CRD Ground Loop & Heat Pump Configuration 2

Question 1

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

Accepted Answer

More heat exchange surface area per linear trench foot

Answer

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

Question 2

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

Accepted Answer

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

Answer

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.

Question 3

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

Accepted Answer

SCW draws groundwater up and returns it to the same well

Answer

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

Question 4

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

Accepted Answer

Reversing valve position

Answer

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

Question 5

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

Accepted Answer

20–50 BTU/hr·ft

Answer

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

(CRD) Certified Residential Geothermal Designer Practice Test

(CRD) Certified Residential Geothermal Designer Practice Test

CRD Ground Loop & Heat Pump Configuration 2