Temp Control Questions

[Koikaze]

Hi guys,

Now I'm trying to get some constant temp control for my brew. I have gotten myself a cheap fridge. And wondering if i should buy and install a Fridge Mate MKII. I would like some advice if anyone has some to offer. Should I get a temp probe too?

Also wondering how it is to install... is it easy?

 

[schooey]

Fridgemate's are probably the easiest solution for what you are trying to do. Do a search on here, you will find a world of info on what you need to do to build it/use it etc..

 

[white.grant]

Doesn't get much easier than a fridgemate. Even I could do it. I used the instructions found here http://helms-deep.cable.nu/~rwh/blog/?p=29

 

[wyatt_girth]

fridgemate is very user friendly and not that difficult to set up either.

 

[mckenry]

Hi guys,

Now I'm trying to get some constant temp control for my brew. I have gotten myself a cheap fridge. And wondering if i should buy and install a Fridge Mate MKII. I would like some advice if anyone has some to offer. Should I get a temp probe too?

Also wondering how it is to install... is it easy?

It comes with a temp probe. I blue tac'd mine to the outside of the fermenter. So easy to install. I now have two. One set in 'cooling' mode - to control a fridge and the other set to 'warming' mode to control a heat pad. So now, its ales and lagers all year round - No matter what the weather!
You'll never look back. B)

 

[Koikaze]

Thanks Guys.

Oh is it installed in the middle of the extension cord? I'm not quite getting the picture here... if the prediction is right and it does go in the middle of the extension cord, does the temp probe just get stuck through the door of the fridge?

 

[gruntus]

Oh is it installed in the middle of the extension cord?

Depends on where your powerpoint is and where you want to mount the fridgemate. Spend an extra 50c and get a 4m extension lead...cant go wrong.

does the temp probe just get stuck through the door of the fridge?

I wired mine through the existing whole in the back of the fridge....mine was a cheap russian made bar fridge. Anther options is to drill a whole though the side/back and then use bluetac to fill the gap

The fridgemate is so simple to setup and use....pilsners in summer....you cant beat it.

 

[Screwtop]

Oh is it installed in the middle of the extension cord?

Yes

The fridge thermostat is set at coolest and the fridgemate goes "inline" so to speak, between the powerpoint and the fridge plug, switching power on and off to the refrigerator as required.

does the temp probe just get stuck through the door of the fridge?

Run the probe lead in over the door seal on the hinge side of the fridge door, I find it best to tape the lead for a little way to the outside of the fridge and and to the inside of the fridge leaving enough of the lead and probe to be able to position it on the side of a fermenter in any position inside the fridge.

Don't drill holes in your fermenting fridge, not modifying the fridge is the whole idea behind using a fridgemate. It's transportable from fridge to fridge or freezer, and as your needs change you can change fridges etc and still have a useful normal fridge/freezer to sell, trade or keep or whatever.


Hope this helps,

Screwy

 

[Koikaze]

Thanks heaps for the clarification... i'll order one very soon

 

[paul_h]

If you're going to control the temp of the fridge with an air probe, it's better to put the end of the probe in a jar of gylcerin. Too many stops and starts by small air temp variations shortens the lifespan of a fridge, especially ones without start capacitors.
Measuring the steady temp change in a liquid sample rather than air temp will more accurately cycle the unit as you are cooling the fermenter, not the air. Ie the fridge wont turn off when the air has reached the set point, but run a little longer to get your beer down to temp, less starts, longer runs.

 

[Sprungmonkey]

Why gylcerin and not just water?

 

[paul_h]

Why gylcerin and not just water?

Water normally stuffs the probes up after a while with corrosion.

 

[Koikaze]

hhrm thats a good idea. I might look into this. It seems to be working ok so far. (I hooked it up yesterday) but its too bloody cold in vic anyway lol

 

[etbandit]

Water normally stuffs the probes up after a while with corrosion.

Is the thermal capacity of glycerin and water the same?

I would have thought that glycerin would remain colder for longer compared to water (and beer) and therefore throw the thermostat off when it should turn the fridge on and off.

?

 

[paul_h]

All the hospitals that use this method to control temps in all liquid fridges, ie blood fridges and they have to be right on the money for the product temp in the fridges. I'm just suggesting this in stead of having the air probe loose in the fridge, if it's attached to the fermenter leave it like that.
I know beer that's brewing is exothermic, so there's never going to be accurate control of the beer temp anyway short of putting a probe into the beer. I'm just thinking of all the short cycling that could occur on a domestic fridge not designed for it and the possible damage to the compressor.
When you look at how fridges are normally controlled, it is be return air temp in fan forced (not random space temp somewhere inside the fridge), or cold plate thermostats on cyclic defrost. No fridge is designed to control temp with a temp probe dangling around in the middle of it.
I
edit: f you attach your probe to the fermenter, fine. But if not, in a jar of another liquid is better than using a random air sample.

 

[KGB]

Hospital fridges would be opened and closed a lot more than a brew fridge would be, so the air temp would not be a reliable method when using a probe. In a brew fridge which should remain closed most of the time its not so much of a problem. In any case, a fridge mate has a compressor delay function, which is recommended to be set at ~9min to prevent exactly the type of on/off burnout you are talking about.

 

[etbandit]

Hospital fridges would be opened and closed a lot more than a brew fridge would be, so the air temp would not be a reliable method when using a probe. In a brew fridge which should remain closed most of the time its not so much of a problem. In any case, a fridge mate has a compressor delay function, which is recommended to be set at ~9min to prevent exactly the type of on/off burnout you are talking about.

What is the compressor delay? Just got a new fridge with this function and don't know what to set it to. Its currently on default 2min.

I assume its the length of time the compressor waits, before starting refrigeration once the set temp is reached?

If so, would you not want refrigeration to start immediately once the temp is reached eg 10C for lager fermentation? The temp could go up to 12C or 14C during the 9 min delay.

 

[MCT]

The temp could go up to 12C or 14C during the 9 min delay.

No it wont, fridges are pretty well insulated.