Tumble dryers and drying cabinets have to a large extent replaced the traditional way of drying clothes outdoors. They are faster, more convenient, require less space and can be operated regardless of weather conditions. This replacement has significantly increased residential energy consumption, due to the fact that tumbles dryers consume large amounts of electrical energy. In the USA 9 % of the households electric energy is consumed when drying clothes. Over 4 million tumble dryers are sold in Europe each year and 20 % of the residential electricity consumption in Sweden is used drying and washing clothes. Tumble dryers are also utilized in the industrial sector, but industrial dryers are not considered in this study.Increasing energy costs contributes to the public’s awareness and desire to cut their energy consumption. The aim of this study is to increase the energy efficiency and drastically reduce electric power use of tumble dryers.There are two main types of tumble dryers available on the market; the open cycle tumble dryer and the closed cycle tumble dryer. The open cycle tumble dryer is often attached to the ventilation system and thereby it evacuates its exhaust air. The closed cycle tumble dryer condenses the water from the air before it recirculates it.To increase the energy efficiency and reduce electric power use of tumble dryers, two separate studies were made. One on a water cooled closed cycle tumble dryer and one on a hot water heated open cycle tumble dryer. Both tumble dryers where rebuild and originated from the same tumble dryer. The tumble dryer that both studies originated from was a conventional air cooled closed cycle tumble dryer. The tumble dryer is made by Asko Cylinda AB.The results reveal that the water cooled closed cycle tumble dryer does not have greater energy efficiency than the conventional air cooled closed cycle tumble dryer. However the drying time was reduced by 37 %.The result also reveals that the hot water heated open cycle tumble dryer cuts the electric consumption by 93 % and improves the energy efficiency by 53 % compared to the conventional air cooled closed cycle tumble dryer. On the other hand the drying time increases by 9 %.