ClimateMaster’s Clima-Dry option uses the water side of the system to do re-heat after the evaporator coil to dehumidify the space on demand. If there is no heating or cooling call, but the connected humidistat calls for dehumidification, an internal circulator pump and mixing valve directs ground loop water to a coil after the evaporator. The mixing valve modulates to achieve an output air temp of 72 degrees.
The HWG will make more hot water in the heating mode because the annual run time is much higher, and the system head pressure is higher in the heating mode.
The efficiency of the open loop system is affected by the water table. We are using electricity to lift water from the water level in the well up to the home, and then we are pressurizing a tank to 50 lbs which is equal to another 115 ft. In many cases, the closed loop system with 32 degree entering water temperature is more efficient than the open loop system that enjoys 52 degree water at all times.
Typically, the average entering water temperature for heating will be a bit higher from a vertical closed loop system. There is less surface area of pipe, but the deep earth temperature is around 52, where the undisturbed ground temperature at 5’ deep is only 47 degrees. Also, in the vertical we are typically in water saturated rock instead of damp soil. However, the difference in operating cost is not enough to offset a larger installation cost.
In nature, heat energy moves from a warmer place to a colder place. Therefore in the heating mode, the water in the pipes of a closed-loop heat exchanger must be colder than the ground around it so that heat energy will flow through the walls of the pipe. How much colder it needs to be depends upon the amount of surface area of pipe we bury, and the run-time of the unit. If the unit is running on low stage for half of the hour, then the water can be warmer because we don’t need as many BTU’s per hour to move compared to constant run of high stage.
There is an economic balance point for the size of our ground loop. If we decide to increase the ground loop size in order to keep the water temperatures warmer, we must be sure that we will save enough additional dollars to pay the higher first cost.
Installing one ground loop will always be more efficient. If either unit runs longer due to varied loads throughout the home has access to all of the ground contact. During the winter, a first floor unit will address up to 30% of the heating load upstairs, and vice versa in the summer.
Yes, the dedicated tank provides a place to put the heat whenever the unit is running. If the homeowners wash dishes, clothes, and give the kids a bath in the evening, the elements or burners in the water heater will replace those BTU’s in a couple of hours, and then the Geo unit will run all night with nowhere to put the heat.