The water coming to the house will be a few degrees colder or warmer than when coming straight from the well pump, but this will let you use a smaller well pump and save the most energy. All the water goes through the heat pump before going to the house, so the demand needed for the house doesn't add to the amount the heat pump needs. In this example we can supply the heat pump and the house with a 15 GPM pump. In the example above the well pump needs to be able to supply 20 GPM, as the heat pump needs 15 GPM and the house needs an additional 5 GPM. This two pump system allows the heat pump to work at 20 PSI and use the smallest and most efficient pump, while the extra pump comes on to boost the pressure when the house needs water. The heat pump could run for many hours per day while the little 1/2HP will be easing along at a 1/3HP load. The house will only use water maybe 30 minutes per day, which is the only time both pump will be running. So both pumps will run when the house needs water, but the little well pump will be running by itself when only the heat pump is being used. The jet pump will pick up the 20 PSI delivered by the well pump and boost the pressure to 50 PSI for the house. When the house needs water an additional 1/2HP jet pump can draw from the same line as the heat pump. This would be the smallest pump using the least amount of energy possible for the Geo system. And when restricted with a CSV to supply the 8 GPM heat pump zone that pump will only be drawing about 1/3HP load. A Grundfos 16S05-5 is a 1/2HP that can deliver 20 GPM at 20 PSI from a depth of 24' using a CSV set at 20 PSI and a 10/30 pressure switch setting. Also using a submersible with a good drop in horsepower at low flow rates will help with efficiency. Using the smallest pump that will deliver the flow required is the most efficient system. The house requires about 5 GPM at 50 PSI. The Geo system requires 8-15 GPM at 20 PSI. A customer has a 45' deep well with a water level at 15'.