using peltier for cooling jackets

Using Arduino Project Guidance
1

hi. Im a student and im thinking of building a jacket that cools you down depending on the heat index or your core body temperature. Im thinking of using a peltier colling module, a thermistor, a battery supply and arduino..
the number of peltiers will be 9pcs located on different parts of the jacket..
the problems are:

  1. should I connect the peltiers series or parallel? Ive read some forums that I need to connect it in series so that the current stays at 6A on all peltier. the peltier that I will be using Operates from 0~15.2V and 0~6A.

I would not be using the maximum temperature it can provide. most likely I will be needing not lower than 15 degrees celcius.

  1. what MOSFET should I use? I googled some connections of cooling system and they use MOSFETs.. I was thingking,, what was this MOSFET for in this system? hahaha. sorry for being dumb..

  2. what battery rating should I use to? I thingking of a portable/compact rechargable battery for the jacket.. and with LONGER LIFE. I was thinking of 4-6 hrs? if possible..

  3. should I just connect it like peltier to mosfet to arduino? I really have no idea regarding this..

  4. how will I program it so that it can stay not beyond 15 deg cel? should I just use the normal For Int loop and If else?

thank you for your thoughts.. I really really need it.

2

I would suggest you calculate battery life based on running 6 units. at 12 volts at 6 amps for one hour.

determine the battery size needed.

and if the project would work based on the batteries.

3

You can learn here on how to control the peltier using Arduino with MOSFET, you need logic level MOSFET.
http://garagelab.com/profiles/blogs/how-to-use-a-peltier-with-arduino

For Battery, Lithium-ion have 128 Wh/kg,
if you running 6 units. at 12 volts at 6 amps that will be 432 Wh
For Lithium-ion battery, that will be 432 / 128 Wh/Kg = 3.375 Kg per hour of usage.
for 4 hrs will be 13.5 Kg, 6 hrs will be 20.25 Kg, just for the weight of the battery.

peltier need heat sink too, so don't forget the weight of the heat sink.

4

This isn't the route to go for completing what you want to do. It's going to be hard to use them to pull heat from the body and keep them from burning up. The human skin will decrease in temp when sweating so that will throw you off too.

You can save weight by not using old lithium ion battery's but instead use new tech in lipo batteries that have about 200 wh/kg

5

The problem is, where will the peltiers put the heat from the hot side? How will you get that far enough away from the body to make any difference? Maybe the Peltier lives on a backpack and you circulate liquid through the coat.

The bigger problem is battery life. Peltiers take a huge amount of energy and aren't in the least bit efficient. Having enough battery power in something that a human wants to carry around may be a problem.

6

"If you leave the fridge open, the room will eventually get hotter."

Peltiers, and other cooling systems, move heat from one place/side to the other.
Because of efficiency, the heating effect is more than the cooling effect.
How are you removing that heat.
Leo..

7

Well first you need even cooling so you would have to run some type of tubing all through the jacket have a pump ect...second pelteirs burn through massive ammounts of energy...perhaps have them turn on and off as the coolant in the tubing rises? Third...you probably dont need 9, 2 or 3 would do it. Fourth locate them in a single location with the pump and put heatsinks and fans on them facing...the more air they get the cooler they will run and the more efficient they will be. And finaly i would suggest a large lipo something like what they use on large rc helicopters...more volage on the packs and a bucking converter could extend there run time.

8

well thanks guys for all your answers.. Ill re think of something else..

9

Ogmudbones:
Well first you need even cooling so you would have to run some type of tubing all through the jacket have a pump ect...second pelteirs burn through massive ammounts of energy...perhaps have them turn on and off as the coolant in the tubing rises? Third...you probably dont need 9, 2 or 3 would do it. Fourth locate them in a single location with the pump and put heatsinks and fans on them facing...the more air they get the cooler they will run and the more efficient they will be. And finaly i would suggest a large lipo something like what they use on large rc helicopters...more volage on the packs and a bucking converter could extend there run time.

well I dont get the part that I dont need 9 pcs. erm.. can you suggest something? and about locating on a single location with pump? I dont really get it? hahaha. does it looks like the one one the cpu's? the liquid cooling something as replacement for fans/heatsinks? sorry. nood here.. :smiley:

10

With any kind of cooling project using peltier devices, its important to determine what the cooling load is .
ie how much heat the peltiers will have to remove from the coat to make the wearer feel cooler.
You need to figure this out first.
But, as previous posters have indicated, peltier coolers are extremely inefficient at large scale cooling, and this will I suspect be the limitation with your project.
The battery needed to run the peltiers and the fans to remove the heat will be so big and heavy that no one will want to carry one around with them.

11

Ill re think of something else..

To remove heat from a person, a tub full of cool water works very well.

12

spanner28:
well thanks guys for all your answers.. Ill re think of something else..

There's already people putting fans in hats.

And of course there's the old-tech known as parasols.

Look into Seebeck Current, at how the junctions move heat.