They are air, calcium chloride brine, sodium chloride brine, alcohol, and similar nonfreezing solutions. The purpose of Class 2 refrigerants is to receive a reduction of temperature from Class 1 refrigerants and convey this lower temperature to the area to be air-conditioned.
Elections for the United States Senate will be held on November 8, 2016, with 34 of the 100 seats in the Senate being contested in regular elections whose winners will serve six-year terms from January 3, 2017 until January 3, 2023.
Every two years, one-third of the Senate is elected, so your state may or may not have a Senate contest in a given general election year, which is a year in which candidates are elected in most constituencies. General elections are held in even-numbered years (1994, 1996, 1998, and so forth).