into it if it's not gonna work...I already put $40 into the build

 

[temple240]

What did you use to insulate the collar? Have you tried running the fridge at its coldest setting? I assume 7 is the coldest so I'm not surprised that it was 60 at 3. It really looks like you're pushing that little fridge too hard.

 

[snackson]

What is ambient temp? After 3.5 hours for it to be sitting at 60, is that with it empty or with kegs in it? If there are kegs, it's working as expected and it will take a little longer to cool it down. The outside of the fridge will be hot because that is where the condenser for the refrigerant is. That is moderate frost and I wouldn't worry about it. You more than doubled the space it needs to cool and it will take some time to get it down to temp. Hope any of this helps.

 

[Kmcogar]

Alright, I'm still gonna ensure the seal is good and then plug it back in, wait 24 hours and let you all know how it goes. Thanks again for the help

 

[Kmcogar]

Well, the fridge is still staying at about 55 degrees F on the highest setting while empty. It's keeps running but not cooling enough. I'm gonna check all my seals again. Hopefully it's only that. The fridge is cold inside, just not cold enough

 

[westo2]

Bigger fan and better sealing. The fridge works purely on convection, which is fine for the small space in a dorm fridge. When you've increased the space, the plate chills but without proper circulation you are going to have a hard time keeping up with the cooling load. I've got a ferm chamber made from a similarly sized dorm fridge with about 3-4x that space to cool. It never worked until I put a decent sized fan in place - I also set up a second fan that circulates air over the external coils to aid in cooling. The fridge is set to the coldest setting, and the fan and fridge are set up to a temperature controller, kicking them on at the same time. The combination allows it to hold lager temps.

 

[Kmcogar]

I'll try it. I'm gonna check all seals this weekend. And I'll put a BIG fan it in just to test it. I have a powerful AC fan in there now so it puts out some pretty good air flow but I'll try a bigger one.

 

[fpweeks]

My bet is that you nicked a line when you put screws into the metal skin.

I deconstructed a mini fridge for my kegerator and the lines are taped to the back of the metal skin. You could have hit one and never known it.

 

[broadbill]

Second vote for the overworked fridge. No way the manufacturer threw in a compressor capable of cooling double the volume of refrigerated space the unit came with.

Your best bet (IMO) at this point nix the collar and call it good enough, and start scouting Craiglist for a proper fridge. For what you spend in time and materials to build the collar, you properly could have been well on your way towards the cost of the nice used fridge.

 

[Kmcogar]

Time is irrelevant. I enjoy doing projects like this. I've seen another kegerator build where this fridge worked fine with a large collar. So I think it should be able to handle it. I havnt have up yet. I just can't put anymore cash into it. As you said $40 put into could have been put into a fridge but if you knew what I was working with you would understand I don't have the space.

https://www.homebrewtalk.com/f35/magic-chef-mcbr360s-kegerator-62910/index2.html#post642393

 

[broadbill]

Time is irrelevant. I enjoy doing projects like this. I've seen another kegerator build where this fridge worked fine with a large collar. So I think it should be able to handle it. I havnt have up yet. I just can't put anymore cash into it. As you said $40 put into could have been put into a fridge but if you knew what I was working with you would understand I don't have the space.

https://www.homebrewtalk.com/f35/magic-chef-mcbr360s-kegerator-62910/index2.html#post642393

The thing I need to point out with the thread you posted is we don't know how that type of build works 2-3 months after being built. Based on what you are observing, I would guess alot of them end up on the scrap pile after finding out they can't cool double the volume (or more) of space they were intended to.

By all means, if you enjoy this sort of thing have at it! It's your hobby. I guess my focus here is so the next guy to come along who whats to build one of these things has a realistic idea of what is involved and that it probably won't work all that well, at least if your experience is any indicator.

 

[Kmcogar]

Well this will be good good thread to follow then I guess. "What not to do" I will be sure to post details of everything. If I can't get it to cool the entire chamber, I will take off the collar then put the fridge the way it originally was and see if it still works. Who knows, I maybe have bumped something and broke it. I'm just saying I wouldn't rule out the possibility of a mini fridge working in a bigger chamber. But only time can tell....

