Replies

1. GBA Editor
   Martin Holladay | Oct 16, 2016 05:46am | #1

   Nate,
   I welcome GBA readers to respond to your question. There are some air-source heat pumps successfully using CO2 as a refrigerant; for more information, see these articles:

   A Heat Pump Using Carbon Dioxide as the Refrigerant

   The Loophole and the Ozone Hole

2. 
   Dana1 | Oct 16, 2016 10:43am | #2

   The agreement is for staged reductions on a timeline, a timeline that varies by country:

   "Developed countries must reduce their use of HFCs by 10 percent by 2019 from 2011-2013 levels, and then by 85 percent by 2036.

   A second group of developing countries, including China and African nations, are committed to launching the transition in 2024.

   A reduction of 10 percent compared with 2020-2022 levels should be achieved by 2029, to be extended to 80 percent by 2045.

   A third group of developing countries, which include India, Pakistan, Iran, Iraq and Arab Gulf states, must begin the process in 2028 and reduce emissions by 10 percent by 2032 from 2024-2026 levels, and then by 85 percent by 2047."

   http://www.aljazeera.com/news/2016/10/kigali-deal-agreement-reached-phase-hfcs-161015075725587.html

   If you're putting off heat pump appliances purchases until after the phase out to avoid being stuck with obsolete equipment that won't be serviceable, don't- you'll be waiting a very long time. But if you want be among the first to use equpment with HFO1234yf (or other HFO1234 variant) refrigerant equipment you probably won't have to wait too long for at least some equipment to show up. HFCs have been banned in Europe for automotive AC applications for a few years now, and there's on the order of 10 million cars on the road that use HFO1234yf it right now. (HFC134a is still the market leader for car AC in the US though.)

3. 
   Jon_R | Oct 16, 2016 12:02pm | #3

   Probably R290 (propane) and similar HCs will be most popular.