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.
Federal elections occur every two years, on the first Tuesday after the first Monday in November. Every member of the House of Representatives and about one-third of the Senate is up for reelection in any given election year. A presidential election is held every fourth year. Federal elections are administered by state and local governments, although the specifics of how elections are conducted differ between the states.