As readers know, the office-shop of UrbanSurvival is a glorious (verging on palatial) place:  Tools galore, plenty of electronics for the Extra Class ham radio op in you, or whatever turns your crank.  Pass the plasma cutter and sample three different “on-ramps” to the Internet.

With summer here, though, and not figuring it to be worth the expense of fully-insulating the shop (mostly 2-4 studs covered with clear polycarbonate panels to let in lots of natural light), I went looking for solutions that would fit within the “energy budget” of our solar power system.  Which, if you’ve forgotten is 400 Amp-hours of battery and 110/220 volt stacked Outback Power grid-interactive inverters driven by 3.5 kW of panels and a pair of Flex-60 MPTP charge controllers.

I came up with basically five ways to cool the shop.  Some practical, some not so much.  First would be to run A/C and go with a somewhat more efficient inverter-DC unit.  In old-style air conditioners, the compressor is cycled on and off for cooling.  But, with the new technology, the compressor, fans, and the whole shooting match runs continuously…just not as fast.  Avoiding the high-current stop-start, turns out, saves a lot of energy.  But, like any new tech, it’s more money…

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A second option would be a “swamp cooler” – not to be confused with rain in the nation’s capitol.

The way these work is water is drizzled water over a “media” (think gunny sacks) pumped by a small aquarium pump while and a big herking fan blows air through it.  Cooling is the result of the evaporating water soaking up heat.

It all sounds good because it can generate cooling at a fraction of the cost of conventional (compressor AC).  It only works, though, with relative humidity under 60%.  A bone-dry desert is better, though.

I had only been in one place in recent years in the summer, where this kind of cooling was used.  That was a hardware store in Frankston, Texas.

So, I called them up to see how well their unit worked.  Always check with people who have first-hand experience, right? Around here, the humidity levels are all over the place.  With the peak heat of the day, they may drop to 40 percent.  But in the mornings, when it’s gotten down to 70 overnight and there is heavy dew, you may see 100 percent.

Not in a shop,” someone answering the phone began.  We had a nice chat about how the cool, but very moist air, works for some thing, but how tools doesn’t last long.  Things rust…quickly. Blink quick.

Then I penciled out a couple of “exotic solutions.”  One – which works well, I hear, is to bury as much 12 to 20 inch diameter plastic pipe as you can afford down 10-feet, or deeper.  Average ground temps run in the mid 60’s here, so simple and cheap!

You put an intake pipe up several feet in the air (keeps critters out) at the far end, perhaps 150 feet of pipe away, filtering filters (another use for women’s nylons, last seen in 2003).  Then power the whole shebang with a 12 or 24 volt DC fan to suck cool air into the building..

Since we have an old HydraJet water well rig, I could do the same thing by building-up long 4-inch copper tubing coils and dropping two or three of them down to the ground water level, which is about 70 feet under the office depending on time of year.

At the other end, a small repurposed car radiator and a 24 volt water pump would circulate the water from the heat sink underground to the radiator in the office with an air fan on the office side.  Scaled up to the size of the shop, though, this begins to look like a plumber’s wet dream and a PVC pipe rep’s retirement package. Nice dream for a radiator shop,. too.

Then we come to thermal cooling towers, one of the first low energy technologies, which comes by way of certain African villages where they form cool community living spaces.

The idea of a thermal cooling tower is you build an upside down  (flared end of a trumpet down) looking shelter out of reeds and wood.  As the sun heat the tower, up goes the air which naturally rises when warm.  This, creates a vacuum which pulls cool replacement air in around the base.

On a 90+ day, 5-10 miles an hour of updraft is dandy!

Sadly, there’s no way to accomplish this one, since there are too many tall pines around the office.  It would take 20-40 trees being removed and that’s not economic.

Understand that as a tree farm operator, there are only two ways to approach trees:  Either hire specialists (the last one charged $800 to cut down one tree) or get enough trees lined up that a local logging outfit could bring in a crew and equipment for a week and move out lots of trees.  In the latter cas,, you make a fair bit on the tree sale, but the land is left a mess.

Way too much hassle just to make the shop a little more comfortable.

So…;the winner is?

Pardon the long link here: Portable Dehumidifier by hOmeLabs, 9 Gallon (70 Pint) Energy Star Safe Mid Size for Basements Large Rooms up to 4000 Sq Ft with Fan Wheels and Drain Hose Outlet to Remove Odor and Allergens…

Don’t buy the unit, just yet.

