Getting Close To Finish: My Cabinet Humidor

[neoflex]

You definatly have some talent. I wish I had the time, skill and patience to build such a work of art. Nice job. Looking forward to the pics of the finished product!
Where are you mounting the flux capacitor? Sorry couldn't resist with all the technical jargon that I got lost reading.

[RGD]

Originally Posted by neoflex

. . .
Where are you mounting the flux capacitor? . . .

Behind the top drawer right next to the third stage reflex ionizier -


Thanks everyone for the kind words and PMs -



Ron

[kvm]

Looks great Ron! Very nice work.

[ky toker]

Damn! Once I get my work area clear I hope to start on my own, but I doubt it will begin looking like such a beauty as yours. Nice work.

[omowasu]

Originally Posted by RGD

Now you show up - just when I'm almost done -

The total scope of my "cooling" engineering rests soley on the mistakes of others. There are way to many varibles for me to figure out the BTU's - in addtion to having to find my old college school books from 30 years ago -

The popular Peltier device that everyone is using in general is rated at 50 Deg F (11C) with the unit operating on 12-13.6 Vdc @ 4.4 Amps. The units that I am using are rated at 43 Deg F (6c) at 12-13.6 Vdc @ 5.7-6.8 Amps. So in the world of Peltiers that's a good amount more. My total cubic feet is 13.5 minus the shelves, Oasis and drawers. As the cooling of the Peltiers are directly related to how fast you can remove heat from the hot side - I have two fans (don't have the CFM rating handy) directly fastened to the heatsinks. Keep in mind that I have simply reversed the polarity of the units rather that take them apart - so my hot side is in contact with a large alum block and then the heat sink. As I am concered with cooling and not heating - I wanted the cooling heatsink to cool quicker and a larger surface area - hence the reverse.
Ducting - it's an open air design. Heat side is located on the bottom of the cabinet with the fans directly attacked blowing into the fins as you can see on the pics. As heat rises the colder cooling air is of course closer to the floor. Between the heatsinks - we have 1/16" metal and 1 1/4" of plywoods. I'm looking at zero heat transfer I believe through the wall. In addition my room temps would not normally get over 77/78 degrees. Average I would say would be 74/75 maybe. These are higher however than I would like to keep my smokes at. Inside temps of the humidors/coolers tend to run 1 or 2 degrees above room temps.

Anyway - that's it for now I guess - if you can come up with a format for figuring up capacity of these units - I'd love to hear it.

Later,

Ron

Hey Ron, thanks for the info! As far as I am aware, the cooling capacity of the Peltier junctions can be calculated, but heat load would need to be determined first (e.g. ft3 volume and temp) and factored in with hot surface temperature and cold surface temperature with a coefficient for the dielectric surfaces of the Peltier (is it aluminum or copper, etc)...

But, since your ambient room temperature will max out at 77 or 78 degrees, Ill call the mathematics a pain in the a$$ and agree that you will not have any issues maintaining the temp of that stunning humidor.

That said, I have worked with Peltiers before on a hobby board, and here are a few things to factor in (I assume you have probably already done this, but if anyone else wants a Peltier cooled humidor, this will help):

> Peltier junctions are subject to condensation and related damage when in use. If a cooled element is stuck in a cabinet with 70% humidity, it will accrue condensation. This condensation, in excess, can drip down on cigars or damage wood. Since yours are mounted on the bottom in what appears to be a plastic resorvoir, you should be OK. The units should be "externally sealed" to prevent intrusion of condensate - this looks like a bead of silicone around the internal dielectric.

> Peltiers are not efficient at 100% power due to excessive heat crossing the dielectric to the cooling surface. Pelters run best at 30%-80% of rated power. The cool thing about this is that a microcontroller or resistance based "dimmer" style switch (rheostat) can be used to maintain a constant power level and temperature without exceeding specified parameters.

> The efficiency of a Peltier junction is directly related to how much heat can be removed from the heat sink. Adding forced convection via the biscuits and the low ambient room temperature are more than enough to compensate for any heat buildup under the unit.

I may attempt a Peltier-cooled humidor this winter. It will be a much smaller unit (maybe 200 sticks), but the rationale behind it is that my house hits 80 degrees in the summer, and 70% RH a 80 degrees is a far cry from 70%RH at 70 degrees!

[opus]

Beautiful work Ron. How are you going to handle the condensation? That was the biggest problem with my humidor project.http://www.clubstogie.com/vb/showthread.php?t=20784

[RGD]

Originally Posted by opusxox

Beautiful work Ron. How are you going to handle the condensation? That was the biggest problem with my humidor project.http://www.clubstogie.com/vb/showthread.php?t=20784

Yes- saw your unit - excellent job you did on it.

I have mounted my peltiers in a plastic tray that is fastened with a marine grade sealant/adhesive. I'm expecting the condensation to evaporate. If it proves to be more than expected and/or I have problems with the RH levels due to the condensation - then I'm fully prepared to install a "J" trapped drain line into a condensate tray that will simply lay under the cabinet - similar to any refrig except they don't use a "J" trap. I would construct this simply from 3/8" inch copper.

Anyway - that's the plan.

Ron

[opus]

Originally Posted by RGD

Yes- saw your unit - excellent job you did on it.

I have mounted my peltiers in a plastic tray that is fastened with a marine grade sealant/adhesive. I'm expecting the condensation to evaporate. If it proves to be more than expected and/or I have problems with the RH levels due to the condensation - then I'm fully prepared to install a "J" trapped drain line into a condensate tray that will simply lay under the cabinet - similar to any refrig except they don't use a "J" trap. I would construct this simply from 3/8" inch copper.

Anyway - that's the plan.

Ron

Sounds like a good plan to me. My unit produces about a 1 1/2 cups of conednsate per week. Mine drains into a condensate tray as well, although a different setup than a J trap. I think you should go ahead and install the J trap. I love the tidiness of your peltier setup and wiring. Excellent work.

[RGD]

Just a little update. The new, bigger power supply came in so I got that all hooked up. Went by the computer store to get another fan to install on it and they had some 120mm Stealth fans (verses the 92mm I was using) so I picked up two of those to go on the heat sinks for the hot side. More air = better cooling - Had to make some new brackets for the fans as they were to large to connect directly to the heatsinks. (Forgot the pictures)
Stealth fans are pricey - but very quiet!

So the pictures below:

Attached a lead from my meter to I can see what the actually surface temp of the cold side heatsinks are. Placed the remote sensor for the Radio Shack unit inside - it's working. Also place the Oasis II in there and filled up. As it does not have a digital read out - I will need to know how much to turn the dial.
Taped up some plywood/cardboard over the openings and we will let it run for a week and see what's up. I also turned up the A/C for the shop to 74 which is what the house is closer to. Actually the wife likes it at 75 - but hey, close enough.

Anyway - on with the testing -

Ron

[Guitarman-S.T-]

Very nice =]

[mr.c]

Makes me glad I have a basement

very nice work!

[Bob]

Ron, great job....wish I was as talented!

[cpkong]

Now thats a project!

[RPB67]

Beautiful pictures.

Coming along great.

[drawfour]

I know it's only been a week and a half since your last update, but give us another!!! (And looking nice, BTW )