Brew Fridge - What type of heater

[Bigcol49]

Oh Dear! More things to worry about!
My tubular heater sits below the FV, and I don't use a fan. The heat will rise anyway. Also, the heater is not on all of the time, so that gives the "heat" in the liquid time to equalise by conduction/convection (physicists - put me right). I don't worry about the bottom of the FV being closer to the radiant heat. I doubt whether there'll be more than a degree difference between the top and bottom (in my case).
I think that there are two types of home brewers out there - the control freaks who worry about every fine detail, and if there's nothing to worry about, they'll make something up, and those who, like me, follow the received wisdom, bung a brew in, stop worrying and sup the result (which is usually excellent, or at the very least, drinkable).
Right, I'm ready for the critics!

 

[Leon103]

Surely it doesn't make that much difference in such a small air space

 

[Twostage]

Yep, a good idea with convected heat but no amount of air flow will dissipate radiant heat. You cant blow light with a fan, which is all UV is, just different wavelengths.

Or even IR. UV is cold, IR is hot.

My brew fridge has two fans . One at the bottom where the lamps are and one in the freezer box at the top (with the door removed). It is important to circulate the heat/cold around the fridge so that the STC (or other ) sensor can react to the changes in temperature.

I suppose there is a risk that having the heat source close to the FV can induce localised heating but with an STC with a .3 degree setting the air will heat rapidly and switch the heat source off before it is significant. Just think how log it takes a boiler to heat your mash water when it is in direct contact with a 2.5kw heating element.

 

[Mickeywheelspin]

Or even IR. UV is cold, IR is hot.

Indeed - Must stop trying to multitask the basic point stands though

Just think how log it takes a boiler to heat your mash water when it is in direct contact with a 2.5kw heating element.

Yes, but equally, isnt your element covered in scorched wort after close contact during the boil? The whole boil takes an age to warm up but the element still gets hot. Ok, so we're not dropping greenhouse heaters in the FV to have direct contact with the wort but given how sensitive some yeasts are to temperature, which has a bearing on flavour, it seems like a reasonable idea to diffuse the direct heat.

With your setup fan(s) make sense to circulate the air. With mine it just seemed like a good idea to stuff a spare bit of packing material between the element and FV. Each to their own. Part of what makes this hobby so satisfying is the ability to customise your setup and refine your own processes. :thumb:

Just my musings but makes sense to me so I'll crack on with what works for me

 

[Twostage]

Just my musings but makes sense to me so I'll crack on with what works for me

And that is the most important part in all of this.

If it works it can't be wrong :-)

 

[Favershambrewer]

So to answer the OP. I bought a 25w aquarium heater and an Inkbird 308. Notwithstanding the fact that my 'new' fridge went bang three minutes after it went on (not a fault of the inkbird; the fridge had been unused for a while) I've been finding the heater ok.

The stuff I have to work out is where best to position the probe and what point the heat or cool cuts in, as I don't want continuous cycling.

 

[Hoddy]

So just get two in one. I use a hair drier on the lowest setting connected to and stc-1000. When the temps too cold the hair drier kicks in, when it's too hot the fridge comes on. Perfect temp control within 0.5 degress for anything you like. Voila!!!

 

[clarkeuk]

I got a 1ft one of these works great.

http://www.ebay.co.uk/itm/141557998704?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Iv one of these too in my beer fridge and it works fine

 

[Bigcol49]

Favershambrewer - somewhere online is a detailed and very scientific post about positioning of the sensor for the best temperature control, and the conclusion was to hold the sensor on the exterior of the FV covered by bubble wrap or similar insulation.

 

[Twostage]

Favershambrewer - somewhere online is a detailed and very scientific post about positioning of the sensor for the best temperature control, and the conclusion was to hold the sensor on the exterior of the FV covered by bubble wrap or similar insulation.

