Wet wall thread for MrB

Wow, well built but damn expensive.

 

I have a swamp cooler for my greenhouse. It only projects about 12-15" from the wall. I had real estate issues also, and this thing is a godsend.

 

What are the face dimensions? - Just trying to get an idea of surface area.

 

Nice! Thank you for posting the pics. That answered many questions. I still wonder....
What's the capacity of your reservoir and how long does it last? Do you just use tap water? I dread the certain hassles of possibly using my tap water. I'm imagining that within a month the pads would look like a cave formation due to the 350-500ppm 'water' in this city. But then maybe a vinegar rinse would just wash it away. You probably have perfect tap water. Any mineral buildup issues?

I'm thinking i could do wood for the framing and save big bucks. Maybe paint pressure-treated with marine epoxy or somesuch and it should last a long time.

Is your drip tube just a perforated pvc pipe? I was kinda thinking a length of soaker hose might work.

Here's a question for anyone that knows: What, if anything, is the advantage of an off the shelf swamp cooler vs. a DIY wet wall such as this? Or vice versa. TIA

 

MrB
I've lived with a wet pad cooling system for more than 12 years, and I would give serious consideration to swamp coolers if I were doing this over again. Cost-wise it's a matter of sizing both systems and running the numbers. Swamp coolers would eliminate the need for powered shutters; the positive pressure would operate gravity shutters. Outside of fan belts, the next items to fail for me have been shutter operators. I replaced my Kool Cel (sp?) pads at ten years; I could have saved the money. When I cut them open they looked fine-there was only cosmetic damage. I don't know know what media swamp coolers are using now, but ages ago when they used excelsior pads it had to be replaced more or less annually. As far as capacity of the reservoir, it serves two purposes: hold enough water to fully charge the system and start the return flow on start-up without running the pump dry, and to contain the water that drains out of the system when the pump shuts down. I'm not sure what type of soaker hose you're considering, but I suspect it would provide insufficient flow. I'm not a big record keeper for this kind of thing, so I don't remember if I've replaced the initial pump once or twice. Your weather is enough like mine that you'll probably find that the cooling will run 24/7 in the summer.

 

Mr B - Certainly marine or epoxy paint would look nicer, but I bought a homemade swamp cooler from someone when I lived in KY, and it was untreated lumber, painted on the inside with asphalt tar sold to waterproof foundations, and on the outside with a household oil-based paint.

No issue from rot for 8 years before I needed a bigger one and sold it.

 

Great thread -- lots of good information! I was thinking -- "hmmm, I could build one of those" -- at least until I got to the total cost. Not sure I am game for that.

 

I am toying with the idea of building a "swamp cooler in a barrel" as an experiment.

The manufacturer sent me a whole pallet of brick red "EcoWeb", and when I told them about the error (I have never seen a plant substrate that color), they asked me to dispose of it, rather than them paying to ship it back, and I'm such a packrat...

Anyway, the concept is a sump area at the bottom of a 55-gallon drum, containing a submersible pump that pumps up to spray head atop a stack of the polymer fiber pads. There will be a PVC pipe in the middle with a blower to pull air down through the wetted pads, then up the pipe and into the GH.

I'm pretty sure the evaporation off of the stack will be adequate; all I have to do is size the pipe and blower for sufficient air flow. Thoughts?

 

Just off the top of my head:
By limiting yourself to the diameter of the barrel, you have reduced the surface area of the media to 1/3 of the area of a swamp cooler of similar footprint. You might be able to make up for some of that loss by increased thickness, but not much. Most of the cooling is in the first couple of inches, and drops off as the air becomes saturated with moisture.
The free area of the EcoWeb may be limiting. I have'nt actually held the material, but when wet you may not be able to pull any air through it. The characteristics that make it a good growing medium my act against you.
My guess is that you won't be able to move enough air to be useful.

 

The webbing is VERY open - the polymer only accounts for about 3-4% of the bulk density - so it will hardly restrict the air flow at all. Don't forget that it is used in biowalls, in which the air is drawn through for purification by the mycorrhizal fungi that populate the plants' roots.

Unlike the media of typical swamp coolers, I don't think the polymer will be thoroughly saturated, and I'll be relying primarily on the surface area of multitudes of droplets, instead, so the real trick will be getting enough of those.

 

So Ray, special deals on this red ecoweb???

 

In my last greenhouse I built a wet wall out of the reusable air filters. Similar to ecoweb but more open. I stacked them about 4 thick and pumped a lot of water through them. Worked quite well.

 

Email me directly; we'll talk.