What is the difference between the way a secondary refrigerant ...

[frankwu]

What is the difference between the way a secondary refrigerant absorbs heat and the way a primary, direct expansion refrigerant absorbs heat?
 
  What will be an ideal response?

Question 2

How is heat transferred in a heat pump ground loop?
 
  What will be an ideal response?

[nmyers]

Answer to Question 1

In a direct expansion system, the primary refrigerant evaporates and expands, absorbing both sensible and latent heat. In contrast, a secondary refrigerant does not evaporate and therefore only absorbs sensible heat, which makes the temperature difference and surface area requirements greater than those needed for a direct expansion system.

Answer to Question 2

The water acts like a secondary refrigerant, absorbing heat from the soil and transferring it to the refrigerant in the heat pump.

[frankwu]

Excellent

[momolu]

Thanks for the timely response, appreciate it