User Tag List

Informational! Informational!:  0
Likes Likes:  0
Page 2 of 5 FirstFirst 12345 LastLast
Results 9 to 16 of 34

Thread: To peltier or not to peltier, that is the question

  1. #9
    Let's positive thinking! seedjar's Avatar
    Join Date
    Dec 2004
    Location
    Olympia, Washington
    Posts
    4,064
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Nice investigation Butch. I was just doing some reading on cooling systems on my breaks at work today. Has anyone ever done anything with absorption chillers? I'm very curious about the feasibility of building an at-home model.
    ~Joe
    o//~ Livin' like a bug ain't easy / My old clothes don't seem to fit me /
    I got little tiny bug feet / I don't really know what bugs eat /
    Don't want no one steppin' on me / Now I'm sympathizin' with fleas /
    Livin' like a bug ain't easy / Livin' like a bug ain't easy... o//~

  2. #10
    Av8tor1's Avatar
    Join Date
    Jan 2007
    Posts
    4,811
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Dash,

    The hot side is just a few degrees above ambient. I don’t believe any more can be done on that side. Now on the cooling side, yes if it had a fan on it the delta T would decrease and efficiency would increase.

    If i understand your statements correctly, yes... the efficiency of the peltier module is inversely proportional to the DeltaT max form the hot side to cold side. The greater this difference the lower the efficiency.

    Also, the greater the temp differential the greater the heat transfer (ref. the peltier to ambient)... so this comes into play as well. It also has to do with emissivity, reflectivity, absorbtivity and transmissivty of the materials in question and the temp differentials.

    Thanks seed, and i don’t know... but if it is what i think it is, then i don’t think it would be feasible. But I honestly don’t know.

    Butch

  3. #11
    Millipede's Avatar
    Join Date
    Mar 2009
    Location
    oregon
    Posts
    755
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    what the heck is a peltier?

  4. #12
    Let's positive thinking! seedjar's Avatar
    Join Date
    Dec 2004
    Location
    Olympia, Washington
    Posts
    4,064
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    It's an electrical device that produces a cooling effect with no moving parts. When you electrify certain metals sandwiched together just right, one side of the stack gets hot, and the other side gets cold. It's called a thermoelectric or Peltier effect, named after the scientist that discovered it.
    ~Joe
    o//~ Livin' like a bug ain't easy / My old clothes don't seem to fit me /
    I got little tiny bug feet / I don't really know what bugs eat /
    Don't want no one steppin' on me / Now I'm sympathizin' with fleas /
    Livin' like a bug ain't easy / Livin' like a bug ain't easy... o//~

  5. #13
    Av8tor1's Avatar
    Join Date
    Jan 2007
    Posts
    4,811
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Joe, I looked up absorption cooling... and yes it’s what I thought. I’ve only had dealings with a couple over the years and they were in travel trailers (Winnabago type)

    My main concern would be the Anhydrous Ammonia. While I’ve only had a couple dealings with absorption systems, I've had a lot of dealings with industrial NH3/NH4 systems. (former hazmat responder and incident commander)

    That stuff is wicked, I’ve put the bubble suit on several times to go in and fix leaks.. Just a few PPM's and you can’t stand it, somewhere around 450 (IIRC it's been quite a few years) is lethal

    The two I worked on, I had to turn upside down and let them sit over night. Evidently they get a gas pocket trapped somehow and turning them upside down allowed it to escape

    I didn’t have a clue what I was doing. Luckily back then I knew someone who did.

    Personally, I would not want a NH3/NH4 system anywhere near my house. I have felt the sting of its bite

    Butch

  6. #14
    Let's positive thinking! seedjar's Avatar
    Join Date
    Dec 2004
    Location
    Olympia, Washington
    Posts
    4,064
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Yeah, it seemed a little too good to be true. But if I were to build one, it would be outdoors - the only part that would be near an enclosed space would be an external heat exchanger, to circulate cold water or some other coolant back indoors. Glad to hear your thoughts on it though. I should be happy with Peltier units, but there's something about 10% efficiency that I find very unattractive.
    ~Joe
    o//~ Livin' like a bug ain't easy / My old clothes don't seem to fit me /
    I got little tiny bug feet / I don't really know what bugs eat /
    Don't want no one steppin' on me / Now I'm sympathizin' with fleas /
    Livin' like a bug ain't easy / Livin' like a bug ain't easy... o//~

  7. #15
    Av8tor1's Avatar
    Join Date
    Jan 2007
    Posts
    4,811
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)

    Load performance test

    10 gallon load test, no insulation (on purpose).

    Start:


    One hour run time:


    After one hour, temps are still dropping but at a very slow rate... I started to graph it out, but it was like watching water boil...

    I would estimate a mid 50f temp to be very likely after several hours

    Obviously, insulating the sides, back and bottom would improve performance, as would downsizing to a 5 gallon tank.

  8. #16
    Let's positive thinking! seedjar's Avatar
    Join Date
    Dec 2004
    Location
    Olympia, Washington
    Posts
    4,064
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Hey, you stole my thermometer!
    ~Joe
    o//~ Livin' like a bug ain't easy / My old clothes don't seem to fit me /
    I got little tiny bug feet / I don't really know what bugs eat /
    Don't want no one steppin' on me / Now I'm sympathizin' with fleas /
    Livin' like a bug ain't easy / Livin' like a bug ain't easy... o//~

Page 2 of 5 FirstFirst 12345 LastLast

Similar Threads

  1. ? question ?
    By superimposedhope in forum Tropical Pitcher Plants  (Nepenthes)
    Replies: 6
    Last Post: 11-06-2004, 11:37 PM
  2. Peltier Cooling System
    By lithopsman in forum Greenhouses, Terrariums and Bog Gardens
    Replies: 13
    Last Post: 06-30-2004, 01:12 PM
  3. Peltier junctions thermocooling
    By heliguy in forum Carnivorous Plant Trading Post
    Replies: 8
    Last Post: 05-25-2004, 04:06 AM
  4. Peltier junctions thermocooling
    By heliguy in forum Greenhouses, Terrariums and Bog Gardens
    Replies: 1
    Last Post: 05-23-2004, 04:05 PM
  5. Peltier cell questions
    By lithopsman in forum Greenhouses, Terrariums and Bog Gardens
    Replies: 29
    Last Post: 12-10-2003, 11:34 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •