Air cooled condenser. I'll NEVER go back to water cooling!

[Brutal]

If you were careful with the slope, I think you could get at least 5' or 6' of fin cooled pipe in a box that would hold a standard 20" window fan. I continue to be intrigued by this idea...

or placed across the front of a swamp cooler..

[actech]

Been thinking about this, want to some out at the garage but no water. Kept thinking about a/c coils not sure why never thought baseboard heat. Like the box fan idea. Mounted to garage window. Might work Well too

[rad14701]

Two ideas for air cooling...

1.) Build a shotgun condenser but instead of implementing a water jacket just use a header and bottom tank...

2.) Use copper plumbing strapping with pre-drilled holes as fins with copper tube soldered together with a header and bottom tubes with holes drilled the same spacing as the strapping... I made something similar years ago when tinkering with space heater ideas...

[mason jar]

I think the concern that mason jar has is that in the parallel tubes all the steam will want to
flow through the center tube and you will loose the surface area of the outer tubes.

This was something I drew up real quick. Basically its just a manifold. The
angled lines could be steam diverter paths.

Right Bagasso, that's what I was trying to say. I have to confess that it's been about 25 years since my last
physics class so I don't remember much about fluid/gas flow dynamics but something in the back of my head
tells me that a multi-path design like that might have issues with getting equal flow through all of the pipes.
Maybe the "manifold" idea that KYChemist drew up would help. Anyway, I'm not trying to be critical of the idea,
and I certainly could be wrong about the potential issues. As I always say; build it and let us know how it works!
I love to see people try new ideas.

If you were careful with the slope, I think you could get at least 5' or 6' of
fin cooled pipe in a box that would hold a standard 20" window fan. I continue to be intrigued by this
idea...

Nice drawing Michigan That is what I was trying to describe a few posts back, but I didn't do a
very good job. A picture's worth a thousand words. I like the idea of a single vapor path and I think it would
work pretty well as log as the fan was moving enough air. That would definitely take up less horizontal counter
space than mine does.

...Like the box fan idea. Mounted to garage window

There's a good idea Won't heat up the shed/garage/kitchen that way.

[Bagasso]

you could get at least 5' or 6' of fin cooled pipe in a box that would hold a standard 20" window fan.

And the air volume for standard 20" fans is supposed to be between 2,000 and 3,000 CFM. OP nocked down 1.6K with 5' and 1,000cfm and felt that 2x was very possible, so, if things scale up, 5' and 2,500 might be able to knock down 8kw.

Tempting, but I really want a desktop version.

[RandyMarshCT]

Rad, your idea of making it a shotgun really has me thinking. Rather than using 2 drilled plates on the top and bottom to mount the tubes, several could be used (maybe 20 or so, thinner material) with smaller holes in them for airflow. Perhaps even some copper mesh in there, not enough to choke it, just added surface area. Or maybe make the air holes switch back and forth from each side to force the air across each section as it travels up the jacket, like Harley does with his big product condensers. The outside tube could easily be PVC, like Jed was saying.

Interesting thread, Mason Jar. Have you ever seen Riku's MK-I design in his book "Designing and Building Automatic Stills"? He designed a VM reflux column cooled completely with air. He uses two of these finned heating pipes in a big "V" on top of a reflux column for the reflux condenser.

[mason jar]

Interesting thread, Mason Jar. Have you ever seen Riku's MK-I design in his book "Designing
and Building Automatic Stills"? He designed a VM reflux column cooled completely with air. He uses two of these
finned heating pipes in a big "V" on top of a reflux column for the reflux condenser.

No, I haven't seen that book. I got all the info I needed for all my projects here so I
never bothered looking for books on the subject. Sounds interesting though, I might have to
find me a copy of that one.

[mason jar]

And the air volume for standard 20" fans....Tempting, but I really want a desktop version.

Bagasso, do you have an idea to make one smaller than the 20" square fan and still be able to knock down
enough vapor? I would like to see that one. I might have to tear mine apart and build the smaller version
if that worked

[Bagasso]

Bagasso, do you have an idea to make one smaller than the 20" square fan and still be able to knock down
enough vapor?

I'm looking at a 12" table top fan rated at 930 cfm (on high). What I'm thinking is that larger fins on a single 1 foot section might do the trick. What size are the fins you are working with?

Also, from what I can see in the pics you posted, there are about 4 fins per inch, is this about right?

[mason jar]

I'm looking at a 12" table top fan rated at 930 cfm (on high). What I'm thinking is that
larger fins on a single 1 foot section might do the trick. What size are the fins you are working with?
Also, from what I can see in the pics you posted, there are about 4 fins per inch, is this about right?

Yeah, mine has 240 fins over 55 inches of length, so that's about 4 fins per inch. Each fin is 3 inch x 3.25 inch
so the area of each fin (after subtracting the area of the 3/4" pipe) is about 14.8 square inches, counting both
sides of the fin. With 240 fins, that's about 3550 square inches of fin surface area.

