cooling your tent or van

kman · Post by **kman** » Sat Jul 17, 2010 11:58 pm

FIGJAM wrote:Great job! The T I bought fit INSIDE the drip line so it was easier to work with.

The water consumtion on the bucket cooler is 2gal. for 5 hrs.

Other than that..............KIGJAM...........Kman Is Good Just Ask Me.

Thanks!

I tried to find inside-the-hose T-couplings, but couldn't find any, locally. Found one on Amazon, but didn't seem worth like $5 shipping for a $2 part when I could buy it for $1.50 locally. Oops, I think I left that off the parts list, too, not that it can't be inferred, I hope...

That's right, on the water consumption. I wish I could edit my post and change it, but since it's been over an hour I can't anymore.

FIGJAM · Post by **FIGJAM** » Sun Jul 18, 2010 5:07 am

In the same isle where the drip conectors are at home depot is where I got the T. The one I got for the second bucket cooler, was hanging with the brass fittings in the same isle, and was white plastic.
The T you used is a booger to reuse.
The one I used, you can slit the line to get it off, then reuse the T.

FIGJAM · Post by **FIGJAM** » Sun Jul 18, 2010 7:16 am

Try to keep the vent hose that connects to the structure as short as possible.
I long vent hose to the structure will loose some of its cool.

FIGJAM · Post by **FIGJAM** » Tue Jul 20, 2010 8:14 am

ConnieH · Post by **ConnieH** » Tue Jul 20, 2010 11:19 am

So I tested my cooler in my shed over the weekend with mixed results. The shed is about 8x10, finished inside (and possibly insulated, I don't know). First I tested it with the fans inline, one on the lid of the cooler, the other at the end of the vent hose, which wasn't extended beyond bending it to a 90 degree angle so the end of the vent was vertical. I set the cooler on a table outside and put the fan through the open window and built a shroud out of 2" thick foam pieces around the fan to keep out outside air. Air blowing from the fan in the window was about 75 degrees, but there was little to no cooling of the rest of the space. It was 95-99 degrees on Saturday, inside the shed was close to that.

On Sunday, I took off the cooler lid and inline fan assembly and mounted my two extra fans side-by-side on the end of a cardboard box, then set the open end of the box on top of the bucket. It wasn't perfectly sealed, but it worked for a temporary test. I put the fans in the window and adjusted the shroud. This set up seemed to cool the shed a bit better, at one point it was under 90 in there (bearable considering that shed normally cooks).

One thing I did different on Sunday was that I started the cooler a little bit earlier in the day so the shed wasn't quite as heated up as it was on Saturday. Not sure if that made the difference, or if it was the two fans side by side.

My conclusions are that the side-by-side 64cfm fans work better than mounting them inline, but even those don't seem to be enough. I *might* go with 3 fans, but the extra noise and amp draw, while still minimal, has me leaning toward just springing for a higher cfm fan and donated the 64cfm fans to friends who want to build coolers for smaller spaces. Or I may use one as an exhaust fan in the yurt.

One question I have - since the cooler was at window level for my test, does anyone think that may have had an affect on the cooling of the shed? Should the cool air come from lower toward the ground, or higher toward the ceiling, rather than halfway up the wall? When we install it in the yurt, I had planned to put the vent at about 2' up the wall - or whatever the height is of the bucket with the vent assembly on top of it, the bucket will sit on the ground.

FIGJAM · Post by **FIGJAM** » Tue Jul 20, 2010 12:20 pm

What was the humidity outside like? It realy makes a huge difference in how well the cooler can work.

You are going through the same thing with your fans that I did. Thats why I tested so many. I think you are suffering from cfm deficiency. Im still convinced that the bucket is big enough. Just need alot more air circulating through your pad.

Were you venting air out of the shed? VERY important to do this! The air has to be able to circulate Through the space.

What size vent hose do you have available? You said you had alot and Im wondering if you have more than one size. Maybe 8" comming off the top of the bucket with the fan or aray of fans in the wall of the yurt.

Dont give up. If all else fails, Im coming to your camp anyway so Ill fix it or grovel at your feet to forgive me for putting you through this ordeal.

