small a/c or cooler

wxh3wxh3 Solar Expert Posts: 70 ✭✭✭✭
I have a small 24V standalone system: 270W, 110AH batt that currently does maybe 400 to 500Wh a day charging (lights, small electrics, inverter) when starting from fully charged, with occasional higher amounts. I am looking for a productive way to use my excess array power when I get consecutive sunny days.

The most obvious thing I think is cooling which I could run on a timer during sunny days.. However, it appears even the smallest 5000 btu window units require ~500W and have surge requirements much higher. I would obviously need to get maybe a 2000W inverter, although I wonder if it could be mod sine. My system just seems too small, even if I expand to 405W solar which I am considering. Maybe it is possible if I only run it 1 or 2 hours a day...

Another option is a small evap. cooler which I could use my existing system. I live in Dallas and it can get pretty dry in summer...also would be using in house with central air so not so humid. Anyone have any recommendations? I have seen some negative reviews of the small portable swamp coolers.

Thanks for any opinions.

Comments

  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: small a/c or cooler

    try thermoelectrics. they aren't real efficient, but you'll cool a small area i'm sure with enough of them and a diversion controller.
    http://www.melcor.com/tec.html
    if you can afford the costs try one of these, http://www.melcor.com/ssair.html
    let us know if you do this how well it works.
  • DapdanDapdan Solar Expert Posts: 313 ✭✭✭✭✭✭
    Re: small a/c or cooler

    Hey w,

    i am no expert but i can talk about my own experiences. I had a small 5000btu Ge window unit that was running of a 1000w xantrex mod inv ($60) and it was working very good. In fact the inv had no prob starting it up and running it. the only prob was battery storage. i had it cooling down a room of about 12' x 10' from 86f to 77f. the room only had one door though and it was solid fill cinder block all around (my equipment room). I had a kill a watt meter hooked up to it as well and max amp was about 5.5 at full blast. oh the other thing is that the a/c ran longer once the panels were feeding full wattage into batteries to keep the voltage up. Once the voltage stayed above cut out of inv it would last longer (upwards to 2hrs). I would say the controlling factor for my set up was the voltage drop of the batteries.

    I hope this help. if you search for my name in youtube you will find 2 videos i had posted of my system which shows the ac running with the same cheapo inverter from xantrex. If i can find the bill for the inverter i will post it. it is the same make and model that sunelec is sell refurbished at approx. $100 but the site where i bought it online it was $58 new (i bought two of them, oh yeah they were 12v, 1kw cont, 1.5kw surge)

    I hope this helps.

    Cheers

    Damani
  • wxh3wxh3 Solar Expert Posts: 70 ✭✭✭✭
    Re: small a/c or cooler

    Thanks Damani,

    One question, what was the size of your panels and battery bank? I don't know if I should do this with the current size of my panels and battery bank. I will have to get 100 to 200W of the power from the battery even in full sun even if I upgrade to 405W panels. (Note, I currently have Morningstar MPPT controller that has max 400W solar charging at 24V).
  • DapdanDapdan Solar Expert Posts: 313 ✭✭✭✭✭✭
    Re: small a/c or cooler

    hey w,

    at the time of that particular set up i had on one marine battery (about 100ah) and i had 8 KC-130tm going through a xantrex C60. as i said if i ran the a/c during the day (say anywhere between 9-3) it would run the a/c at peak out put lowest temp setting for at most 2 hrs up until the battery voltage dropped below inv cut out. the ref. to my you tube posting should have been "dapdannic". as mentioned before the only limit in my case was the size of the battery.

    IMHO if you doubled your pv input, double continous ratting inverter(or buy one of the cheap xantrex xpower 1000 (for approx. $60, 12v inverter though) you could run a small ac window unit for up to 2hr.

    Cheers
    Damani
  • System2System2 Posts: 6,290 admin
    Re: small a/c or cooler
    niel wrote: »
    try thermoelectrics. they aren't real efficient, but you'll cool a small area i'm sure with enough of them and a diversion controller.
    http://www.melcor.com/tec.html
    if you can afford the costs try one of these, http://www.melcor.com/ssair.html
    let us know if you do this how well it works.


    These coolers look similar to what's in a 12volt portable cooler or an RV fridge. If you reverse the polarity, they make heat.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: small a/c or cooler

    koco,
    yes, those are one and the same things that i'm talking about.

    dapdan,
    that avatar just made my day.:D

    adding here rather than hijack the thread that it is a cat. windsun gave us a choice many moons ago on some avatars and i chose this one due to the fact it reminded me of my cat vying for my attention on the computer desk and stepping on the keys. she also liked to watch and chase the cursor. this is more past tense now as she is older, but still does it occasionally.
  • DapdanDapdan Solar Expert Posts: 313 ✭✭✭✭✭✭
    Re: small a/c or cooler

    hey niel,

    I think hawthorne is the craziest crab ever. It took me a while to settle on an avatar but then i figured it out today. I am glad you like it as well. I must say that yours is pretty special too. i do like that cat or what ever he is and the keyboard just tops it off.


    Cheers...
    Damani
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