View Full Version : Cap tube vs AEV on AC units

28-08-2004, 08:24 AM
Speaking of automatic ex valves how many of you have used constant-pressure expansion valves in place of or in parallel with capillary tubes in air conditioning applications. They work quite well because at low-load conditions, the AXV maintains a higher suction pressure, thus preventing coil freeze-up. Additionally, at higher load conditions, the AXV maintains a lower suction pressure, thus reducing power consumption and protecting the compressor against overload. :cool:

30-08-2004, 06:25 AM
Additional considerations would have to made like whether to go critically charged or not, whether to use an accumulator and how large. These might be common considerations just that in the case of AEV's they would surely be more important.

An automtic exp Valve with a bypass or bleeder one would need the above requirements , however, one doesn't have to use this type. Still the fact remains that since the AXV maintains a constant suction pressure, this will result in a more efficient compressor operation than the cap tube; this allows us to use a lower-capacity compressor which gives us a better COP.:cool:

31-08-2004, 12:58 AM
You may be incorrect.
OH, I forgot to add [using the original condenser] :(