FIGJAM · Post by **FIGJAM** » Tue Jul 20, 2010 1:44 pm

Oh, set the cooler up close to your bed. That way if it doesnt cool the whole structure, It will keep you cool for napping.

ConnieH · Post by **ConnieH** » Tue Jul 20, 2010 1:50 pm

haahaa - no groveling required! I love this kind of challenge and you deserve many thanks for answering questions and sharing your knowledge. I love tinkering and experimenting even if the result ends up in the trash, it's the hands-on learning experience that is so valuable...and as it turns out it's a bit of a relationship builder, too, since the bf and I don't always see eye to eye on how things should be done, so we are learning how to work together constructively instead of the "you're doing it wrong" jerk scenario I spent 10 years in

But I digress...

The humidity was around 13%. I think the bucket is big enough too, it could have been that it was too close to the shed and in a somewhat partially shaded area - I'll try it again this weekend on the other window that is in full sun all day. The hose I'm currently using is a 4" flexible aluminum dryer hose, cut in half so there isn't as many "creases"...I don't like it, but it fit the inline fan method perfectly and was cheap. It seems reasonable to me that a smoother pipe might be better, like the one in your first prototype. I have an 8" a/c vent piece leftover from something that I may try to retrofit, but I need to go the plumbing store for fittings for the reserve tank anyway, so I may pick up something else that could also accommodate a 120mm fan if I go that route (which is likely!).

FIGJAM · Post by **FIGJAM** » Tue Jul 20, 2010 1:59 pm

Try to find a fan with the most cfm, high rpm, under 1amp that you can. Gots to move that air if you gonna be cool.

You may still need to upgrade to the box cooler for that size space.

FIGJAM · Post by **FIGJAM** » Wed Jul 21, 2010 12:39 pm

kman · Post by **kman** » Wed Jul 21, 2010 9:59 pm

Incidentally, the Cen-Tech no-contact temperature meter FigJam is using in the photos above is on sale at Harbor Freight for $10, is anyone wants one.

I hope to run a better test of my bucket cooler this weekend, complete with temp measurements.

ConnieH · Post by **ConnieH** » Thu Jul 22, 2010 8:17 am

I found a fan online that is 4100rpm 190 cfm 1.25 amps, $19.99...does that seem a bit too much for the bucket? Or maybe add bigger holes in the tubing to compensate for the bigger fan? Not sure if I'll order it, but am considering it.

That temp meter is cool, and I need to return some things to HF, so I may get one - my meat thermometer method probably isn't all that accurate

kman · Post by **kman** » Thu Jul 22, 2010 8:37 am

ConnieH wrote:I found a fan online that is 4100rpm 190 cfm 1.25 amps, $19.99...does that seem a bit too much for the bucket? Or maybe add bigger holes in the tubing to compensate for the bigger fan? Not sure if I'll order it, but am considering it.

That temp meter is cool, and I need to return some things to HF, so I may get one - my meat thermometer method probably isn't all that accurate

That's a lot more amperage than the smaller fans were drawing (1.25 vs. .35 for most 120mm fans), other than that I don't see why it wouldn't work. Might be kinda loud, though... 4100rpm is pretty fast. How large is it? Got a link?

FIGJAM · Post by **FIGJAM** » Thu Jul 22, 2010 8:52 am

It seems like a perfect balance between the smaller fans and just splurging on the endless breeze. I like it! Please post a link so we can see all the specs. I dont think the fan noise is going to be that noticeable compared to the sound of BM. You can always add more holes to the drip line.

ConnieH · Post by **ConnieH** » Thu Jul 22, 2010 8:55 am

Here's the link: http://www.axiontech.com/prdt.php?item=57484

55.5dBA vs. 41dBA for the 107cfm fan on the same website, so probably noisy, but that doesn't bother me so much since I usually sleep with earplugs anyway and I can sleep through just about anything, even the whomp-whomp sound camps.

FIGJAM · Post by **FIGJAM** » Thu Jul 22, 2010 9:15 am

It looks like the ideal fan. Its going to put the air exchange rate at the 5min. mark which is very good for maintaining comfort in the space. I can allways get warm enough, but its harder to get cool enough. So I like to over engineer.

