Final answer:
To ensure proper drainage for a heat pump system, the primary and secondary evaporator drain lines should be sloped downward away from the unit, should not be connected to a common drain pipe, must include a P-trap, and a condensate pump may be necessary if gravity drainage is not possible.
Step-by-step explanation:
Guidelines for Running Primary and Secondary Evaporator Drain Lines
When configuring the drain lines for evaporator coils in a heat pump system, it is important to follow several key practices to ensure proper operation and safety. First and foremost, both the primary and secondary evaporator drain lines should be sloped downward away from the unit. This ensures that condensate can drain effectively by gravity and does not pool in or around the unit, which could lead to water damage or system malfunction.
Next, it is generally not recommended to connect both the primary and secondary evaporator drain lines to a common drain pipe; this could result in cross-contamination or backflow issues if one of the drains becomes clogged. To prevent sewer gases from entering the indoor environment, it is critical to use a P-trap on both the primary and secondary evaporator drain lines. This is because the P-trap will hold a small amount of water, creating a seal that blocks gases from coming back through the drain lines into the space.
Lastly, in situations where gravity drainage is not possible, it may be necessary to install a condensate pump on the primary evaporator drain line. The pump will actively move the condensate to a proper disposal location, ensuring the system continues to operate without issues related to water drainage.