Are Two Dehumidifiers Better Than One?

Andrew Leahey

You may erroneously believe that two dehumidifiers will be better than one with regards to energy efficiency and overall cost. While two units may be less expensive than one larger unit when considering upfront cost alone, the cost of running two smaller units will be significantly more expensive in energy costs over time.

Upfront Cost

Oftentimes smaller dehumidifiers are less expensive than their larger counterparts, which may lead you to believe you can simply purchase a unit rated for a smaller room than you intend to use the dehumidifier in and add additional units as you can afford them. This assumption is incorrect, as an undersized dehumidifier will consume considerably more energy than a properly-rated model. Additionally, any costs saved by purchasing smaller units will quickly be eaten up by running two units simultaneously.

Larger Is Better

The larger the dehumidifier, the better off you will be over the long run in regards to energy consumption. A unit rated for slightly larger than the room you are trying to dehumidify will rapidly remove humidity from the air and then cycle off until the humidity reaches a set threshold, which saves you money in electricity and also reduces noise pollution in your home from a constantly running dehumidifier.


Extreme conditions can make a unit rated for the room you are intending to use it in still remain undersized. If you are intending to dehumidify an exceedingly damp or wet area, such as a basement that frequently floods or a crawlspace with standing water, upgrade to the next higher model than the space would call for. For example, if the unit you are intending to purchase is rated for a 1,000 square foot room and your room is that size but extremely humid, purchase the model that is rated for 1,500 square feet or more.

Proper Placement

Proper placement of your dehumidifier is key to running it as efficiently as possible. Your dehumidifier should be placed away from walls and obstructions if it has an output grill located on the back or side of the unit. If the unit discharges air from the top, you can safely place the unit against a wall, but do not place anything on top of the unit obstructing airflow.