Did a quick calculation for a house here.

1000sq. ft. home with a 3000cfm cooler.

8000 cubic ft. Air exchange is under 3min. I still think the 5 to 10min. range will work on the playa.

ConnieH · Post by **ConnieH** » Thu Jul 22, 2010 9:21 am

this one is interesting:

larger size-wise - just under 8 inches, but still small enough to fit on a bucket lid with a modified duct tube. It looks quiet too...

FIGJAM · Post by **FIGJAM** » Thu Jul 22, 2010 9:29 am

kman · Post by **kman** » Thu Jul 22, 2010 10:15 am

ConnieH wrote:this one is interesting:

larger size-wise - just under 8 inches, but still small enough to fit on a bucket lid with a modified duct tube. It looks quiet too...

The biggest problem with super-low RPM fans is they don't have enough oompf to push air when there are restrictions or a load. They're fine in perfect straight-through conditions (like the computer cases they were made for), but if you're trying to pull air through a thick filter (esp. one that's partially clogged with playa dust) and then push it through a couple feet of conduit, you need something that can push air with some power.

The spec to look at is the air pressure figure.

The 4000rpm fan (1.25A, 190cfm):
Air Pressure: 17.64 (wow, is that a typo?)

The 2000rpm CoolerMaster fans I bought (0.35A, 70cfm):
Air Pressure: 2.94 mmH20

The 1300rpm NZXT fan (.70A, 166cfm):
Air Pressure: 1.82 mm H2O

The 700 rpm CoolerMaster MegaFlow (0.28A, 110cfm):
Air Pressure: 0.595 mm H2O

I don't quite buy how that NZXT fan can really push 166cfm with those specs, but clearly, looking at the air pressure rating, it's a gutless wonder. That 4k rpm fan is off the charts, though. Tempting... but 55db is LOUD. And 1.25 amps is nearly twice the power pull than two of the 2k rpm fans (1.25A vs. 0.7A). Tough call... but I'm going to see how well I can make the two fans I already have (the 2k rpm 70cfm 0.35A fans) work, first.

kman · Post by **kman** » Thu Jul 22, 2010 10:27 am

I just found this fan, however, which looks pretty interesting (I found some reviews of the 4k Delta fan that mentioned this as a superior alternative):

http://www.scythe-usa.com/product/acc/0 ... etail.html

Available at Amazon for under $8:

ULTRA KAZE 120mm Case Fan 3000rpm, Model # DFS123812H-3000 (3000rpm version):

3,000 rpm
45.90dBA
133.60CFM
0.60 A

I couldn't find an air pressure rating, but reading between the lines of the specs I'd warrant it's pretty darned respectable, and noticably quieter than the 4k fan. And half the price (and in stock, not a special order). Frankly you could run two of these (1.2A total) and get a ton more output than one of the 4k delta fans, and use a smidge less power, too!

Shoot. Now I'm seriously considering picking up a pair of these as alternates to my lower speed quiet fans, in case they're not enough...

ConnieH · Post by **ConnieH** » Thu Jul 22, 2010 11:04 am

hmmm...that Scythe fan looks good, I like the lower amp draw. From looking at all these fans, the ones with better pressure are deeper than the ones I got, 38mm vs. 25mm, which makes sense. I might spring for one of the Scythe fans, depending on the results of this weekend's testing.

FIGJAM · Post by **FIGJAM** » Thu Jul 22, 2010 12:19 pm

I still like the look of the 190cfm, but it sounds like you two have more patience for research than I do......lol.....so have fun.

If you mount your fan on the lid of the bucket, then run the vent hose to the wall, you wont get that much noise in the yurt.

You can still put a remote switch on the wall of the yurt for inside controls.

kman · Post by **kman** » Thu Jul 22, 2010 12:52 pm

FIGJAM wrote:I still like the look of the 190cfm, but it sounds like you two have more patience for research than I do......lol.....so have fun.

If you mount your fan on the lid of the bucket, then run the vent hose to the wall, you wont get that much noise in the yurt.

