Potential impact of energy cost optimization for electrical floor heating systems under day ahead spot electricity prices and user set comfort levelsUuemaa, Madis; Uleksin, Taaniel; Tammoja, HeikiWSEAS transactions on power systems2017 / art. 14, p. 124-133 : illhttp://www.wseas.org/multimedia/journals/power/2017/a285816-079.pdf