help on cooling capacity of a peltier device

Discussion in 'The Projects Forum' started by diskdrivex, Dec 26, 2009.

  1. diskdrivex

    Thread Starter New Member

    Dec 26, 2009
    just to give an idea of my level of electronic knowledge i work at a best buy installing car stereos, remote start/alarm systems, and other car related stuff. i am also MECP basic certified, and not to brag but i think my level of knowledge exceeds my job requirements significantly. that being said dont feel the need to dumb this down a whole lot. on the other hand, reading some other post on this forum makes me feel like a child disassembling an old telephone.

    so on to my question. i have only recently learned what a peltier device is. im sure im behind the times, but i think they are the coolest thing. i immediatly thought of countless uses for them that im sure so many people before me have thought of already. the one thing i would really like to actually try is a sort of A/C for my tent.

    my tent is 8'x13' and about 6' in the center. the top center has a small "shelf" and a mesh opening in the roof. i thought if i could make an(i believe the term is..) air to air cooler, and use the principle of heat rising to make a fan that would blow cooler air down onto us while sending some heat out the top.

    i am pretty convinced the design is good enough, but im worried about a couple things. i have absolutely no experience with a peltier device. i dont know if the size i would need to produce enough cooling to be noticeable would be too big to be "camp worthy" and im not sure exactly how hot the air would be on the other side. im woried it could damage the tent.

    im not looking for some dramatic central air cooling results. and im not even sure i expect to be able to effectivly cool the whole tent. but if i could get a nice stream of air that was noticably cold, in a package under 1 cubic foot, that would be awesome.

    so if anyone understands all the math involved in the cooling capacity of peltiers, or is someone has enough experience using them could tell me if im on to something here let me know, thanks
  2. steveb

    Senior Member

    Jul 3, 2008
    You can do this, but it's not trivial to do this kind of design. The design needs to be worked out carefully. You will need fairly large devices, and perhaps will need a large number of them. Peltier coolers need to be carefully mounted between heat sinks so that heat can flow. You also need a good amount of electrical power. The devices will run safely if the system is designed carefully, but you need to be cautious because there can be thermal runaway due to parasitic heat generated by the device. It's best to have temperature monitors on the hotside and coldside of the device so that the power can be shut down if it overheats.

    I think most device manufacturers (Melcor comes to mind) provide design formulas and/or software that can be used. You'll need to do some research and careful design work, but it should be well within your ability, if you don't mind investing some time.

    Also, see attached paper for some hints. Your design will not need to be as complicated as shown here, but it's always good to have an example to look at.
  3. Duane P Wetick

    Active Member

    Apr 23, 2009
    I worked with Peltier effect chillers (Melcor) when it came time to design a chill block of aluminum for keeping a Reagent at 50 deg. F. They did the job...but at a cost, 350 watts of power were required. You are better off using the desert water bag method of evaporation (water soaked towels draped around) to keep your tent cool.

    Cheers, DPW [ Everyone's knowledge is in-complete...Albert Einstein]
  4. someonesdad

    Senior Member

    Jul 7, 2009
    I was going to say the same thing about power consumption. If you're camping, you likely won't have enough battery power to run the cooling device. If you are going to take something along, I'd suggest forgetting the idea of the thermoelectric cooler and try to find a power-efficient fan. Even a small draft can help cool you. The problem with fans is that they consume quite a bit of energy overnight.
  5. Andrew Leigh

    Active Member

    Sep 8, 2008

    have you researched "evaporative coolers".

  6. diskdrivex

    Thread Starter New Member

    Dec 26, 2009
    the problem with me and stuff like this is, i dont always go the more efficient route if its not the most fun route. as far as power consumption i dont mind too much because im usually at a camp ground. but cost does come in to play. i saw something else online using a water pump and ice bucket and some coppper tubing wraped around a fan that would probably be a lot more efficient. i just like tinkering and toying around with ideas. maybe ill still get a peltier to make a single can/bottle beverage cooler for my toolbox at work