cooling your tent or van

[Best]

Figjam,

First, hi, I camped across the street from you in 2016, thanks so much for all your advice.

Second, I'm getting the pvc part from right here:
https://www.theplayalabs.com/swamp-cooler
which references this thread a bunch.

If it's not too much trouble could you pm me a link to the proper piece that I should use (either in ABS or a toilet flange?) Sorry but I haven't built anything like this before and the whole process is causing me great stress because I've already bought incorrect stuff and I'm terrified of doing so again.

[FIGJAM]

Go to the plumbing section and look on the bottom shelf where the connector are.

https://www.homedepot.com/p/4-in-ABS-DW ... /100344957

[Canoe]

Here's some long shot questions before I commit to an experiment.

• How many square inches of Dura-Cool pad is required to allow the Endless Breeze fan to get close to or at its 900 CFM?
• How high can the pumps we're using lift water while still supplying enough flow to keep the pad wet for that 900 CFM?

[FIGJAM]

I've been using a 20"x20" register for the pad.

30"s on the little pump.

[Canoe]

Merci
I should have seen that.
I've got a pad that's 17x33, so only 561.

[Canoe]

Has anyone ever done anything to use the chilled reservoir water to pre-chill the incoming hot dry air?

[Popeye]

Has anyone ever done anything to use the chilled reservoir water to pre-chill the incoming hot dry air?

There is a thread on here about two stage evaporation.

[Canoe]

Has anyone ever done anything to use the chilled reservoir water to pre-chill the incoming hot dry air?

There is a thread on here about two stage evaporation.

I looked,... and only found a few posts on this thread. viewtopic.php?f=280&t=33842&start=3780#p1127484

Two stage (1st stage producing cool-dry air, 2nd stage is an evap cooler producing cool-wet air) seems to pre-cool hot-dry intake air for 2nd stage use by:

• a (1st stage dedicated) pre-chilling swampcooler's cool-wet air feeding an air-to-air heat-exchanger, or
• a 1st stage dedicated swampcooler's reservoir (or the 2nd stage reservoir) providing chilled reservoir water used in a liquid-to-air heat-exchanger, or
• 'chiller' using air-to-air heat-exchanger with water sprayed in one channel to chill that channel from chilled reservoir water & evap cooling, or
• other chiller source (using power).

I'm not convinced the lower output temperature or RH levels ~50% RH are worthwhile goals for playa use. 50% RH is better for comfort for a home, and the two-stage commercial units seem to include mixing with return air, so a lower temperature there is beneficial. A cooler output could help if a playa-cooler was trying to cool a larger space than it can properly handle, but why not use one of the larger designs or multiple of these simple reliable units.

As #2 above, if stage 1 was simply stage 2 chilled reservoir water run through a rad in front of the stage 2 pad, then the 50% RH output would suggest that this would use less water. If so, perhaps lowered water use is significant at home if running a meaningful portion of year-round (and if future water shortages), but likely not significant running five hours a day for a week on the playa.

We seem to be getting hugely great evaporative efficiency from the proven for-playa designs. I'm wondering if some of that is due to the chilled-water flowing over the pads providing some 'pre-cooling' benefit. (from cooler & reservoir water being at ambient temperature, how long from turn on until the cooler: chills the reservoir water, and is producing its max cooling) With chilled-water pumped from the reservoir, as the air enters the pad is it getting both pre-cooling from chilled water and evap cooling, and deeper in the pad it is already somewhat chilled as it finishes its evap cooling? This would mean we'd expect less improved results from moding a playa-cooler design to have intentional pre-chilled intake air using chilled reservoir water.

curious

[Popeye]

That's the thread I was thinking of. Sorry but I dont have any more info.

[Drizzt321]

So tried the 5 gallon bucket evap cooler for my 3rd year, unfortunately I don't think I had a fan with enough CFM. So years later I'm coming back around, going to try using 130CFM marine blower, in tests I just did at max pulled ~1.9-2.0A, planning on using a speed controller, so turning it down to ~0.3-0.5A for when I'm actually running it, which probably won't be most of the time. I'm thinking I'll add a 2nd bucket underneath with the water pump so I can have a whole lot of water as a reservoir and can easily enough add some nice if I want some cold, afternoon air Not going to cool my whole shelter, a 14' Shelter Systems dome, but enough so it can blow right across me, as well as have a temp or light sensor to automatically turn it on for the morning so perhaps I can sleep longer.

