Temperature Controllers

[wulfsburg]

Hello. SWMBO just bought me a brand new fridge for my birthday. Awesome gift. I had a keezer that broke. I was using a temp controller to keep it from freezing. I am not sure if I need to add that temp controller to this fridge or not, but if the fridge will not get as warm as 65 degrees on its own, is there any potential for damage from using a 3rd party temp controller switch?

For those times (namely this time of year) where the temp is just too hot in the house, I need to sue the fridge for fermentation. I used it on my keezer, but it was a cheap used hunk of crap that lasted a year for 50 bucks. This is a 500 dollar fridge and don't want to end its life pre maturely.

Perhaps a refrigerant/appliance expert can shed some light on this?

Thanks

 

[Jdk261]

I wouldn't. The controllers are basically short cycling the compressor to maintain temps. Just go get something cheap on craigslist.

 

[wulfsburg]

I appreciate your input and opinion. Anyone else ?

 

[MalFet]

Refrigerant/appliance expert I am not, but most of the better temp controllers have both a deadband and cycle timer to prevent quick ons and offs.

Make sure that your fridge will even work with a temp controller, though. Many higher end fridges are computerized and likewise can't be controlled with simple on-off adjustments.

 

[basilchef]

there is a cheap thermostat on learntobrew.com you plug your fridge into the therm then into the wall. i cant imagine its very dangerous for your fridge. but i dont really know.

 

[wulfsburg]

there is a cheap thermostat on learntobrew.com you plug your fridge into the therm then into the wall. i cant imagine its very dangerous for your fridge. but i dont really know.

Well, here is the thing. I have been googling to find out if there is anyone who can speak to this, but I can't seem to find any evidence or a site claiming that using a traditional power cut of is harmful or not. Normally I can find a good response on this site.

My thinking is this, the compressor runs at 1 speed. On and off. If it is cut off by means of just cutting the power to it, I cannot seem to fathom that it would do any damage to the compressor. Especially if I set it for a 5 degree variant , so its not kicking on so much.

Last night I turned the fridge off on its built in temp controller and it went from 46 to 75 in about 12 hours. SO figuring it only probably takes it a few minutes to cool to 65, I would set it on 65 and have it kick on at 70.That is 2.41 degrees per hour meaning that it would kick on once about every 2 hours or so. Thats not too bad.

My girlfriend works at Honeywell. She is going to ask the facilities HVAC staff if I need to be concerned or not.

 

[basilchef]

Well, here is the thing. I have been googling to find out if there is anyone who can speak to this, but I can't seem to find any evidence or a site claiming that using a traditional power cut of is harmful or not. Normally I can find a good response on this site.

My thinking is this, the compressor runs at 1 speed. On and off. If it is cut off by means of just cutting the power to it, I cannot seem to fathom that it would do any damage to the compressor. Especially if I set it for a 5 degree variant , so its not kicking on so much.

Last night I turned the fridge off on its built in temp controller and it went from 46 to 75 in about 12 hours. SO figuring it only probably takes it a few minutes to cool to 65, I would set it on 65 and have it kick on at 70.That is 2.41 degrees per hour meaning that it would kick on once about every 2 hours or so. Thats not too bad.

My girlfriend works at Honeywell. She is going to ask the facilities HVAC staff if I need to be concerned or not.

Awesome let me know what she says. Im intrigued.

 

[wulfsburg]

So this is what I send my GF to ask her facilities/HVAC staff:

"The fridge only gets as warm as 50 degrees when regulated by the built in controls. It will then will cycle the compressor until it is back down to 45 degrees.
I need to maintain the fridge between 65 and 70 degrees a few times a year. I have a temperature controller that I can use with the fridge to cut all of the power to the fridge once it gets to a certain temperature. The temp controller is set for a 5 degree variant.


I need to maintain the temperature of the fridge at 65 degrees. So when it hits 70 degrees, it will restore power to the fridge until a temp of 65 degrees is attained. Because this device is regulating temperature by cutting ALL power to the fridge (rather than just the compressor circuit).
My question is, is cutting all power to the fridge with an external control going to harm the fridge or cause it to pre maturely wear out? The fridge gains 2.4 degrees every 2 hours, so I imagine it will kick on for a few minutes a day 10-12 days depending on ambient temperature. This will only be done a few times of the year and for an average of 9 days in each cycle."


His response:

"I don’t see any problems with that,
We usually make up a 6x6 inch box with a male115 volt plug and female plug to plug in the appliance.
You can put a 115Volt relay inside the box to make and break the hot leg of the 115v source,

You also may want to use a temp controller."






So, due to lack of evidence online and the confirmation of another person who works with these kinds of things, I would say it is safe to use it for a fermentation chamber.

 

[basilchef]

thanks for the update.

 

[day_trippr]

fwiw, a $500 fridge these days is plain vanilla.

I've been running two beer fridges and a keezer for a couple of years now. One fridge is set for constant 36°F, one fridge does fermentation duty typically in the low 60°F range and is controlled by a Ranco single-stage digital unit. The keezer runs at 34° +1 and also is controlled by the same model unit. From all appearances (and my electric bill) they all seem very happy with their lot.

If you avoid doing stupid things like taping temperature probes to cooled side walls or dunking in glasses of water and instead monitor either the interior fluid temperature (thermowell) or at least the vessel exterior temperature (with some insulation outside of the probe interface) you can run very tight dead-bands (like 1 °F) without short-cycling the compressor...

Cheers!