Central heating. According to the website of the people's government of Huanghua Economic Development Zone, Huanghua Economic Development Zone keeps out the cold through central heating. Hebei Huanghua Economic Development Zone is located in the south of Huanghua City, a provincial economic and technological development zone approved by Hebei provincial government 1992. In July 2006, the Development Zone was approved by the National Development and Reform Commission, with a standard planned area of 6 square kilometers.