The Amazon/manufacturer specs are misleading.

Let me tell you a story of how “Marketing People are Idiots” and show you how the specs are wrong on the unit I received…

It arrived Tuesday, courtesy of the USPS.  I left a hand truck out for our Post Office carrier (Jason) so he could just plop it out of his ride’s trunk and onto the hand truck, so as not to break a sweat.  By the time it was unwrapped and set up (there’s a plastic part in the water tank, so don’t forget to remove it…like someone I know didn’t!) it was 4 PM.

I figured it would run it overnight and might suck a gallon of water out.

Imagine my shock when, at 5 AM the next day, I came out to the shop and found it was full, already.

Could it pull 9 gallons in less than 12 hours?

After dumping the water, an alarm bell went off:  The Amazon write-updid say this was a 70-pint capacity unit.

It’s not.  Er…it is, but depending on how you define capacity.

Remember the old saying “Pint’s a pound the World-around?”  8 pounds per gallon?

Well, sleepy though I was, the weight of the water taken out of the unit was far less than 72 pounds if 9 of those 8 pound gallons were captured.. It felt like 10-15 pounds.  I’m buff for 69, but are you kidding me?

After waiting for the unit to suck another load of water out of the shop air, I waited for it to turn off when full.

Since I’d started the unit at 5 AM, and sure enough, around 10:15 AM, it was full for a second time.

Since my shop is called Olde Man Labs where I work on real physics questions (see my books on Amazon), here’s my set up for testing:

I weighed the full water tank.  Here’s what the digital number-twanger reported:

Oh-oh.  14-pounds 10-ounces?  The very tops it could be holding would be (14+(10/16) would be 14.625 pints. or 1.828125 gallons.

But it’s not really even that much.  We still have to back-out the weight of the empty water bin in the unit.

I didn’t thoroughly dry it, but it weighs how much?

So we take the total (14.625 pounds) of water plus the water bin.  Then we back out 2.85 pounds (which is the water bin weight empty (but not dried) and we get a REAL water capacity of 11.775 pounds.


There are other ways to estimate the tank’s real size.  Measure it.  Length times height times width.

Now divide:

And how many cubic inches are there is ONE gallon of water?


Say your measurements multiply to 500

500 divided by 231 means a 2.16 gallon capacity based on volume.

With both a weight and volume check, the capacity specs claimed in the add are useless.

That said, now you can go ahead and buy the unit.  We give it an initial four stars.

It sucks a LOT of water out of the air.  But will it work on 4,000 square feet of home?  Let’s just say when  one specification is obviously wrong, the other ones ought to be questioned.

What may have happened is the “70-pint capacity” could be based on how much water it MIGHT suck out of the air in a 24-hour period under ideal lab conditions. Even here, color me skeptical.  BUT it is pulling close to 4-gallons out of the Old Man Labs shop….and that’s why it’s OK to buy.

I doubt any of the dehumidifiers on the market will pass a real performance and measurement test like this.  Get the hose. Unless you like to water your lawn with a bucket.

Now to the prepping reason TO BUY the unit..


There really is an important prepping aspect to it which we do think about at  Lots..

I have not tested the water quality coming off the unit, but if I lived in another hot, humid state, like Florida, it would be simple to put together a good emergency water source using the unit.

Background:  When we were offshore sailing in the early 2000’s, we figured on a tight water ration, people on the boat could get by with one gallon per day, per person.  Two gallons would be generous.

If the unit puts out, four gallons per day, then two people might remain hydrated on its output.

I’d wash the bin to remove parting compound from manufacturing.  Run it through a LifeStraw or a lightweight reverse osmosis system, and now you have a dandy back-up water source, as long as you have power.  Minimal for four, workable for two.

I won’t be sending my unit back…it’s a keeper, at least so far.  But somewhere, back in marketing pre-history, a zealous marketer used the “70 pint” nomenclature and it seems to have gone viral.

Don’t buy the unit based on the specs…there’s simply not room for 70 pints.  Try 11.78 pints.

Don’t buy this unit for the specs.  Buy it for what it really does.

For us, for now, it’s OK.  We’d like to see Amazon do some “spec checking” though.

Write when you get rich,

Ther Problem with the CPI Data...
If Trillions Were Thousands