BTW, how would something like https://www.homedepot.com/p/Aspen-Snow- ... /301876067 be instead of the DuraCool pads?

[Canoe]

So tried the 5 gallon bucket evap cooler for my 3rd year, unfortunately I don't think I had a fan with enough CFM. So years later I'm coming back around, going to try using 130CFM marine blower, in tests I just did at max pulled ~1.9-2.0A, planning on using a speed controller, so turning it down to ~0.3-0.5A for when I'm actually running it, which probably won't be most of the time. I'm thinking I'll add a 2nd bucket underneath with the water pump so I can have a whole lot of water as a reservoir and can easily enough add some nice if I want some cold, afternoon air Not going to cool my whole shelter, a 14' Shelter Systems dome, but enough so it can blow right across me, as well as have a temp or light sensor to automatically turn it on for the morning so perhaps I can sleep longer.

BTW, how would something like https://www.homedepot.com/p/Aspen-Snow- ... /301876067 be instead of the DuraCool pads?

Alternate pads: I haven't used them, but from looking online, sometimes they work, sometimes they fall apart. This is a common story with alternate pads.
DuraCool pads are proven to work on the playa and have the playa dust washed off them as they're used.

The recommended fan is 190 CFM, and generates 17.74 mm H2O of static pressure, using 1.6A.
AFB1212SHE-CF00 190 cfm, 17.74 mm H2O, 1.6 A, 55.5 dBA, 4100 rpm

That Sea Flo fan doesn't publish the RPM nor a static pressure.

You substituted the first year and it didn't work out that well. So you're going to substitute again?

... I'm thinking I'll add a 2nd bucket underneath with the water pump so I can have a whole lot of water as a reservoir and can easily enough add some nice if I want some cold, afternoon air ...

p.s.
Bucket on bucket should work well, if your pump can lift the water up that high and at a rate that keeps the pads wet.
The cooling comes from the evaporative cooling, not from adding ice.

[asr9754]

It works best if you use the parts indicated in the design.

[Token]

Ultrasonic atomizers are the future

[Drizzt321]

Sure, I'll just get the proper DuraCool pads then

Double checking the pump, I almost certainly don't have a strong enough one. Might work OK, but probably not enough g/h. So I'll get the suggested ones. Worst case I can use both of them and pump up for separate 1/2s of the pads.

[Canoe]

And the fan needs to be able to generate static pressure so it can suck the air out of the space inside the bucket so it sucks air through the pad. Note the size of the blades, rpm and clearance to the housing on the recommended bucket-cooler fan "SHE".

If a fan manufacturer won't publish a fan's static pressure, that's usually because there's no meaningful static pressure. That fan likely sucks for use in a swamp-cooler, as it likely has little suck.

[metal450]

This may be a silly question, but every use of this design I've seen thus far places the bucket outside the living space, and ducts the cool air to the inside. Is there any reason not to just have the bucket itself inside the tent/van/RV? Then rather than sucking up the super-hot outside air, it's sucking up & recirculating the (already partially-cooled) inside air, no?

Then you could also just forego the ducting, set the thing on the floor, & have it blast the cool air straight up?

[FIGJAM]

The super hot outside air is what makes the cooler work so well.

If it sets inside it will just keep building up the humidity till it feels like Florida.

[metal450]

Hmm, interesting.

I stay in an RV, and had envisioned plopping it down in the middle of the floor as a way to avoid running the generator & burning gas unnecessarily. If it has to be outside though, I'm struggling to envision a route to get the ducting into the living area. What have other people tended to do - just get a super long flex hose, leave the door open, & run it up the stairs? Does that not leave the wide-open door to "leak" the cooled air right back out...?

