Staying cool with out air conditioning
 

I would like to build a modular seat cooler. Modular for 3 reasons, one I don't want to build it all at once, I want to be able to use 1 in multiple vehicles and 3 some part of this rig may start leaking (yes it will be full of liquid).

This is using targeted ice and water to stay cool.
The numbers say it could work.
10lb of ice will require some where around 1,440BTUs to melt all that ice. Then require an additional 100BTUs to warm the water from freezing to the minimum useable cooling temperature which we will say is 42'F.
So 10 pounds of ice gives us an number we will just round to 1,500BTUs.
At rest I believe a person puts off something like 400 BTUs per hour at rest and 500 to 600 per hour walking around.
So in theory you could cool your seat for a few hours with 10 pounds of ice (plus some added water to start the heat transfer).
That should work great if you were only trying to cool your back and bottom.

This device will be powered by very small amount of intermittent 12 volt vehicle power and the ice will obviously be frozen elsewhere.

The description will start behind the scenes moving to the outer covering. From the cooler, pump, controller to plumbing and what covers it.

For my cold reservoir I have an old tall narrow party cooler with its lid broken off that would be perfect for this. I want it tall because I would like to attach the pump to the cooler and it would be advantageous to put the pump hardware above the water line. I would like to maybe put the pump inside the cooler for added sound control.
It even has a drain plug for easy removal of spent ice.

The pump I want to use will be a sureflo diaphragm pump. These surflow pumps typically produce 1 to 2 gallons per minute up to 60psi and draw 2 or 3 amps. This system should operate at less than 15psi.
The pump has a built in adjustable pressure switch that I will set low to turn off the pump in case of a pinched main line.

The controls, 2 gallons per minute is just about the entire mass of the cooling reservoir so there is no need to run the pump continuously. Plus the pump will hopefully be inside the cooler so it doesn't need to put off any additional heat.
Good news is there is something specifically designed for a 12 volt application to cycle a pump on and off. Its called a adjustable livewell timer. It cycles a boats live well air pump or live well water pump on and off to save battery power and keep dinner alive.
These timers typically run for 30 seconds, then stay off for a variable amount time, that can be set from a few seconds up to 5 minutes.
30 seconds on and a minute or 2 off should be more than enough.
So simple a drunk redneck can wire it up and get it correct, first try.

To get the cool water from the cooler to the seat I was going to use 3/8'' silicone heater hose I have left over from another project. Its very plush, flexible and kink resistant.

To get the cold water to person interface going I am going to use 4mm lines under the seat. The collector lines will be 7mm and the cross lines will be 4mm. They are thin, you can sit on them and not even feel them and I have like 30 feet of soft made in Germany 4mm soft PVC line.
Run the water in parallel loops using these:
http://ecomodder.com/forum/attachmen...1&d=1437537107
http://ecomodder.com/forum/attachmen...1&d=1437537107
Tie the lines and tees to a plastic mesh backing with some padding.
I will have to pick up some odd size 7mm line and that's about it.

To cover it I was going to take the zip up cover to one of my dogs beds, wash it a few times and use it. Its already the correct size, shape and material.

We are pretty sure this doesn't work:
http://ecomodder.com/forum/showthrea...ers-32359.html

We must salute dremd for paving the way for how to do this, 7 years ago. Here: http://ecomodder.com/forum/showthrea...ject-3884.html

Sounds like a fun project. I look forward to pics. :)

I have a left over foot valve from a chemical pumping setup I will use as a pickup.
A foot valve is just a gravity check ball inside of a weighted body with a strainer around it.
Then poach the 1gpm surflo pump from my water injection setup. I would like to upgrade my water injection pump to a 3gpm pump. Now I have an excuse.

They make a T-shirt with cooling tubes built in. I have considered that but I have to get in and out 100 times a day so disconnect and reconnect would be a messy pain. Just cooling the seat is a good idea.

ice/water storage volume vs heat transfer
 

The larger the cooler size the greater the cooling mass per unit of surface area you get as far as loosing ice in the cooler itself.
Doubling the size would cut heat transfer to 1/4th with no more R-Factor in the cooler's envelope.(same wall thickness).

