Question for those in the know!

Lobo Registered Users Posts: 18
I have a dehumidifier that I need to run 24 hours a day constantly.  It is a 115V unit with a rated 6.9amp draw and 750 watts.  What would be needed for operation of this unit while using 12 volt panels.  Second, battery recommendations?  Thank you in advance for any help.


  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    750 watts X 24 hours = 18 kilowatthours per day energy consumption. 

    Typically we recommend that your daily load should equal 1/4 of a battery's capacity.  Thus you would want a 72 kwh battery.  A 12 volt battery bank with 72 kwh capacity is a 6000 amphour battery bank.

    To charge it with solar you would need about 8 large charge controllers, with each controller having about 1250 watts of solar panels.

    To build a 6000 amphour battery bank at 12 volts will require multiple parallel batteries, which is a poor design... you would be better off with a single string of 1500 amphour batteries configured at 48 volts.  With a 48 volt battery you would only need 2 large charge controllers, each with 5000 watts of solar panels.

    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Lobo
    Lobo Registered Users Posts: 18
    Thank you!
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭

    Basically, you need a different way to humidify the air. Humidifiers have a heating element which uses a good bit of electric.

    Perhaps a mister... or evaporative cooler, these use a fan and membrane or just a fan and a fine mist. a 8-40 watt fan is the major energy use...

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former, 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Aguarancher
    Aguarancher Solar Expert Posts: 315 ✭✭✭
    I think he's trying to remove humidity.
  • petertearai
    petertearai Solar Expert Posts: 471 ✭✭✭✭
    Hi what type of dehumidifier do you have . That seems to use a lot of energy. 
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,713 ✭✭✭✭✭✭
    You would use a mini-split heat pump to dehumidify !
    "we go where power lines don't" Sierra Nevada mountain area
    E-mail [email protected]