Haier kegerator modifications, upgrades, etc...

[Gasp100]

Against my better judgement I appeased my wife going for a cheap unit (Haier Brewmaster, SS door). Someone on ebay was selling these as fridges only (I have more than enough high quality gear -- dual CO2 guage, Ventmatic faucets, etc... from previous kegerators). I was going to use my Johnson Controls thermostat unit to get the temps I need and try and bypass the temp control the kegerator uses. So I got it all hooked up, ran the Johnson controls into it and I also built a 12V computer fan/hose assembly for the draft tower. I set the temp control on the Haier to it's coldest setting, then figured the Johnson Controls temp regulator would do it's thing. I guess the setting on the Johson controls was actually too cold, I ended up with a pretty thick layer of frost on the cold plate in the back of the fridge in just one night and a thin layer of ice in on the top of a quart container filled with water.
So, I decided to take the Johnson Controls temp regulator out of the equation to see how the kegerator's built in thermostat does on it's own. I did the thermostat mod (taking apart the unit and turning the set screw -- I turned it only one full turn -- and setting the control to NORMAL). Can anyone confirm that you turn the screw CLOCKWISE for colder? I've seen several threads where people state you turn it counterclockwise, but this is directly from a Haier bulletin that was released and posted on another thread:

Solution:
1. Disconnect unit from supply.
2. Remove thermostat from housing.
3. Locate thermostat calibration screw on top of thermostat (see Diagram 1)
4. Adjust the calibration screw to reach desired temperatures:
a) For Cooler Settings: Turn upper adjust screw one full turn clockwise
(360 degrees), which will offset thermostat 3 degrees colder. b) For Warmer Settings: Turn upper adjust screw one full turn counter
clockwise (360 degrees), which will offset thermostat 3 degrees
warmer.
5. Remount thermostat in housing and onto back of the cabinet.
6. Plug the unit into the power.
7. Set thermostat to NORMAL setting.
I defrosted the fridge and I had built a 12v computer fan / fan box / hose run up into the dual faucet tower as well. The faucet tower is mounted on my bar top and I have a piece of PVC where the lines run through in between the top of the kegerator and the bottom of the bar top. I guess I will need to make sure that no air can get into there?
Here are my questions:
1. how should I be taking temps using a liquid thermometer? Right now I have a quart container filled with water, I'm going to check it tonight when I get home. I assume checking the actual temp of the beer in the glass is best, although it's okay if it get into the 40-44 degree range imho.
2. How much frost is a "normal" amount for this Haier fridge on the cold plate? I was alarmed to see any frost at all, but after reading some posts it looks like "some" frosting is actually normal and okay. I thought this was a self-defrosting unit, but I guess it's not that efficient?
3. I've seen mention with these particular models that people are building fans to blow the cold air down? I definitely can't fit two blowers in this thing, so I'm wondering which is more important, blowing cold air via hose into the draft tower, or blowing cold air back down within the kegerator itself?

I have a party coming up this weekend, the 1/6 keg of Stoudt's Pils is in another fridge until the new configuration is tested. I'm just concerned about the frosting on the cold plate, but it sounds like that is actually okay?
Thoughts?

[Gasp100]

Hmmm... in another post I had explained that I had this Johnson controls thermostat and someone mentioned it probably would not do any good because the fridge's own thermostat will take preference. But I don't think that is correct, seeing this is actually an "over-riding thermostat" it should take preference. I'm going to add it back into the kegerator configuration, but this time I will err on the side of caution and set it to around 38 degree's. I think the initial time I set it to like 32 degree's and that was way too low.
Anyway, this has worked really well with a standard fridge in the past when I used to home brew and lager:

Johnson Controls Refrigerator Thermostat

I figure with the thermostat "fix" the Normal setting should be able to get me close to my 34-38 range. Then with the Johnson in the loop, I should be able to dial that in a bit more; I am more confident in the Johnson temp controller unit than the thermostat that comes with the kegerator. I guess I will have to just tweak until I find the perfect mix of coldness, pour and minimal icing on the cold plate.

[cubby_swans]

If your kegerator gets cold enough (sounds like yours does), and you are simply trying to more accurately control the temperature, then the temperature controller will work just fine.

When someone said the temperature controller would do no good, they probably assumed that your kegerator was unable to cool properly, as is often the case with the cheaper kegerators (before any mods are done). In this case, the kegerator temperature problem needs to be resolved (which you have done) or the kegerator temp sensor needs to be bypassed.

[TomK]

Okay, Gasp, no one can accuse you of not providing enough information... and if Cubby read all that, well, then I'm going to too, but man...

I'll be back in a few...

[TomK]

Those external controllers work like a light switch, turning the power to the fridge on/off per the setpoint on the controller's dial. They depend on the fridge being able to reach a temperature, when it is on, at least as low as the desired temperature set on the controller. In other words, if your fridge can only go as low as 40 degrees, then no matter how long the compressor is told to stay on by the external controller, it will not reach a temperature below 40 degrees.