Don't know if a $15 bilge pump would put out the pressure you need but be easy to test, go buy one hook up a hose and see how high it can pump. Take it back to walmart if it isn't up to the task. I'd freeze 1/2 gallon milk jugs or 32 oz Gatorade bottles instead of loose ice. No need to drain the water.

Or go manual pump and use a squeeze bulb from a boat fuel tank.

Last idea cordless drill with $7 pump, pull the trigger when you need some more cooling.

Kool Ties are cheap ($11) and easy - and very effective:

Kafka's Kool Tie - REI.com

http://www.rei.com/zoom/nn/af67c870-...9beb85.jpg/440

Soak them in water, and the beads inside swell up and hold quite a bit of water right against your neck. It lasts several hours, and they work well.

This is what I was working on today.
Removed my old water injection pump. Then screwed it to the top of my old cooler.
I stuck a 6 foot long length of new premium fuel line, I wasn't going to cut it down. Then on the discharge end I put a 1/4''OD push fitting and a little length of line.
I measured it putting out a half gallon of water per minute powered by my jump starter pack.
Installing a shorter length of 1/2''ID line will greatly reduce suction lift head and going to 3/8''OD or 8mmOD line on the discharge and powering it with full 14.4v power should help.
Even a half gallon per minute should be more than enough.

http://ecomodder.com/forum/attachmen...4&d=1437628039

I did I very simple proof of concept functional check.
Took the cooler put almost enough water to cover the foot valve and about 3 to 4lb ice in it, ran 10 feet of 1/4 inch line to a Y splitter then stuck 10 more feet on each end of the Y then just looped everything together where I could sit on it and ran the 2 ends of the Y back to the cooler. It works a lot better than I thought it would.
I am using about 1/3 to 1/4 of line I am planning on using in the bottom part of the seat.
I want the seat cooler to have the ability to make the seat occupier uncomfortably cold on a 109'F day, then just turn down the pump cycle timer as needed or just turn it off all together.
After this test I would be shocked if it didn't work extraordinarily well.
The cooler should hold at least 20lb of ice.

In other news I picked up my upgrade water injection pump, 2gpm 60psi Delanvan "assembled in USA" extreme duty 12v pump. I thought it was $90, rang up at $150. It was in the wrong spot, just like everything else on a shelf at tractorsupply.
The bigger pump is to handle the expanded water injection roll I have planned.

After an hour of very cool bum the ice melted.
I put almost a gallon of room temperature water in the bottom to start off the cycle then put around 3 or 4 pounds of ice in there.
The lines running to and from the cooler were uncovered too, collecting condensation and I ran the pump constantly. This adding additional heat to the ice.
So the ice lasts longer than I thought it would.
With efficiency add ons like covering the exposed lines and cycling the pump the ice should last even longer.

Toward the last of the ice I tried cycling the pump on and off.
To swap the warm water out for cold through 20 feet of line takes maybe 10 seconds. Then stays cool for around 2 to 3 minutes.
A live well pump timer runs 30 seconds on then stays off up to 5 minutes.
So the live well timer I was thinking about using should be perfect.

My amp meter says the pump draws a little under 2 amps at 11 volts (the jump pack is getting low on power).
If we say the pump runs for 30 seconds then stays off for say 90 seconds.
At most its only average of a half amp.
Even 30 seconds on, 30 off is 1 amp average, so it will work well with an alt delete. It will use a fraction of the power of the A/C where you need a few amps to energize the magnetic compressor clutch, then 10 to 20 amps to run the blower fan.

The numbers say it should work well, in practice it works a lot better than I ever expected.
I am not often surprised like this.

would using peitier plates eliminate the need for ice? use closed loop liquid. I can't seem to think of a way to remove heat with a cabin mounted system without being over complicated. extra cabin heat could make it unbearable but it already is sometimes.
has condensation been thought of? NM might not have a lot of humidity but this close to the Gulf we do.
look forward to seeing a working model.

