Post by baloononPost by JoergPost by JoergPost by Tom BiasiPost by JoergOn Monday I bought a Vinotemp VT182 "Wine Cellar" wine fridge. It
is a bit dinged up but it used to be a high-class affair. After
removing a lot of stuff in there and building two sturdy shelves it
should be able to hold two 6.5-gal primary fermenter buckets and
two 5-gal secondary plastic carboys (water cooler bottles). This
would allow me to keep on brewing full tilt during hot summers.
Yeehaw!
http://images.hayneedle.com/mgen/imagebywidth.ms?
img=master:VNT027.jpg&w=500&minh=300&maxh=500
Post by Tom BiasiPost by JoergThe electronic controller is fritzed in that it won't reliably
start up the compressor. I am sure I can fix that somehow. However
...
The temp range adjustment is 48F-65F. 65F seems low and I had my
"rigged" old Bosch fridge running at 67F-68F last summer. Midwest
usually suggests 65F as a minimum for their recipe kits while
Fermentis lists much lower minimums for the yeast that is used with
those kits (like BE-256 and US-05). The fridge has another flaw in
that by design the controller contains no non-volatile memory and
it will default to 55F after even a brief power outage. Not sure if
that could ruin my beers if I don't catch it for a few days.
What do thee say? Try to repair the old controller or hack it and
build something that can go higher in temperature?
Of course, for next winter I'll also build a load resistor box that
I can drop in there as a heater. Though that will be driven
externally with a separate regulator and safely run with low
voltage. This would save us pellet fuel because right now I am
often heating that basement room just so the fermenters are happy.
If the fermenters are well insulated they shouldn't need a lot of
extra heat. You could easily put an active fermenter next to a
fermenter or other big container filled with warm water and then wrap
them with sleeping blankets or a hot water heater blanket and that
ought to do pretty well unless the basement is really cold.
That is the kind of kludge I want to avoid because the downstairs
isn't a bland basement but a real room of the house. And I am married
:-)
Wait, the fermenters are in a regular room? Maybe covering the
insulation with a nice quilt would do the job then....
Downstairs we only heat via pellet stove if needed. So in the winter
that room often drops to 58F or less. The only reason I am keeping it
above 62F right now are the four fermenters. Mostly for the two primary
ones.
Post by baloononAt any rate, it sounds like the wine fridge is a much classier option
than a fiberglass covering.
It looks very posh but less so now that the wooden racks and metal rails
in the lower half are removed. Today I'll have to build and install a
sturdy mid-shelf and beef up the bottom because they will have to safely
hold 80 lbs each without much flexing. It'll have smooth formica topping
to that I can slide heavy buckets and bottles in and out easier and most
of all without lifting while having my arms streched out (my lower back
is not so great). If still too hard I'll build little "trucks",
microscopic furniture dollies or just wood plates with piano casters
underneath.
The fridge will go into a utility room downstairs so its looks are less
important. I did try yesterday and it can really hold two 6-1/2 gallon
fermenter buckets in the top after removing the rails. Two 5-gal water
cooler bottles in the bottom are easy, they even fit with the rails left
it (they were hard to remove).
Post by baloononPost by JoergPost by JoergPost by Tom BiasiMy vote is to get a new controller like a Ranco.
I think that's right, although if power outages are the only concern,
it's also possible to get a power brick like PCs have that ought to
keep power stable during a brief blip in supply.
Bricks won't drive a fridge compressor, they are most likely to stall
out on start. I could make a little battery backup just for the
controller but then I might as well build a new and better one. I was
just wondering if 65F is high enough.
I know I've seen them on lab fridges, maybe they're a lot more expensive
than typical ones.
Oh yeah, the ones for high surge current are expensive.
Post by baloononAt any rate, 48-65F is fine for most yeasts except a number of Belgians,
and for those you'd want a heater during the winter. Interior temps of
active fermenters are often a few degrees higher than external temps, so
the temp may actually be 66-68F at max, which is generally also fine.
What I am planning to do after all the mechanical mods are complete is
build a temp sense and compressor control circuit where I can detach the
sensor and strap it to the fermenter that has the most recent load in
it. This should avoid exceeding safe limits where the thing could go
nuclear or develop fusel oils.
Moving the fridge downstairs will be a white-knuckle job. Difficult. I
have removed everything that can be removed in order to reduce weight.
It's either down a very narrow stair case or all around the house and
half way down a very steep driveway with a 90 degree turn at the gate.
Post by baloononPost by JoergPost by JoergBut I think the big risk of going with the onboard controller instead
of getting a new one is that the existing one isn't accurate -- maybe
the thermometer is in a bad place or something else makes the whole
thing run cool or warm, and you'd be better off with something you
have more control over. One you could monitor and control wirelessly
would be especially nice.
The temperature sensing seem accurate and I checked the two sensors
for proper positioning. It measures in the upper and lower section.
What is not so good is the code in the micro controller that does the
regulation.
Depending on insulation, there might be a notable difference between the
far interior and the area by the door, which can be a bug or a feature
depending on how it works out.
Currently it has the sensors in back. The door is a very heavy dual-pane
deal like you see on upright supermarket freezers. I had a hard time
lifting it while carrying it downstairs.
The mid-section which contains the exisitng controller blocks air flow a
lot because it is like a complete shelf. It has 1" thick styrofoam
inside. The internal heat exchanger in the lower half seems to have a
lot more freon channels than the one in the upper half. While there are
no two different regulating circuits they say in the manual that the
lower half is colder for white wine storage. Red wine goes in the upper
half. Well, not anymore. I plan to put the primary fermenters in the
upper half and the secondary ones in the lower so that the secondary is
a bit cooler. Should also help whenever I want to do cold-crashing.
Post by baloononPost by JoergI want to keep it simple so it'll be an analog circuit. Some day I
might add a temp monitor that sends into the WiFi or wired LAN.
However, so far the "Internet of Things" is largely hype just like
home automation was for decades.
I've read you can do some interesting stuff with a Raspberry Pi,
although that is more tinkering than I want to think about for the
immediate present.
A Raspberry Pi would be overkill here. What I'll do first on a rainy day
is hack the existing controller so that I can pipe out the 5V supply,
ground and a switchable splice in the compressor control line. Then I'll
place a switch "Internal-External" and a large phono jack or something.
That allows me to turn the compressor off for times when I want to heat
and to plug in my own circuitry.
Then I'll build my own little electronics and mount that to the right
wall in the upper half where the guides used to be, using the existing
screw locations. With the option to connect a wire with sensor to that.
If I really get carried away maybe I cram a micro controller in there
for a real PID algorithm for more precise and even temperature control.
It could also control a resistor bank for heating although I'll have to
somehow feed in power for that.
The redneck method for heating it would be to place a brick in front of
our wood stove, wrap it in an old towel in the evening and place it in
the top half of the wine fridge. I'll probably try that before getting
carried away making a heater box and all.
Post by baloonon... Unfortunately, wireless cooking thermometers tend
not to have the kind of battery life that would make them a good long
term option.
That's easy. I'll have 5V available so I'd regulate that down to 3V and
the trabnsmitter would be powered all the time. Same with the receiver
in the office and maybe another one somewhere else. The proble with
those is paltry range. This can be improved with a better antenna but
technically that would violate its FCC compliance certification.
--
Regards, Joerg
http://www.analogconsultants.com/
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