Capillary is the throttling element for room air conditioners, with the advantages
of simple operation and reliability, but with the ultimate disadvantage that the
flow can't be adjusted automatically in accordance with the load. It can only
economically operate under the unique set condition, while the actual operation
condition is always different from the set operation condition. Hence, there's
decreased refrigerating capacity and energy efficiency ratio.

When the expansion valve is used as the throttling element, the average refrigerating
capacity can be increased above 15%, and the average energy efficiency ratio
can be increased above 13%.

Features:
1) Bidirectional operation: cooling and heating
2) Airtight performance: annual leakage below 3g
3) Compact size, low material consumption, low cost
4) Easy to install, energy saving