If you were to keep about the same fin pitch on your 12 inch section of pipe, I think a fin size of about
6.25 inches square would get you about the same surface area as mine was (if I calculated everything correctly).
With roughly the same total surface area and airflow rate, it seems like you would be able to handle about
the same power as mine.

How are you planning on making your fins?

[Bagasso]

With roughly the same total surface area and airflow rate, it seems like you would be able to handle about
the same power as mine.

Thanks for the info. Like I said, my plans are for something in the airstill range 250-300 watts so I won't need all that knock down power. Even my current set-up only has a 1kw hotplate and, as you found out with the rating of your burners, a lot of that energy never finds its way into the wash.

How are you planning on making your fins?

Beer cans. Can find them lying in the street or enjoy making empties. The coating they have might make them less than ideal but, for me, this would really more about working with what I have.

[mason jar]

Well I finally got the time to make a run with my new condenser. It worked great and I'm really glad I
went with air cooled. It's so much less hassle than my old water cooled setup.
Here's the results:

[shadylane]

Looks good mason jar. You've done a fine job with the build.

[Hound Dog]

[coastershiner]

Great idea and great execution! I never would have thought of that, but water works great for me, so I never pondered another alternative. Well done man

[mason jar]

Didn't want to hijack another thread so I copied some questions about my condenser from that thread here.

skow69 wrote:
Way cool. I think air cooling may have gotten somewhat of a bad rap in the past. Just for clarity let me ask:
1 So the total power input is one household burner of natural gas, right?

The pot is so large that it can cover two of the burners. Each burner is supposedly rated at 9500 BTU (2.8 kW)
so I'm putting 5.6 kW into the boiler.

skow69 wrote:
2 Does the heat exchanger have any trouble handling that, or does it seem to have plenty of capacity for it?

Nope. Only about half of it is hot. The rest is nearly room temp.

skow69 wrote:
3 Is that a single tube, manifold, or loops?

One straight copper tube with a lot of aluminum fins.

skow69 wrote:
4 How many fans, and how are they arranged?

Nine 120mm, 120V AC fans rated at 100 cubic feet per minute

[skow69]

Thanks, m. j. I came over here and read the whole thread earlier. Your work makes air cooling look way more practical than the conventional wisdom holds. I'm sure you have seen swag's recent work also, which was successful despite using just a tiny fraction of the surface area you have. And there was another one with two vertical pipes in parallel and some seriously badassed computer fans. BTW I'm sure you're right that more than two pipes would be impossible to distribute the vapor. I, like you, would like to see you hang your condenser on a test rig of some sort and find it's limits. Surface area and air volume can't scale up evenly forever. It would be interesting to see where the point of diminishing returns lies.

I find this all very encouraging. It's obvious that a clean water supply is going to be a problem for more people worldwide every year. Southern Cal is just a little ahead of the curve.

So thank you for your good work. A lot of people hereabouts seem to be caught in the age old trap of thinking that everything that's worthwhile to invent already has been. I suspect that in 10 or 20 years we'll look back at what we're doing now and laugh at how silly we were. Kudos.

[francis]

I like air cooling too. We are on a well so I would like to avoid water cooling, pumps etc..

PC fans are cheap, and they are brushless - so no spark. They also move a lot of air, and you can put them in pushing and pulling configurations.

Baseboard heating pipes with fins: Riku uses this too in this ARC book. But I see a problem with it. The fins are parallel to each other.

There are two ways heat is dissipated, by convection and by radiation.

Since the fins are parallel to each other they radiate heat into the adjacent fin. So most of the cooling ends up being by convection. Don't underestimate radiative cooling.

I experimented with unravelling then wrapping copper pot scrubbers around a worm and it cooled great. It greatly increased the radiative and conductive heat dissipation.

There is another way to air cool too - expansion. When a gas expands into a larger space it cools, since temperature is average kinetic energy.

[mason jar]

I like air cooling too. We are on a well so I would like to avoid water cooling, pumps etc..

Yeah, trying to save water was part of the reason I did this project since the area I live in has been
under a severe drought. You could see the bottom of one of our lakes (our main water source) in
several spots. Just recently we've had a huge amount of rain. The lake rose something like 40 feet
in one week . So the drought is over (for now), but I'm gonna stick with air-cooling since it's
much less hassle

PC fans are cheap, and they are brushless - so no spark.

Good point, I never thought about the potential for sparks.

They also move a lot of air, and you can put them in pushing and pulling configurations.
Baseboard heating pipes with fins: Riku uses this too in this ARC book. But I see a problem with it.
The fins are parallel to each other. There are two ways heat is dissipated, by convection and by radiation.
Since the fins are parallel to each other they radiate heat into the adjacent fin. So most of the cooling ends
up being by convection.

