R22 to R438a conversionfor heatpumps

[Rodger]

We have a client with many R22 heatpumps. Heating is used about half of the year. I am looking for information on conversions that offer good heating as well as cooling. Our ambient ranges from -4ºC in winter to +35ºC in summer. Each sales company says their product is great. I am a bit wary of their claims. Has any one done any conversions with regard to maintaining the heating performance that exists with R22?

[hyperion]

Not sure if R438A is the best choice or not. See these links, they might be of help http://cr4.globalspec.com/thread/46256/R438A
http://www.gas2010.com/
http://www.idsrefrigeration.co.uk/isceon.php

[chilled444]

We have a client with many R22 heatpumps. Heating is used about half of the year. I am looking for information on conversions that offer good heating as well as cooling. Our ambient ranges from -4ºC in winter to +35ºC in summer. Each sales company says their product is great. I am a bit wary of their claims. Has any one done any conversions with regard to maintaining the heating performance that exists with R22?
R417a works brilliantly in all applications used by me up to 60kg