Why are we using ""nozzles"?

**skr0oface** · 12-05-2007, 10:49 PM

Hello All, Just have a question on my mind and would really appreciate someone to shed light on. I just started in the supermarket side [from residential] 2 months ago. We are doing grocery store reno's, and I am becoming great at brazing and doing kick plates =]. Anyhow We have 3 walk ins with the evaps to install tomorow. The TXV for each came seperatley. We opened up one of the evaps and I was shown these "orifices" as someone called them, and to make sure I install the correct one for the correct refrigerant. I looked on the package and they were labeled as nozzles. I didnt get as far as seeing if their was any literature on them.

Long story short I was curious why would the system need an orifice if its going to employ a TXV to meter refrigerant? And if it's job isnt to meter refrigerant whats the purpose of it?

**powell** · 12-05-2007, 11:04 PM

Originally Posted by skr0oface

Long story short I was curious why would the system need an orifice if its going to employ a TXV to meter refrigerant? And if it's job isnt to meter refrigerant whats the purpose of it?

You are correct, the nozzle is not a metering device. It's job is to distribute the refrigerant equally and evenly throughout the distributor tubes, after it's metered by the TXV, into the evap. This prevents the refrigerant from shooting through the path of least resistance. Which will cause the bottom rows of the evap to remove heat more efficiently than the top . This sometimes causes the bottom rows to ice up.