I'd like to see that post as it conflicts with my experience. See post 18 on here :-

http://www.thehomebrewforum.co.uk/showthread.php?t=54503&page=2

 

[Bigcol49]

Hi, Twostage,
Here is the post - it's from "another place": http://www.jimsbeerkit.co.uk/forum/viewtopic.php?f=6&t=68518
To be totally fair, I don't think it covers a probe in the airspace of the fridge, but it still makes interesting reading.
His conclusion about switching the fridge off must apply to British winters - I don't think my brew fridge has switched on at all during my current brew.
Colin

 

[Leon103]

Heater and itc 308 ordered. The 308 is now only £26.99 brilliant.

 

[Simonh82]

I picked up an ITC-308 and it is great. My entire brew fridge build took about three hours and that included bodging up a wooden shelf/stool thing for the FV to sit on.

I took twostage's advice and went for the temp probe recording the ambient temperature rather than stuck to the fermentation vessel. It seems to work really well.

A PC fan definitely makes a difference to the temperature readings if you are recorded ambient temperature. My bad wiring on the fan disconnected itself just as I started cold crashing. I couldn't get the fridge down to past 4.5 oC until I spotted the wire had disconnected. When I reconnected it the fridge temp reading dropped from 6oC to 2oC.

 

[Leon103]

So what's the best way to wire a pic fan? Idiots guide please

 

[Twostage]

Hi, Twostage,
Here is the post - it's from "another place": http://www.jimsbeerkit.co.uk/forum/viewtopic.php?f=6&t=68518
To be totally fair, I don't think it covers a probe in the airspace of the fridge, but it still makes interesting reading.
His conclusion about switching the fridge off must apply to British winters - I don't think my brew fridge has switched on at all during my current brew.
Colin

Hmmmm.

Read it a couple of times and been forced to come to the conclusion that he's made a mistake somewhere. Wonder if he got confused with doing so many experiments. Some look right, some not. If you look at experiment 4 where he is using a probe on the FV to control the heat cool cycle, the temperature of the brew is obviously not controlling it. If it was the brew's temperature would vary by the sensitivity of the STC (+/- .3 degrees). In other words it would vary by between .3 and .6 degrees overall, according to his graphs it is the fridge that is varying by that so the controlling probe must be monitoring the air space. He should have spotted that as one of the data panels gives that max and min beer temps as 20.06 and 19.88, a difference of .18. It is not possible for it to be less than .3 if he is controlling by beer temp. Haven't read the replies to the thread. Does anyone else pick this up ?

 

[Twostage]

So what's the best way to wire a pic fan? Idiots guide please

Chop the end off a phone charger and wire it to the fan.

Better still is a variable voltage power supply so you can tune the speed of the fan. Think I got mine for a fiver from flea bay.

By the way the PC fan needs to have red and black cables, not the green yellow ones as they require a stepper motor controller.

I can post pics if you want but it is that easy. (I could also post you a fan as I have two spare).

 

[ManseMasher]

So what's the best way to wire a pic fan? Idiots guide please

My pc fans both have 3 wires - positive, neutral and signal. All 3 are black (one has white dashes on it). I chopped the end of my power supply of (an old broadband router one), stripped the wires and pushed them in the fan cable socket. When I put them against the correct pins, fan started spinning. I then chopped off the fan connector, joined the two power wires together, job done.

 

[Leon103]

Chop the end off a phone charger and wire it to the fan.

Better still is a variable voltage power supply so you can tune the speed of the fan. Think I got mine for a fiver from flea bay.

By the way the PC fan needs to have red and black cables, not the green yellow ones as they require a stepper motor controller.

I can post pics if you want but it is that easy. (I could also post you a fan as I have two spare).

If you have one spare that would be great. Have plenty of power cables I can use.

 

[Twostage]

If you have one spare that would be great. Have plenty of power cables I can use.

PM me with your address and I'll stick one in the post.

 

[Leon103]

Today is the day I start the fridge build. Just need to clear the garage so it's in the correct position etc. May need a little help with the fan. Unfortunately I can put all my cables through the drip hole so going to be drilling a hole in the fridge. Was think either the door or the side panel near the door. Put all cables in places then use some sealant to seal it back up