Don't underestimate radiative cooling. I experimented with unravelling then wrapping copper pot scrubbers
around a worm and it cooled great. It greatly increased the radiative and conductive heat dissipation.

How much power were you able to knock down with that setup?

[Bagasso]

How much power were you able to knock down with that setup?

Francis posted pics http://homedistiller.org/forum/viewtopi ... 0#p7322522 and said that he was running 300 watts.

[francis]

How much power were you able to knock down with that setup?

Today I was running 400W and the worm was cool to the touch by the third descending loop. I didn't measure temperature. The still head was very hot, I could only touch it quickly. The first loop worm loop was quite warm to the touch, the second one slightly warm, the third room temp.

Small copper column packed with SS scrubbers.

The pic isn't great. The copper scrubbers make it look like a Christmas ornament, but they work. Much better than I imagined.

And the column looks much nicer on the boiler . . .

[mason jar]

How much power were you able to knock down with that setup?

Today I was running 400W and the worm was cool to the touch by the third descending loop. I didn't measure temperature. The still head was very hot, I could only touch it quickly. The first loop worm loop was quite warm to the touch, the second one slightly warm, the third room temp.

Francis, that's pretty good that just the worm and scrubbers alone knock down 400W. You've got, what, 6 loops in your
worm and only a couple of them are warm? If you covered all of the loops with scrubbies maybe you could knock down
almost twice as much?? Add a simple box fan blowing over the whole thing and it gets even better. Amazing for such
a simple setup

[NastyNate]

Mason, first off, excellent build. As a man who has lived in his share of apartments I can tell that ease of use is key with limited counter space and just the fact of "life" happening around the hobby.

My question though is how did you hook up all the fans? As I understand them, the don't have a typical plug you see on a regular desktop fan, they have a small cord you plug into a computer circuit board, correct? I'm as handy as the next guy but I'm not an electrician by any means. If you've already posted this I apologize.

[mason jar]

Mason, first off, excellent build. As a man who has lived in his share of apartments I can tell that ease of use is key with limited counter space and just the fact of "life" happening around the hobby.

Yeah, it's super easy to set up my still now. I used to have to go get buckets of water, hook up my hoses and pump
and hope the damn thing didn't spring a leak and flood my kitchen . Now I just plop the pot on the stove, plop the
condenser on the counter, hook it up, paste everything to seal it and go. When I'm done I break it down and stick
it back in the closet. Easy

My question though is how did you hook up all the fans? As I understand them, the don't have a typical plug you see on a regular desktop fan, they have a small cord you plug into a computer circuit board, correct? I'm as handy as the next guy but I'm not an electrician by any means. If you've already posted this I apologize.

The fans I used are 120V AC fans so they just run on normal household current. No circuit boards needed. Each one has two
little metal terminals sticking out of the side. Theoretically you could simply connect the two terminals on each fan to it's
own power cord and plug each one into a wall outlet, if you had enough outlets (or a big power strip). Make sense?

What I did was use some wire to hook them all up in parallel and then soldered on an old extension cord I had laying around
to the end of the chain. The cord just plugs right into a normal wall outlet. Let me know if that doesn't make sense and I'll
try to post a diagram or pic of how they are hooked up.

[Angel_Kefka]

Can you tell if you end up with a gradual temp change along the length like a liebig or worm would have? I would think there would be unless the first fan chilled it enough to condense there, which doesn't seem likely. Either way experience beats theory so thought I'd ask.

[Hound Dog]

Can you tell if you end up with a gradual temp change along the length like a liebig or worm would have? I would think there would be unless the first fan chilled it enough to condense there, which doesn't seem likely. Either way experience beats theory so thought I'd ask.

Mason did a great job documenting this build for us all to learn from. In the second post of the thread he wrote......

Once the entire condenser was up to temperature (even the output end was way too
hot for me too touch) I turned on the fans. Within 10 seconds the steam went away
and water started to drip out. The water was hot at first, but there was no more
steam. Within 2 minutes, only about the top 12 inches of the condenser was too hot
to touch. The next few inches were warm and the rest was nearly down to room temperature
(my kitchen was about 73F at the time). The water coming out of the condenser was
nearly down to room temperature within 3 minutes and it stayed that way for the rest
of my water run.

[Angel_Kefka]

Now I feel like an idiot. Read that just a couple weeks ago and completely spaced it.

[shadylane]

Deleted due to security fuck up.
Will repost later, because this is a good idea

[Hound Dog]

Now I feel like an idiot. Read that just a couple weeks ago and completely spaced it.

I blame it on good ethanol when I do that!

[shadylane]

You can order Hyrdronic baseboard heating elements from lowes.
The only thing inside the baseboard heater is a shiny new 3/4" X 24" copper tube with aluminum fins.
They also come in longer lengths. Using MichiganCornhusker's idea. Five of these should fit perfectly in front of a box fan.

Lowes has free shipping