They may be set up indoors or outdoor but does call for use of a 110v outlet to run the filtration program and compressor for cooling the water. The user reclines from the tub for total immersion. Innovative Filtration and Ventilation Outfitted with a complicated filtration and ozone purification procedure, https://www.google.com.af/url?q=https://www.renutherapy.com/products/cold-stoic-3-0