It has some condensation, I don't think its bad enough to cause any problems.
In NM it has been one of the wettest years on record so far and very humid this year swap coolers are useless.

As far as the working model I am still working on the cooler. I rounded up all my supplies for my cold reservoir and I think I finely settled on a expandable modular design.

i will stay tuned because i see potential.

This is what I am doing with the cooler so far.
The pickup tube is 1/2''ID braded PVC.
The discharge is a 3/8''OD that is expandable with lines that branch off and go up and out of the cooler with with 8mmOD lines. The tee fitting with a plug shoved in it is there for future expansion, the 3/8''OD line will act kind of like a manifold. As I need more cold water outlets I can add them as needed.
The return in the middle of the lid is 3/8''OD.
All the pressurized line in side the cooler is stiff polyurethane.
Not sure what to do with the wiring, might use a gland seal.
http://ecomodder.com/forum/attachmen...1&d=1437803923
http://ecomodder.com/forum/attachmen...1&d=1437803923
I am using the good SMC brand connectors. They are not the cheapest but they are the best I know of. I ordered a bunch of them off ebay.
Just search "SMC tee" and select business industrial. Zoro has a lot of them.

cool! pun intended!

For the seat I was going to copy this:
http://ecomodder.com/forum/showthrea...tml#post185174
No original thought what so ever.
And cover it with my dogs zip up bed cover.
Only differences will be I will use a ton more tube, 8mmOD feed, 3/8''OD return, a bunch of tee splitters, more paralleling and go completely over board with 1/4''OD tube and try to use up the 4mmID tubing I have. I want to put about 40 to 60 feet of line in just the lower part of the seat.
1/4''OD tube is cheap.

Just wondering if you'll get condensation on the outside of your tubes leading to wet seats?

Sure there will be some condensation but noting like wet seats like you get from when you leave a window down in the rain.

Could you add one of these to a beaded seat cover? I thought that was the Ecomodder method of preventing sweaty seats! :)

Peltier
 

The Peltier junctions are terribly inefficient.You might have to piggy-back them ,where each is rejecting heat to the one downstream.
Or run an inverter to power a wall-mounted water cooling fountain compressor/heat exchanger/etc. to create chilled water enough to handle the 300-400 Btu's/hour basal metabolic heat load.

Here's something that may generate some creative ideas. A year or two ago I bought a chilipad. Check out www.chilitechnology.com for info. A peltier unit is in a cube (about 10" cube) that generates cooled or heated water which is circulated through tiny silicone tubes built into in a mattress pad. The tubes are barely detectible even without only a sheet on top.

It does feel slightly wet sometimes but it is so slight, I feel a fan blowing through the seat would take care of it. No mold or mildew even in the humid south where I live.

It definitely works in the summer. As I have two dachshunds who stick to me like velcro, I don't need it in the winter.

I think a combination of chilled water circulated through a pad PLUS a bit of air moving across the tubes will cool the driver plus handle any condensate.

How about making a seat of out aluminum tubing, so it is structural and light,
and circulate the cold water in that.

My own idea is to just cool the back of your neck, this cools the blood which has a built-in circulation pump. If this pump is not working, a/c is not a concern. ;)

that's a good idea. i run across them from time to time.

I started 6 branches, might add a 7th, then attached 30 feet of 1/4''OD PVC tube on my 13x22 inch bottom pad.
I am sure I will get at least 30 to 50 more feet on there.
Also might extend the pad several more inches for under leg cooling.
Shouldn't be too difficult to get that uncomfortable cooling I am after, I can always turn it down from there and you cant use cooling capacity that you don't have.

Oil pan, thanks for this write up.:thumbup:

I think I'm going to follow your build and make one of these for myself. My Talons
mid mount turbo system is working great but the heat is killing me.:(

This will be a excellent way to keep cool. We have had one of our hottest Summers this year and its taking its toll on my body and check book.

