To Thesingingbard,
2 possible reasons.
Either the copper pipe is slightly dented. Causing gas flow to be not smooth.
Iceing happens after a few hours of usage. And leads to water leak.
Or your trunking is undersized, cause the insulation to be pressed against other piping inside the trunking.
How many sets of piping r inside the trunking?
To Tinyuan.
The Panasonic sys 2 price is attractive.
Arcoflex and Armaflex r different brands of Insulation.
1/2 is thicker then 3/8.
If your piping is inside trunking, 3/8 is enough.
U can also read up more on my blog.
Http://www.airconguru.blogspot.com