You can still put a remote switch on the wall of the yurt for inside controls.

If I recall my acoustical physics correctly, a 3db increase = twice as loud.

So running two of the Scythe fans would be 3db louder than one fan.

Two Scythe fans:
48.90 dBA
267.20 CFM
1.20 A
$25.48 with shipping, in stock

One Delta 4k fan:
55.5 dBA.
190.48 CFM
1.25 A
$27.77 with shipping, but special order (how long to get one?)

6.6 db less noisy, so half, and half again, the noise of the one Delta, and a LOT more CFM... and a smidge less power and a couple bucks cheaper.

Power consumption is about equal to the Endless Breeze on low (1.18 A). Noisier, but 1/3-1/4 of the price. And you have the option of running one fan only if you need to conserve power, for half the power draw.

I'm thinking a pair of Scythe fans is the way to go!

In fact, I just ordered two.

I should get them next week sometime, so I'll post pics sometime the following weekend.

ConnieH · Post by **ConnieH** » Thu Jul 22, 2010 1:42 pm

kman wrote: ..............I'm thinking a pair of Scythe fans is the way to go!

In fact, I just ordered two. I should get them next week sometime, so I'll post pics sometime the following weekend.

Sweet - let us know how they perform! I did find the Delta fan on www.newegg.com for $29.99 (plus $5.99 shipping), so it is available should anyone want to order it. There are others similar to it on newegg, too, and you can search by airflow - cool site for research, but prices seem high on some stuff.

kman · Post by **kman** » Thu Jul 22, 2010 2:46 pm

Will do.

A quick refresher in acoustics, btw, shows me I may have been wrong about the 3db increase, however, I'd bet the difference should still be about half as loud for the pair of Scythe fans vs. the one Delta 4k fan.

The worst case interpretation of the data suggests two Scythe fans, pumping out 77 cfm more than the one Delta fan, at absolute worst would be about the same volume level as the Delta. (There is some debate as to whether the doubled level is 6dB or 10dB.)

On the other hand, looked at in another way, I may even have been right in the first place, so who knows?!

More than anyone wants to know on the subject here: http://www.sengpielaudio.com/calculator-levelchange.htm

Mr. Lucky · Post by **Mr. Lucky** » Fri Jul 23, 2010 8:42 am

I'm glad you guys are a week or so ahead of me. My coolmaster fans should arrive on Monday and shoot, it sounds like I need to upgrade already, based on Kman's and ConnieH's findings. Keep your experience and data coming. It's really helpful.

I'm determined to make a functioning system this year. I've had two failed attempts in prior years and my campmates just shake their heads now when I tell them that I'm making one that will really work.

My plan is to the 7gal bucket I already have in hopes that it will provide more wetted surface area. Since I have a 12v bilge pump that's an energy hog and more power than I need, I'm building the float switch like Case's to move the water up to a reserve tank. I planned on putting the two coolmasters on the top of the bucket with two hoses going in to the hexayurt.

Fig's suggestion to Connie to build a box-o-fans on the inside seems compelling (similar to Case's design). What do you think the trade offs are between having one hose or two?

BTW, I'd be interested in a swapcooler tour one (hot) afternoon, were we check out each others results. We're going to be at 4:30 and Detroit, Hippocampus - we do a french cafe in the mornings. Maybe we could meet up there as a starting point.

kman · Post by **kman** » Fri Jul 23, 2010 9:10 am

If you got the same CoolerMaster fans I did, Mr. Lucky, don't give up on them just yet. I think mounting two will give sufficient airflow. This weekend I need to figure out some way of making a shroud to focus the two fans, or at least pick up a dryer hose so I can do a decent test, especially now that I have a way of actually measuring the temp (the little Cen-Tech device... although now I'm wishing I had a way to measure cfm! LOL). Amazon lists the CoolerMasters at 90cfm, so I was pretty miffed when the actual packaging marked them as 70 cfm (69.something to be exact). Still, as long as you use two, that's 140cfm which should be enough... just not as much as the Scythe fans. The CoolerMasters are definitely nice and quiet, though... if you end up mounting them in the yurt wall instead of on the bucket (outside), you do NOT want a pair of stupidly loud fans (read: Scythe or Delta) running, so they'd be FAR better than the faster and louder fans in that application. (Particularly since you want it close to your bed for maximum effect). I think the Endless Breeze is the only other option I'd consider wall-mounting, for noise purposes, but it all comes down to how much power you have available... I went with the Scythe option given the relatively large size of a 6' yurt, I just don't see a more modest airflow making enough difference.

