ffire5 said:
Bummer. I got excited about my new fridge and didn't compare these close enough. Thanks for pointing out the 5 amp limitation. You might have saved me from a house fire. Now I just have salvage a relay or head over to radio shack because I was too lazy to convert to C.
Any reason why a heater is essential in a fermentor? Will the temp drop all that much once the switch turns off the fridge? I would imagine the cooling alone keeps it within 3-5 degrees and both keep it within 1?
Am I incorrect thinking a 5 wire relay will work the same as the dual controllers? When the cold is off the heat is on... or does the stc have a neutral zone?
Thanks in advance!
Yes, temperature controllers have a neutral zone. The size of it is set by the user, but there's always a minimum. People don't really go lower than 1° even when they can, and some people even go several degrees higher (which is unnecessary if you set up the temp probe correctly). Otherwise, you'd be straddling the boundary of your setpoint, quickly shifting from cool to heat to cool again. Not only does this significantly reduce efficiency, but it will wear out the compressor on your fridge really quickly. That unit might force some sort of delay to protect the compressor, and you could use THAT to create a sort of neutral zone, but even the maximum settings on these controllers will have it cycling at least several times more often. Basically, the drastically shortened lifetime of the fridge and possibly even just the reduced efficiency from always having something on is going to end up costing you a lot more than just buying a proper dual-stage.
Which brings me to the part of whether or not dual-stage necessary. It depends, but circumstances that make it good to have are very common. Unless the ambient temperature where you keep your fridge is ALWAYS higher than any you could ever possibly want to ferment at, then yeah... you'll want it. If you make Belgian abbey ales or saisons, then there's no question about it. And merely switching it to heating for those beers above ambient isn't really a good idea, even if that ambient temperature is extremely stable (eg, in the room where your thermostat is). Because an active fermentation often raises the temperature of the beer between 5 and 10 degrees, there are going to be beers that require cooling when the yeast is at peak activity, and heating at periods of low activity, in order to keep the temperature of the beer consistent.
How many beers will you be able to ferment at once, anyways? If it's more than one, then there's no question that you should just buy an STC-1000 as well. The reason is that it'd allow you to ferment beers at different temperatures. For example, if you're fermenting two beers, you would put the STC-1000 on the beer that ferments at the cooler temperature, and the one you have right now on the one that ferments at the higher temperature. That way, if ANY of the beers are too warm, the cooling can turn on. If it's too cool for both beers, then they both turn the heat on. And if only the warmer-fermenting beer is too cool, it can simply heat itself up - although this kind of specificity requires a fermwrap, or some other sort of heat source directly contacting the fermentor (and preferably insulated from the air around it.) As you might have figured out already, it's best to have a controller for each fermentor, though only one of them needs to be dual-stage. And the rest of the temp controllers only need to control heating, which rarely requires even 1 amp, let alone 5 (a Fermwrap is 0.33A), so the one you have would still be useful, and if you needed more, you could buy whichever one you want.
But if you can only fit one fermentor in there, the choice is not so clear cut for some people. Like I said, using a relay (and as a result, having no real buffer zone) will end up costing you more in the end, and these things are so inexpensive, that I would just buy an STC-1000 anyways. Heck, the relay itself would cost you about half of what the temp controller itself costs (especially since NC relays aren't as cheap as NO relays), and you could probably make up the balance, or even a bit more, by selling the controller you have (though you will probably find a use for it down the road), so doing things the right way might even be cheaper up-front, let alone in the long run.