 

[MrFoodScientist]

With how frosty those coils got, you definitely have enough freon. I've had mine get pretty hot on the outside when trying to cool a warm keg. That is a lot of thermal mass to try and get down to temp. If you're worried about it overheating, put a chilled keg in there and see how it does, or a put a couple blocks of ice in there to sort of "jump start" it and see if it will get to the point where it will hold temperature and kick the compressor off. If that's not happening, next thing I'd check is where the probe for the thermostat is. It should be basically clamped onto the evaporator, if it got knocked loose, that would explain it running longer than expected.

Temple240 had a good question, what did you insulate it with? It looks like it's just aluminum tape over the wood. If that's the case, you do need some better insulation. 2 in thick pine on a good day will only insulate about as well as 1/2" styrofoam. If it were me, I'd throw some 1 inch thick foam insulation in there so you can have roughly the same R-value as the rest of the fridge. (R-value for Wood is about 1.5 per inch of thickness, rigid foam insulation is about 5 to 6 per inch, and I believe mini fridges are estimated at 6 to 10)

Other than that I think you're on the right track looking for a better seal. If you have access to some dry ice, put a small amount of dry ice in an open jug of water inside and then shut the door. You should be able to see any air leaks, though by doing so, you will be creating positive pressure on the inside, so you're likely to see more leaks than you really have. It will at least give you an idea of where your seal might not be as tight as it should be.

 

[Kmcogar]

MrFoodScientist, awesome idea! I'll def find some dry ice somewhere. It can't hurt at least. And your right, I only have the wood as insulation. I guess I light have to pick up something else. Even though it's not well insulated I think it would still get cold though. Unless there is a leak. I'll test on it some more this weekend

 

[mattd2]

MrFoodScientist, awesome idea! I'll def find some dry ice somewhere. It can't hurt at least. And your right, I only have the wood as insulation. I guess I light have to pick up something else. Even though it's not well insulated I think it would still get cold though. Unless there is a leak. I'll test on it some more this weekend

Unless you grab the dry ice with you bare hand
I would suggest maybe getting rid of the wood collar and just build one out of 2" rigid foam insulation, if it is the stuff I think it is and the dimensions stack up you might be able to just sit the foam box on the floor and place a 1/8" piece of plywood on top to distribute the keg(s) weight

 

[jpaulr]

If you need the space on the inside, you can just add a layer of foam outside the wood collar. That should work the same way as foam on the inside. I don't know what the long term effects of sandwiching a layer of wood between foil tape and foam are, but it'd be a relatively easy way to test if insulation is your problem.

 

[Kmcogar]

Jpaulr I like that Idea too. But it might look ugly as.....anyhow. I'm gonna check my inner dimensions and see if the kegs will fit if I put more insulation in

 

[Ki-ri-n]

To get a good seal, use a flat piece of galvanized sheet stock for HVAC. Use that around your opening and cut an "X" where the door goes. Fold the flaps to the inside leaving a metal frame around the opening. The mag strip on the door will now have something to seal too. I used roofing nails to fasten it to my extension.

 

[Kmcogar]

For those of you who helped out and or care. I insulated the inside of the collar with 1 inch Insulfoam. R value of 3.8 I believe. I'm not sure what the r value of a 2 x 4 is but it was not enough.

Now that I added the Insulfoam, it's cooling perfectly. I'm really excited it's working fine now. I would have been pissed ifi spent all that time and money and it stopped working. But all in all the fridge is cooling great! I can fit 3 corny kegs in it too! Now I need to make or buy a 3 tap tower....

On to the next project

 

[Brumateur]

Kmcogar,

I can't see clearly on your first picture but it looks like you put back of your freezer in closed compartment. If so make some holes and even add a fan. Coils at the back should be well cooled by ambient air.

 

[Brumateur]

.

 

[Kmcogar]

I actually removed the freezer door and I do I have fan too

 

[Brumateur]

Do you have fan blowing to hot coils located ouside fridge (on the back )?

 

[Kmcogar]

I don't right now. I'm a little low on sockets to plug into though. But like I said, it's working now. Of it continues to stay hot I'll throw a fan on the outside too somehow