The little Harbor Freight solar pump rocks, though. I'm very glad for that. I do debate picking up the second (higher powered) pump that would run off 12v instead of solar, though, just in case something happens to the HF pump. Redundancy is good on the playa when the nearest electronics store is many hours away...

ConnieH · Post by **ConnieH** » Fri Jul 23, 2010 12:55 pm

Mr. Lucky wrote: BTW, I'd be interested in a swapcooler tour one (hot) afternoon, were we check out each others results. We're going to be at 4:30 and Detroit, Hippocampus - we do a french cafe in the mornings. Maybe we could meet up there as a starting point.

Yes - let's do it! We'll be just a block away from you at 4:30 & C in Farmopolis - home of the ManChanical Bull and Cornhole Bar.

I'm going to play with my 4 fans tonight, stacking two on top of each other, then the two sets next to each other, which should result in 123cfm and may increase the pressure - each of my fans has .28mmH20, so I'm not sure if it will double or quadruple or what, but I figure I can play with these until Kman reports on his new fans. Using all 4 fans will result in an amp draw of 1.72a, which I'm not happy about, but it's just an experiment at this point...I'll probably buy a new fan or two

These little guys will come in handy for something else, or I can use one as an exhaust fan in the yurt.

kman · Post by **kman** » Fri Jul 23, 2010 1:23 pm

I'm all for a swamp cooler meeting as well, although I'm far from you guys.

We're easy to find, though, we'll be at Prometheatrics (the tesseract/hypercube) at 8:00& Esplanade... ask for Kalani, and look for the yurts.

Best to try to figure a meeting time, though as I doubt I'll spend much time in camp except eating and sleeping...

No promises about being blue.

Trishntek · Post by **Trishntek** » Fri Jul 23, 2010 3:17 pm

kman wrote:
ConnieH wrote:this one is interesting:

larger size-wise - just under 8 inches, but still small enough to fit on a bucket lid with a modified duct tube. It looks quiet too...
The biggest problem with super-low RPM fans is they don't have enough oompf to push air when there are restrictions or a load. They're fine in perfect straight-through conditions (like the computer cases they were made for), but if you're trying to pull air through a thick filter (esp. one that's partially clogged with playa dust) and then push it through a couple feet of conduit, you need something that can push air with some power.

The spec to look at is the air pressure figure.

The 4000rpm fan (1.25A, 190cfm):
Air Pressure: 17.64 (wow, is that a typo?)

The 2000rpm CoolerMaster fans I bought (0.35A, 70cfm):
Air Pressure: 2.94 mmH20

The 1300rpm NZXT fan (.70A, 166cfm):
Air Pressure: 1.82 mm H2O

The 700 rpm CoolerMaster MegaFlow (0.28A, 110cfm):
Air Pressure: 0.595 mm H2O

I don't quite buy how that NZXT fan can really push 166cfm with those specs, but clearly, looking at the air pressure rating, it's a gutless wonder. That 4k rpm fan is off the charts, though. Tempting... but 55db is LOUD. And 1.25 amps is nearly twice the power pull than two of the 2k rpm fans (1.25A vs. 0.7A). Tough call... but I'm going to see how well I can make the two fans I already have (the 2k rpm 70cfm 0.35A fans) work, first.

The NZXT is a 200mm frame. I just bought a couple of 'em at Fry's. I've been lurking over you conversations for a few days and compared all the coolmasters along with the NZXT.

I also looked at insulated flexible duct at Dom Depot. 8" is what I would need and 25' is about $30. More length than I need, but that is how they sell it. I'm still debating whether to use that or go with some basic flexible duct and keep it short as possible.