pinched refrigerant line

[John Dirks Jr]

In the picture you'll see the high side line squashed. It still had some flow capability but I'm sure its reduced.

I had no problem with standard wording in writing this up. However, I would like to know from technical standpoint, what exactly will happen in this case which could lead to problems?

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[Marc]

Liquid refrigerant expands into a gaseous state when the pressure is reduced to the flash point of the liquid. This happens by design at the expansion valve, capillary tube or whatever restriction device is installed. With this squashed liquid line, some pressure drop likely occurs across it. If the pressure drop is sufficient, some of the liquid may flash into a gas, which reduces the amount of liquid refrigerant available to the restriction device and the overall tonnage available to cool the house.

If flashing occurs at the squash point, you'll be able to feel the line become cold at the squash point. In more severe conditions, ice will build up. The squash might also increase the possibility of liquid flashing at some other point between the squash point and the restriction device with the same detrimental effects.

It's more likely to flash when ambient temperatures are higher, which means the detrimental effect of the squash is highest on days when cooling is most needed.

Marc

[rkenney]

• Evaporator starvation
• Evaporator icing
• Low/no airflow (blower)
• Insufficient cooling
• High compressor pressures (discharge)
• Low suction pressure
• Ultimately Compressor failure

Same end result as a low refrigerant charge.