I'm inexperienced in A/C systems. I have a new Si and hear a sound cycling off and on when running the A/C. Almost sounds like something bleeding air off, possibly a relief valve? I'm sure it's normal, but more of an annoyance. Happens every 15-30 seconds and lasts a few seconds each time. Anyone familiar with this sound? Anyway to quiet the sound? Insulation? Thanks...

 

Apparently it's the expansion valve making this hissing sound. Anyone know where it's located and if it's easily accessible. Wanted to see if there's a way to insulate it or deaden the sound.