[Captain Goddammit]

Actuality you need all the air to leak out. Swamp coolers are an entirely different concept.
You’d have to have something like a window or roof hatch or two open, the swamp cooler needs to continually replace the air in the cooled space.
You’ll need a pretty big swamp cooler to do a moderate sized RV and you’ll go through a lot of water.
AC is generally the way to cool an RV.

[metal450]

Ah, alright - maybe I'll just stick with the AC then. I just found another great thread discussing this (viewtopic.php?t=81327), & it looks like getting a feasible solution for an RV is actually far more involved than I'd envisioned (as you mentioned, requires a much larger unit & well-designed airflow).

Thanks for the quick feedback!

[Canoe]

For an RV, you get outstandingly less heat by covering the glass and roof vents/skylights/etc. with Reflectix. Find the RV tips thread. With that done, you'll use a lot less A/C, and you're in the range for a swamp-cooler to work.

Sitting a swamp-cooler on the ground is doable, but a pain to duct and get a strong enough fan to push the chilled air up; easy to do it wrong and it won't work.

A swamp-cooler installed inside the RV is much easier, and cheaper, but requires a somewhat different design and you must pay attention to detail. I've got a design that would sit on a table or floor (takes space), ducted from a window, but haven't built and tested it yet (waiting on pump), so too late for this year...

[metal450]

Yup, we reflectix all the windows already. (Except for the rooftop vents - we reflectix the ones in the bathroom & shower, which we don't use, & the other two in the front & rear we've installed AC filters so we can open them & let out the heat buildup). Still, always looking for ways to improve...especially after last year's crazy heat

[asr9754]

Metalhead,
Here's my setup for a trailer/RV with the swamp cooler: I pop out one glass window pane from the bed area. I cut an RMAX foam panel to fit into the window frame and wedge the foam panel in. Cut a circular hole in the foam to match the duct from the swamp cooler. I have to put the swamp cooler on a stool to lift it high enough to reach the window, but I get fresh cold air blowing right into my sleep space all week, it's pretty great!

[metal450]

Ooh, that does sound nice! Still, sounds like an RV will require a much larger size than the 5gal bucket original FIGJAM design. I didn't really understand the fundamentals of how swap coolers work - i.e. I was envisioning a "cool air blower," rather than "a device which needs enough flow to continuously replace all the air in the living space." Don't think I'll have time for such a large build, for this year's burn at least

[FIGJAM]

If you have a shelf in front of a window you can set this in the window and cool most of an RV.

Scroll down on this page.

Needs a bigger box for a big enough intake so the fan can breath freely.

viewtopic.php?f=280&t=33842&start=450


[metal450]

Whoa that's awesome...on my list for 2019!

[adkisson]

Here's a new design

[FIGJAM]

The basics are perfect.

It's a "unicooler" without the box.

It would work even better if air couldn't get around the edge of the pad.

If he had left the pad full size and tucked the excess in around the fan, it would help a little.

[highwing]

Open questions to the group about my cooler.. I had this box laying around and wanted to use it for the shell.. The pump and fan are from the original post. Since I had a piece of blue and a piece of the aspen stuff, I smashed those two together to form a double wide pad and wrapped it with plastic mesh. I also put some black pre-filter on the holes out to the side. The center column goes all the way up and is *slightly* compressed by the lid to make it a tight fit and the tube is slightly pushed into the middle of the two pads, helping the seal a bit as well. Ended up using a bit of AC ducting that screws into that white flange at the top. It's a good seal.. can pick up the whole thing once it's tightened in. Glued a bit of plastic on the top of the pump and added a float valve there that will turn off both the fan and the pump when the water gets too low.

So.. before I learn something really obvious once I'm there and am cursing at myself!.. anything about this design that seems like it's going to be a problem? I'm only cooling one of the smaller canvas tents (200ft^3 total).

Overall cooler

IMG_4529.JPG

Pad construction (and prefilter in background)

IMG_4528.JPG

Float valve

IMG_4524.JPG

[FIGJAM]

Turn the fan on then lift the lid.

If you can detect a change in fan speed, make your intake holes bigger till the fan can breathe freely.