Before purchasing a dehumidifier, it is important to know how much electricity it draws. To determine how much power your dehumidifier consumes, you must first determine its Watts (W). The information on power draws is often found in the product description or online. You can also multiply the voltage and amperage by 1,000 to get the kilowatts (kW) it draws. Once you have those two numbers, multiply them together and you'll know how much electricity it consumes every hour.