Frost Free brewing fridge problem

afromaiko · Post by **afromaiko** » Sunday Dec 10, 2006 3:37 pm

Hi,

I recently acquired a frost free Westinghouse 410ltr bottom mount fridge for brewing in. I'm just running through a testing phase with a Fridgemate external thermostat before brewing in it.

I noticed a problem that the fridge sometimes switches itself off, even when the Fridgemate is attempting to power it. I guess this is to do with the frost free feature. Problem is, its really hot here at the moment, and the temperature inside rises about 5 degree when this happens.

There is a small timer knob on the back, right down near the compressor. I think this is for the frost free phase.

Are there any fridge experts here that can advise me what the best way to sort this out is? Is anyone else out there using a frost free fridge successfully as a brew fridge?

I'm wondering if its possible to disable or bypass the frost free module and what effect this would have on the reliability and life span of the fridge.

thanks

r.magnay · Post by **r.magnay** » Monday Dec 11, 2006 6:56 am

afromaiko,
The timer can be dissabled quite simply, but at the risk of being howled down for suggesting you should use a sparky, get a sparky!!! (Or a fridgy) The timer simply turns the compressor off and some heaters on for a short time to defrost things, by removing the power to the unit and ensuring that it is not in the defrost mode, your problem will be solved.

afromaiko · Post by **afromaiko** » Monday Dec 11, 2006 9:33 am

Thanks, I also found this interesting info about defrost timers & frost free fridges:

http://www.appliance411.com/faq/howdefrostworks.shtml

The model I'm using is a fridge/freezer combo with the freezer on the bottom.

Although the fridge temp is running higher than normal using the Fridgemate, the freezer section is still showing usual freezer temps of around -20C (with variation when the defrost timer kicks in).

Since the evaporator coil is in the freezer section so I'm guessing that would be just as prone to icing as if it was running as usual. Rather than fully disabling the timer I might wire a switch in and see how things go.

afromaiko · Post by **afromaiko** » Monday Dec 11, 2006 11:58 am

Just thinking about this some more...

With Fridgemate controlling a frost-free fridge, rather than plugging the fridge into it and switching off the whole unit each time would it be better to disable the fridge's own thermostat and run the wires that usually connect to that instead to the relay switch on the Fridgemate?

That way it should keep the temp more stable by allowing the defrost cycle to come on properly and to allow the freezer section to keep functioning normally too. Might even be able to keep perishables in there, since our normal house fridge-freezer is tiny.

The thing I'm finding is that since my defrost seems to be on a timer, if the defrost cycle happens around the same time that the Fridgemate reaches the set temp, the fridge will be off for a prolonged period and additionally heated up even more by the defrosting heater coming on too.

I haven't tried putting a full fermenter in there yet, and this may help to regulate the internal temperature somewhat. Are these frost-free cycles causing problems for anyone else with external thermostats?

morgs · Post by **morgs** » Monday Dec 11, 2006 1:01 pm

How long does the temp for before it starts coming back down? A five degree difference on a fermentor full of beer especially plastic is only going to have a minute effect on the beers temp over a short period of time. I really wouldnt be too concerned.

morgs · Post by **morgs** » Monday Dec 11, 2006 1:02 pm

sorry how long does the temp rise?

alangman · Post by **alangman** » Monday Dec 11, 2006 2:18 pm

Hi Guys,

My guess it that the changes in the air temp during defrosting won't affect the temp of the beer in the fermenter. Liquids take a long time to warm and cool compared to gases (ie air). Look at it this way, have you ever gone to the fridge to get a drink, had a sip and then said " Damn, this is warm, the fridge must be in defrost mode!"?

If you are still concerned, you can test this theory. Get a bucket of water and put it in the fridge and put a thermometer in it. Wait 24 hrs and then check the water temp. We'll call this the baseline temp. Then, next time you notice that the fridge is "warm" (ie in defrost mode) check the water temp again. I'd be very surprised if there was more than a degree different. Further, the more water/beer that is in the bucket/fermenter, the slower the temp will change.

In short, there should be no problem at all using a frost free fridge. Good luck and enjoy you brewing

Cheers,

Adam L

drsmurto · Post by **drsmurto** » Monday Dec 11, 2006 2:22 pm

I am in the process of saving for a beer brewing fridge and from my readings was under the impression that you should avoid the fridge/freezer combo? I was/am planning on getting an old fridge that doesnt have a freezer compartment so as to avoid all these issues.......

afromaiko · Post by **afromaiko** » Monday Dec 11, 2006 2:40 pm

I'll put a fermenter full of water in there for a few days and monitor the temperature.

Not sure how long it took to come back down yesterday, but at anytime there is going to be a chance of least a 30min delay before the compressor kicks back in should a defrost cycle happen around the same time as the compressor delay ends (9mins delay + ~20mins defrost).

I think the defrost cycles are usually every 8 hours of accrued time the fridge has power supplied to it.

morgs · Post by **morgs** » Monday Dec 11, 2006 2:46 pm

Put a fermentor full of beer in there quick smart. Brewing may be for some a science but mate seriously it aint going to make a difference.

If only i could have this problem, as i have no room for a spare fridge. doh!

afromaiko · Post by **afromaiko** » Monday Dec 11, 2006 2:59 pm

drsmurto wrote:I am in the process of saving for a beer brewing fridge and from my readings was under the impression that you should avoid the fridge/freezer combo? I was/am planning on getting an old fridge that doesnt have a freezer compartment so as to avoid all these issues.......

The reason I went with this fridge/freezer was because it fridge on the top and is much easier on the back for lifting full fermenters in and out. Also no compressor hump like standard combos gives a lot more room. I did look at perhaps getting a fridge only model, but there isn't many of them going round unfortunately. I got this one for $160 and it's 410ltr in total, 10 years old and runs well.

Biggles · Post by **Biggles** » Monday Dec 11, 2006 4:21 pm

Just dont bother using the freezer part at all while brewing beer and let fridgemate handle the temp control. If the auto defrost is after 8hrs running, it wont cause any trouble at all.