"I assume checking the actual temp of the beer in the glass is best, although it's okay if it get into the 40-44 degree range imho."

Yes, you want to find the actual temp of the beer in the glass (2nd pour), but no, 40-44 degrees is not good: FOAM CITY!

[Gasp100]

Thanks guys, I guess I misunderstood exactly how these external temp controllers work although they are quite simple. So basically, my kegerator (with or without the mod I guess) is able to get cold enough. But because I want to avoid the huge swings in temp (up and down) that these are notorious for, the external temp controller usage makes sense. If I set it at 37 like I have it now when the internal temp of the kegerator gets to 41.5 (3.5 degrees above set point) the compressor should kick in and get the cooling down to 37. Likewise if the temp gets down to 33.5 degrees the temp controller should STOP the compressor if it's on so it doesn't get too cold and freeze up the back plate.
So, it's looking pretty good as of this morning. After the main manual defrost I did I noticed some light frost when it got down to correct temps. I then put in the external thermostat controller and checked it a few hours later and the back plate was frost free. Now, I checked it again this morning and the back plate had a thin layer of ICE (ie. NOT frost) on it; but I'm assuming that will eventually defrost (or really just melt if the external controller is literally turning the fridge on/off). I will check it again tonight. The faucet tower actually feel pretty cold to the touch as well so I think the draft cooling setup is working okay.
Now, I've had a quart container of water in there and everytime I check the temp is around 42 degree's. When I pour a draft (just put on a sixtel of Stoudt's Pils, in my experience Pils usually have a more pronounced, frothy head compared to most ales) into one of those specially shaped Sam Adams beer glasses, the head is about 3/4 - 1" and glass itself hazes up on the outside from the cold beer and it tastes pretty damn good <note, I usually like to let the keg sit for at least a day or two before making a final decision on quality of draft>. That's the first pour, so things are looking good. The second pour has a little less head, still nice lacing in the glass, maybe a little tiny bit colder.
BUT, the temps still read about 42 degree's...
My guess is that the internal keg beer temp is probably around 39 degree's and I'm picking up some warmth traveling up through the lines, through the bar top, through the draft tower. I think it's a good serving temp; even the first pour is more than drinkable, not too foamy at all. NOTE, my PSI is around 8 which is a tad less than I used to use ~10PSI.
My main concerns are freezing up of the cold plate, losing correct and even temps and working the kegerator too hard so it burns out. I think I'm in a good place for right now, I may ditch the tower fan and use it soley for air circulation within the kegerator but that depends on how much icing/frost I get on the backplate over time. We shall see... I'm thinking about picking up a sixtel of Victory Festbier tonight to load up the kegerator and get both faucets serving
This site is a Godsend BTW; Thanks all!

[KillianBoy]

Gasp100,
I really don’t want to open a whole new can of worms or accuse you of doing anything wrong just trying to get a handle on your problem.

1. Are you sure the Haier you have is meant for built –in cabinets? From the manual and web site the only model they carry is meant for free-standing only. Check the manual that came with unit and check under safety precautions. I know there are pictures showing it in cabinets but I don’t think it was meant to be enclosed. If it is meant for built-in cabinets, then go to question 2. If it does says it wasn’t meant for enclosed places and you still want to use it in cabinet then search under built or cabinet in forum there was a bunch of guys who had the same problem.

2. Is the sensor probe in or out of water? Some members have found that probe in water have caused ice to build because the compressor doesn’t turn off (water doesn’t have enough temperature swing to cycle compressor).

3. Are you sure the unit is sealed? Either door seal or where you have tower extend to counter might have an air leak (probably the PVC tower extension). I’d try to seal the area you extended to beer tower. You may have to insulate tower/PVC better. The heat coming from evaporator from back of unit might be getting to PVC pipe. Pictures or better explanation on how you connected beer tower to unit might be needed.

4. Are you sure your fan is working properly? Properly working fan system will take cold air from bottom to shank/faucet and then return slightly warmed air to unit. Check the flow coming from tower if too hot then you may have to insulate, if not enough air flow, you have to redesign system. Check flow of air by using a piece of paper by fan if drawn toward fan then fine if away then not working properly.

Most guys that used an external temperature controller on a Haier, just set the thermostat to the maximum and let the external do all the work.

The defrost cycle on a Haier is basically the off cycle of the compressor, when unit is off the ice will melt, on it won’t. So if compressor won’t turn off, ice won’t melt. I’d also stop opening the door too often, the more you open it, and the more moisture gets in. You have to monitor the on/off cycle of compressor, it might not be cycling properly because of the above.

If the compressor cycles properly (should be on x minutes then off x minutes) and you still have ice build up. Then you may have to turn off several hours a day to melt ice, turn off unit after drinking or maybe in the morning, other have used a timer to force defrost unit in early morning hours.

KB