Staying cool with air conditioning.

http://i70.photobucket.com/albums/i1...ps5b196323.jpg

https://www.youtube.com/watch?v=Vgi6W0vevOc

No A/C and cool as hell, but still I doubt whether the FE is much improved.

City mileage would be impaired, but hey, if you get in an accident, nobody will know if you wet yourself.

The first part of the bottom heat exchanger has taken 80 feet of 1/4''OD PVC. That's not counting the feed and return lines hanging off the side.
Seems adequate.

Got pics?

Almost all the surface of the 13x22 backing I used is covered with 1/4''OD PVC line that will have water flowing through it (no spacer lines used).
Yes I will get a picture of it up here pretty soon.

Almost all the surface of the 13x22 backing I used is covered with 1/4''OD PVC line that will have water flowing through it (no spacer lines used).
Yes I will get a picture of it up here pretty soon.

I went from 30 feet of randomly coiled tube in the quick and dirty proof of concept test to between 80 to 90 feet of tightly packed fairly uniform tube as you see here.
On the left you have all the return lines, on the right is the feed line.
http://ecomodder.com/forum/attachmen...1&d=1438384263
Remember, this is just one section out of as many as 2 to 4 sections. :eek:
If this doesn't do it I don't know what will.

On the subject of 11mmID line, it can be rather difficult to find. So I just used some 3/8''ID rubber fuel line.
3/8''ID PVC will not fit over the 11mm barb.
This little number has 11mmID ends with double 1/4''OD outlets, I bought 20 of them for cheap.
http://ecomodder.com/forum/attachmen...1&d=1438817737
These are going to my return manifold.

Then today this finely came in:
http://ecomodder.com/forum/attachmen...1&d=1438820134

I must say it actually works. At least the fan cooling part.
Its not exactly like sitting on ice water chilled PVC lines but it beats the heck out of nothing.
I mainly wanted it for the heating function for this winter.
All for only $50 shipped to your door (USA).

I figure if condensation were to be a problem with the ice water cooling rig I would simply put my ice cooled rig over top of this and use the fan portion and maybe some heat to dry the seat cooler when its not running ice water through it.

I tested the PVC loop pad.
First I tested the loop drains to make sure they all flowed a some what even amount of water and they did.
Then put ice on the water and sat on it.
After 20 minutes it was uncomfortable and after 30 minutes it was cold enough to start to be painful.

Hah, so what is the plan of action then? Use a PWM circuit to dial down the flow after a while?

The surflo pumps warn against giving them reduced voltage.
I was simply going to use a bass boat live well pump cycler.
These timers are built specifically to cycle small 12 pumps like this on and off to keep your catch or your bate alive and your boats battery from getting drained.
What this battery saving pump timer does is turn on the air or water circulating pump to a boats live well for 30 seconds, then it cycles off for a selectable time any where from a few seconds up to 5 minutes.
The contacts are rated for 10 amps, my surflo running under almost no pressure draws about 2 amps.
Since this little project is coming along so well I went ahead and ordered one last night. It was only $35 with shipping.

I also noticed my little cooler can become really full of spent ice, so full that I don't really see how I will be able to dump it with out unhooking everything from it.
I could just scoop out the water with a cup, if there wasn't several inches of ice on top.
Since I am going to run water injection it would make more sense to be able to pump that water into the water injection tank. So I think I will install a 3-way solenoid valve to the send the return water back out through a dump port.

here's an interesting article on instructibles that might have some info.
Refrigerator Shirt

This isn't related to cooling your shirt or seat. But a swamp cooler could be an option in keeping the interior cool.

https://en.wikipedia.org/wiki/Evaporative_cooler

https://upload.wikimedia.org/wikiped...otated.svg.png

It adds moisture in the air which could be an issue in some cases.

Old VW's used to have them on the outside, but I guess you could find some space to mount them somewhere away from the air stream.

http://www.pakwheels.com/forums/atta...3ae2f3b6e4.jpg