Where should an automatic purger be piped from on the condenser?

The automatic purger should be piped from the outlet drain of the condenser because this location is optimal for the effective removal of non-condensable gases that accumulate within the system. By placing the purger at the outlet drain, any gases are efficiently vented away as the refrigerant leaves the condenser, ensuring that the condenser operates efficiently and maintains proper pressure levels. This setup prevents the buildup of unwanted gases that can impair heat transfer and reduce overall system performance.

In contrast, the other locations proposed would not provide the same level of effectiveness. The highest point of the condenser might seem logical for gas removal, but it may not effectively capture the gases that are entrained with the refrigerant. A middle point could miss the non-condensables altogether as they typically rise to the top. Piping from the inlet would lead to non-condensables accumulating rather than being expelled, which is undesirable for efficient system operation.