3-5 Years Click to see full answer. Keeping this in view, do whole house dehumidifiers really work?Yes, that’s the short answer. Whole house dehumidifiers work really well for what they are meant to accomplish. They will help reduce the percentage of humidity in the air in your home.Similarly, is it OK to leave a dehumidifier on all day? Overusing a dehumidifier and switching rooms. If the dehumidifier is allowed to run all day every day in one room this could lead to levels of moisture that are too low – which in turn could cause problems for you. Including dry itchy eyes and respiratory problems and dry cracked skin. how long should a dehumidifier last? three to five years How much does it cost to have a whole house dehumidifier installed?It costs $1,300 to $2,800 to install a dehumidifier. Basement models average between $1,300 and $1,800, while crawl space ones are $1,500 to $2,000. Whole-house versions could be as low as $1,500 and as high as $2,800.