Brew Fridge Advice Wanted

[Juzz]

usually a reader but this is my 1st post so here goes...

I have a working 420 L Fridge (no freezer) that I am going to convert to a brew fridge with a new thermostat and a digital thermometer. Before I started anything I thought I would ask if anyone with relevant experience or knowledge has any lessons learned, hints or tips that they could share with me so I dont have to redo it again in a few months. Any advice would be appreciated.

 

[Mitternacht Brauer]

usually a reader but this is my 1st post so here goes...

I have a working 420 L Fridge (no freezer) that I am going to convert to a brew fridge with a new thermostat and a digital thermometer. Before I started anything I thought I would ask if anyone with relevant experience or knowledge has any lessons learned, hints or tips that they could share with me so I don't have to redo it again in a few months. Any advice would be appreciated.

My advice would only be to switch it at the thermostat contacts and not the main supply so you dont mess with the sump heater (Lengthern the life of the compressor) . I have aquired a similar fridge last week and will do the same as the lager Im doing at the moment is getting too warm .

 

[Yorg]

My advice would only be to switch it at the thermostat contacts and not the main supply so you dont mess with the sump heater (Lengthern the life of the compressor) . I have aquired a similar fridge last week and will do the same as the lager Im doing at the moment is getting too warm .

Can you say a little more about this, for those not so electrically experienced?

 

[OSF]

usually a reader but this is my 1st post so here goes...

I have a working 420 L Fridge (no freezer) that I am going to convert to a brew fridge with a new thermostat and a digital thermometer. Before I started anything I thought I would ask if anyone with relevant experience or knowledge has any lessons learned, hints or tips that they could share with me so I dont have to redo it again in a few months. Any advice would be appreciated.

Hey Juzz,

I don't have any specific advice other to say that I recently converted a fridge to a brew fridge using a "FridgeMate". It works really well and I am really happy with it. If I want to brew at a warmer temp (e.g. currently doing a Ginger Beer at 25degrees) I use a heat belt on the fermenter with the FridgeMate and if I want to brew at a cooler temp (e.g. I just did and Ocktoberfest at 12 degrees) I plug the fridge into the FridgeMate (pictured). If I ever want to use the fridge as a normal fridge I will simply unplug the FridgeMate.

The only additional thing I have done is make a thermowell for the temperature probe to get it right into the middle of the fermenter. I got my local SS welder to weld shut and polish the end of a keg dip tube and the probe goes inside this. The one thing I have found which may be of interest to you is that the temperature difference between the inside of the fridge and the wort in the middle of the fermenter can be several degrees. As such if you can get the temperature probe into the middle of the fermenter rather than just in the fridge I would recommend it.

With the temp probe in the middle of the fermenter and using the FridgeMate I have been able to keep the temp of the fermenter to within 1 degree of what I set it at.

 

[matti]

I didn't want to muck up my fridge as I have limited space and time and the noggen work a bit slow at times.

I've got an old Kelvinator fridge and use a fan control thermostat. You can get these from these guys and other outlets like G&G around $80-140.

A bit expensive but they leaves nothing to do,
You secure the thermostat probe to side of fridge and plug the electrical cord from fridge into dial unit.

It has no digital unit so it might be worth checking the temperature with a $2 thermometer in fridge for accuracy.

 

[Juzz]

I was planning on using a stainless steel probe, to take temp measurements, inserted into the wort (through a sealed hole in the lid of fermenter). I was also planning on wiring my heatbelt into the thermostat and turning off the fridge for when I want warmer brewing temps.

It looks as if the 'FridgeMate' will do exactly what I am wanting to achieve (without the effort ) Are they expensive? Easy to install? Any downsides? Easy to get? What else should I know about them?

OSF - your pic makes it look so easy

Appreciate any advice

 

[matti]

fridgemate thread

 

[sanders4_]

the fridge mate will only control a temperature within 3 degrees. For example, if you set the fridge mate at 18 degrees, it won't turn on the fridge until it passes 19 degrees, and then the fridge won't be turned off until it hits 16 degrees. Thats the one thing i found REALLY lacking with the fridge mate.

Also, i bought one about a year ago, and its no longer working... but i haven't read about anyone else experiencing such a short life span. For ease of use, they get my thumbs up, much cheaper than ESB (WAY to expensive for what you get). No idea how you would 'wire one up to the thermostat contacts', so i would just go with the mains plug, everyone does it with no dramas.

Good luck dude, really doesn't need much electrical savy.

 

[Doogiechap]

the fridge mate will only control a temperature within 3 degrees. For example, if you set the fridge mate at 18 degrees, it won't turn on the fridge until it passes 19 degrees, and then the fridge won't be turned off until it hits 16 degrees. Thats the one thing i found REALLY lacking with the fridge mate.

G'day Juzz,
One big vote for the fridgemate. Here is a piccy of the specs (which give a temp differential of 1-15 so you can dial in your ferment temps pretty accurately.) Buster has a vaiid point about utilising the original thermostat connections if your fridge does have a sump heater.
Cheers
Doug

 

[OSF]

the fridge mate will only control a temperature within 3 degrees. For example, if you set the fridge mate at 18 degrees, it won't turn on the fridge until it passes 19 degrees, and then the fridge won't be turned off until it hits 16 degrees. Thats the one thing i found REALLY lacking with the fridge mate.

