Ground Loop & Heat Pump Configuration Flashcards

What is the primary reason a designer would choose a slinky horizontal ground loop over a straight horizontal loop?

Answer: More heat exchange surface area per linear trench foot

Slinky coils pack more pipe into each trench foot, increasing heat exchange area when land area is limited.

In a series ground loop circuit, how does flow rate compare to a parallel circuit of the same total pipe length?

Answer: Series uses lower flow rate because all fluid travels the same path

In a series circuit, one flow stream passes through all pipes sequentially, so the required flow rate is lower than a parallel circuit handling the same total heat transfer.

A standing column well (SCW) differs from a closed-loop vertical bore primarily because:

Answer: SCW draws groundwater up and returns it to the same well

A standing column well circulates open-loop groundwater within a single deep well, bleed-and-return, rather than a sealed fluid loop.

Which parameter most directly determines whether a heat pump operates in heating or cooling mode?

Answer: Reversing valve position

The reversing valve switches refrigerant flow direction, determining which coil acts as condenser or evaporator and thus the operating mode.

For a vertical closed-loop system in saturated soil, what is the typical design range for heat extraction per bore foot?

Answer: 20–50 BTU/hr·ft

Saturated soils typically yield 20–50 BTU/hr per bore foot, depending on soil conductivity and system run time.

What is the purpose of a pressure/temperature (P/T) port on a ground loop header?

Answer: To measure entering and leaving water conditions without draining the system

P/T ports allow technicians to insert probes and read pressure and temperature data for diagnostics without breaking the sealed loop.

Which heat pump refrigerant cycle component is responsible for raising the refrigerant pressure before it enters the condenser?

Answer: Compressor

The compressor increases refrigerant pressure and temperature, enabling heat rejection at the condenser.