They are self-contained systems. The heat pump unit is housed entirely within the house or building and is connected via pipes to the outside buried ground loop. Advantages Economical operation. Even in sub-freezing temperatures, geothermal heat pumps produce supply air 20 F warmer than conventional heat pumps. Last longer than conventional heat pumps.
Efficiencies are good.
EER ratings of 13.0 to 20.0 and COP ratings of 3.5 to 5.0 are common. Disadvantages High initial capital costs, from what I ve heard so far. Duct a passive outside air intake with a damper into the fan coil return before the filter for whole house make up air. Manually set the damper to provide approximately 110cfm make up air when the fan coil unit is on high. Submit catalog cuts.