Smaller 12V A/C options

[posplayr]

b. rock, Thanks for the confirmation. I'll use 1.5 gal/day for a standard van and bump it up to 3 gal/day for my situation where I might have an attached drive-away tent. I am in Tucson and swamp coolers are very effective in this part of the country.

And yes water consumption is of interest for extended stays. Based on the info I have ordered a larger 33 gal water tank (previously 22 gal) to better support the solar shower and swamp cooler requirements.

https://www.sportsmobileforum.com/fo...ter-28425.html

This tent is a much cheaper way to get living and standing space than a poptop tent.

OLPRO Campervan Awning Cubo Drive-away Fibreglass Poled

https://www.ebay.com/itm/264230163593

[b. rock]

Hmm. I was rumaging around HD this weekend and came across this:

https://www.homedepot.com/p/RYOBI-ON...F01K/312025245

If you pair that with fresh air through a roof fan - could be a cheap temporary solution.

[posplayr]

It has been in the mid 90's here in Tucson lately and having the swamp cooler going in the shop has been great. I think it is in the low 70's inside a brick shop and I'm running it on low.

The real question in my mind is how much cooling you can get out of a 1/2 ft^2 of media (frontal area) with the rooftop fan configuation?

I have been piecing parts together for my rooftop install, but have decided to go for a prototype cover before committing to a fiberglass mold. The main variable I'm looking at is total height. I'm shooting for 9"-10" of height which gives 5 .5" to 6.5" of media height (width is fixed at about 12"). I'm hoping this will do well. but if necessary I can raise that up further to possibly 12" for a fully open vent cover.

This water tank is the perfect size for what I'm planning (16"x21"x9" WxLxH). It will not have the slanted front but will certainly fit the bill to see get a baseline on cooling effectiveness.


https://www.ebay.com/itm/184318701755

[b. rock]

Yeah, that'll be the challenge. It'd almost be better to have it downstream of the fan so you can have a larger area to push through rather than pull through the smaller exterior.

[posplayr]

Originally Posted by b. rock

Yeah, that'll be the challenge. It'd almost be better to have it downstream of the fan so you can have a larger area to push through rather than pull through the smaller exterior.

I don't think the fan configuration will be an issue. All the swamp coolers we have on the roof of the house and the shop have the fans downstream of the media pads.

I'm basically mimicking the configuration of our house cooler which is very efficient. I just need a data point to see what it takes to scale down from 1800 ft^2 house down to a 60 ft^2 van.

The benefit of the air flowing through the media first is that you can have a single opening to the outside that only allows flow in that comes through the media. The old-style does this as well but a 3 sided 2" media pads. Our new one on the house is a single-sided 8" thick pad.

On the 3 sided coolers the entire bottom of the cooler is filled with water (10 ft^2 0 whereas with the single-sided the pan is only 8"x30" and so it is much more efficient to flush the water occasionally.

Anyhow this is why I want to do a simple prototype and do some measurements.

This is the Aerocool 6800 we have on the house. That grille on the right-hand side is the only entrance for air and the whole side is filled with the 8" thick media. I attached the expanded view so you can get a better I dea of the configuration.

To reiterate, the only place there is water is in the media and in a 12" tray (times the 30" width) just below it.

https://indoorcomfortsupply.com/aero...-purge-system/

[posplayr]

Oh boy! If you want to see an example of over-engineering this is classic. The author does provide examples of various configurations available from the web.

My guess is that the author is a student in some sort of industrial design and focuses the title on "military" applications presumable to justify the over "engineering". Unsurprisingly there are no calculations as to what performance-wise benefits he is trying to achieve?

This was posted in 2012 and notified teh reader to watch for updates? I see none

https://muellerdesignlab.wordpress.c...cooler-design/

[posplayr]

Just a quick field report on Evap cooler performance. We have had a very mild spring this year. Temps have been in the mid 80's to low 90's. Weather bug says it will be this way for the next 10 days still.

Anyway, I turned on the cooler in the large shop we have. (30'x40' with 12 ft ceilings) . There are two medium-size coolers designed to be run with the two 10' rollup doors open. Even with the doors, all closed the shop has a vent the entire length of one side of the building.

With the shop closed most of the time, I was amazed to find the inside temp at 65 degF with about 50% RH with one cooler set on low. I almost need to wear a sweater to work out there at night LOL.

Surely if/when the outside temps get up to 110-115 degF the inside temperature will rise in relation as well but we seem to be in this really sweet spot right now.

[b. rock]

How's the one in the van working out? Now that we're deeper into summer I'm guessing you've had a chance to try it out?

That muellerdesignlab.com is super overkill but quite impressive.

I am working on an industrial version of this at work:

https://www.youtube.com/watch?v=R_g4nT4a28U

Makes the gears turn a little about incorporating one into the van. Little complex but highly efficient and effective.

With the new high top, I'm not sure I'll be able to mount a fan on the roof anymore and still fit in our garage so I am starting to piece together some frame/underbody mounted ventilation ideas. It actually opens up some interesting thoughts on potential evap or other a/c options, if you get over the dirt/mud/salt/water exposure hurdle.

[posplayr]

Originally Posted by b. rock

How's the one in the van working out? Now that we're deeper into summer I'm guessing you've had a chance to try it out?

I have gotten totally distracted from the cooler with the Lithium upgrade. Getting things sorted in anticipation of (hopefully)receiving cell this month.

Coincidentally I just happened to be thinking about getting back to the cooler (while waiting for the cells). I do have most of the stuff I"in-house" now.

I'm also designing an Arduino-based temperature controller for the DC-DC charger and want to get the PCB designs done to get PCBs on order.

[posplayr]

Some newer developments in this arena.

This is a DIY three-component A/C where the condenser is mounted outside the the van. Still takes about 60 amp at 12V = 600Watts
The BEST Battery Powered AIR CONDITIONER For Van Life?

https://www.youtube.com/watch?v=i3dDpmyyLAk

This is a cheapo DIY that requires ICE. Use a Hayden oil cooler, water pump, fans and a bucket with some water to transfer cold (absence of heat) from the bucket to the oil cooler.

If you have a fridge that you can convert from refrigerator temp range to freezer temp range (to have a ready supply of ICE) this might be something to do in a pinch.

You could have say 6 (or more) of these ICE packs and rotate through them in pairs. So while there are two in the bucket you have your backups freezing down. The efficiency would probably be improved by insulating the water/ice bucket. No reason to leave it open to the heat of the van. I see this more of a directed evolution where you want some cool right in your face to fall asleep so I would not expect it to cool down the whole van and its outer skin.

https://www.youtube.com/watch?v=DERYsKnlKzA