Absorption refrigerators are efficient users of electrical power, which powers the control unit, and propane (for cooling), but are slow to cool down from startup. Adding fans, both inside and outside, will improve efficiency and uniform cooling. Since RVs are frequently used where electricity is limited to batteries, household type (using a compressor and Freon) refrigerators are impractical. If an owner has a large enough coach with a large (six or eight 6 volt batteries), and is willing to recharge this battery bank frequently, then a residential type is preferred.