Ferm Chamber Design Critique

[JayInJersey]

Before I invest any additional time into this project, I wanted to hear whether you all think it is feasible.


Basically I have a 10' x 4' x 4' alcove in my garage that I was want to turn into my storage area/ferm chamber.

I use exclusively now the 8G Vittles Vaults (roughly 14" squares) so I'm figuring 2'sq would be plenty of space around them for ease of movement and stuff like that.

Each chamber is independently controlled by a Love controller that would activate/deactivate the fans to pull down air from the chamber above.

The top most chamber is cooled using a 6000 BTU Windows A/C unit (there will be a tray under it and that empties down a pipe on the side for condensation).

Each chamber is roughly 24sq.ft. (Sq Ft is LxWxH right?...or is that volume DAMN geometry!)

I figure the hardest part will be to stabilize each compartment...but then it should maintain fine.

I also haven't decided if two fans would be necessary for each chamber or one...but you get the idea.

Thoughts? Concerns? Comments?

 

[Layne]

Keep in mind, heat rises. It may be easier to cool from the bottom up. But thats just a guess.

 

[Boerderij_Kabouter]

Cold air sinks, you have the design upside down. Other than that I am interested to see how this works.

 

[JayInJersey]

Granted. Heat rises and cold air sinks...but isn't the warmest part of a refrigerator the produce drawer at the bottom?
I know my little dorm fridge that has no coolant lines just a frozen "freezer" tray it will be 30 at that tray but 45 at the very bottom.


When I Sketched this up I just thought about the old "Ice Boxes" ... the ones that actually were powered by a big ice block at the top.

I figure that as the air falls further from the cold generation point (the A/C unit) it would warm up, no?


Not saying I'm right...just trying to think this through.

 

[Layne]

Hmmm interesting thought.
I guess the question is how to control it. How to keep certain levels at certain temps.
Very interesting idea. The same footprint of one small fermenter, but no wasted space above.

 

[JayInJersey]

I think I might have to make a small balsa wood proof in concept...I knew keeping all that model building junk would come in handy one day. (Damn I now wish I knew where all my legos went as this would be a perfect use for them)


Now to think of a cheap small scale insulator for the PiC model...newspaper maybe?
Figure an ice cube should work for an A/C stand-in.

 

[JayInJersey]

So I tossed out the balsa wood PiC idea as I can't find cheap miniature fans for the levels...I think the cheapest way to pull this off might be to build a non-controlled / non-insulated one and just run it to see what happens. After all I always have 2x4s around and can find a cheapo A/C unit.

But I did take some temp readings of my Top Freezer fridge.
And I'm thoroughly confused...

The Produce drawer turned out to be the warmest (I didn't measure the door), but the shelf right above it...the coldest. Then slowly warmer as it goes up.

 

[Boerderij_Kabouter]

Fridges work by moving cold air from the freezer side into the fridge side. The bottom drawer is usually warmer because it is completely shut off from the freezer and from the fridge main air chamber. Typically the only air access to the vegi drawer on the bottom is a very small vent you can move (usually from Vegi →fruit or similar settings). I think they put it down there because the cold air comes in at the top and they want good air flow to all other parts of the fridge side.

Cold air sinks. It is physics. In your design, the bottom chamber will fill with cold air and the fans will be working against gravity.

Another way you could do it, would be to isolate each level, then run conduits from a cold air box at the bottom to each isolated box. No communication between the boxes so temps would be less dependent. More HVAC routing though that way...

 

[JayInJersey]

Wait I think I see where I'm getting everyone confused.

In the original mock-up those "square holes" are suppose to have fans in them (either one or two depending not sure what would be needed). I was considering cheapo "bath fans".

And that would be the ONLY open hole between levels.

Granted even while the fan was "off" some cooler air would sink to the lower level...but I'm not really sure how much would "seep" down there so I can't say how much it would cool that compartment. But when/if the compartment got too hot it would kick on that fan and pull some cool air down.

No?