Also, i bought one about a year ago, and its no longer working... but i haven't read about anyone else experiencing such a short life span. For ease of use, they get my thumbs up, much cheaper than ESB (WAY to expensive for what you get). No idea how you would 'wire one up to the thermostat contacts', so i would just go with the mains plug, everyone does it with no dramas.

Good luck dude, really doesn't need much electrical savy.

Sanders4 does have a bit of a point. My last brew was an Ocktoberfest and I set the fridgemate at 12 degrees (with a 1 degree differential). The fridge is sitting out in the shed and the temp varies greatly during the day and night (i.e. by a whole stack). Checking the fridge regularly however at different times during the days and nights, I never saw a temperature reading less than 11 degrees or greater than 13 degrees. Perhaps at worst case scenario it might have gone from 10 to 14 degrees but I never saw this (and even if it did I am ok with this).

After having very poor temperature control previously, I am however now very happy with this setup. Currently I have a heat belt around a Ginger Beer and am doing it at 25 degrees (this temp may be good or bad, but we can leave that to another forum!!). Checking the shed as I call it, (or - Are you having another beer as the Fiancee always asks) over the last week I have only seen the temp at 25 or 24 degrees.

So all in all I am very happy with it.

Cheers
OSF

 

[KGB]

For ease of use and if you don't want to go re arranging the electrical components of your fridge I'd vote for the fridgemate. I was using mine for heating brews during the winter, right now I'm using it to keep my brew fridge at about 20 degrees for the current brew. nice and easy to use, follow the thread in the link posted by Matti if you want to know more or have any probs.

 

[sanders4_]

Just out of curiosity, how would one tell if your fridge/freezer has a sump heater and needs to be switched at the contacts, i'm interested in finding out more about this.

 

[Yorg]

Just out of curiosity, how would one tell if your fridge/freezer has a sump heater and needs to be switched at the contacts, i'm interested in finding out more about this.

Yes, me too. Please explain the issue and what you do exactly re connection/wiring.
Thanks.

 

[Doogiechap]

G'day chaps,
I asked my Dad who used to work on domestic and commercial refrideration and he said :

"Sump heaters were confined to large sealed compressors to stop the accumulation of liquid refrigerant in the sump and excess condensation on the exterior as the liquid slowly boiled during the off cycle which used to be a real problem in some large air conditioning units. This is experience from my youth but I have noticed more things have changed now apart from white hair. In recent years the drive for energy conservation will have made most manufacturers of domestic equipment find other alternatives. Dont be surprised by things you see made by LeMair (or La Dung) and Korea is not known for good domestic fridges."

So whilst we can't rule out the possibility of sump heaters they are certainly not common.
Cheers
Doug
PS Some fridges have a wiring diagram on the back so you may be able to identify the heaters existance from that too

 

[SJW]

I dont want to get anyone off side now but........ I think there is no need to get all excited about getting the probe into the wort or even the centre of the wort. I did a lot of testing with this and came to the conclusion that it makes very little, if any, diff.
My finding were that with the probe in the wort, the time it took the wort to cool down to the desired temp and the fridge to turn off the wort got a little cooler than expected as the air out side was still colder than in the wort and the wort on the outer part of the fermenter was cooler than the wort in the centre.
Now the opposite thing happened with the probe in the air, outside the fermenter. i.e., the wort was a little warmer than the desired temp as the probe cuts the fridge when the desired temp is reached.
Conclusion- For all the hassle of making a thermo well and having another thing in the wort and sealing it, its just as easy to leave the probe in the air and dial the temp down 1 or 2 deg C.
Also I found that fermenting wort is not that much warmer than fermented wort.
And as for the comments about the 3 deg. differential. Unless u want your fridge going on and off every 10 seconds this is more than fine. The wort does not change temp that can be measured with this 3 deg diff.
So chill out....its only beer.

Steve

 

[sanders4_]

I suppose i should qualify my rant. I agree that 3'C isn't a concern when you only need to chill OR heat.

Where my fermentation fridge is, I need a heat source at night, and a chilling source during the day. With two fridgemates, one heating AND one cooling, the fridgemate not stopping until 2'C past the set temp becomes a real problem for me. So the heat source and fridge don't end up fighting with other, they need to be set far enough apart, at least 2'C apart, experience showing 3'C separation works best.

Example: If i want to maintain 18'C (with only 2'C separation between the controllers)

Set the fridge controller to 19'C (turning on above 20'C, off at 17'C).

For the heater controller, set that to 17'C (turning on below 16'C, off at 19'C)

So the tightest range i can control is >16'C and <21'C. With 3'C separation between the controllers, the temp can range 6'C around the target temp.

I didn't realise this when i bought then, as it said the differential was 1'C, the specifications (that doug kindly supplied) clearly states 1'C.

This might not be such a problem on the Newcastle, where temps tend to be more stable between day and night, but in Canberra, it can be 34'C during the night and below 10'C at night.

I've since built a temp controlling circuit that, using a target of 18'C will chill above 19'C, stopping at 18'C and heat below 17'C, stopping at 18'C. The fridge doesn't turn on more than once every hour, and then its only for a brief time. Gives much finer control that i'm completely happy with.

Like you said, 3'C is no big deal