Requirements

In any geothermal project, the first step of designing a system is to determine the amount of heat required for the building. This is done by using a traditional heat load analysis software program such as the CSA F280 program for Canada, or an implementation of the ASHRAE Manual J Residential Building Load Standard. This program will determine the amount of heating and cooling needed for the structure at the design temperature for your location.

With this information you can choose the heatpump model required to supply the energy needs of the home. Heating and cooling loads are only equal if the area of the country in question falls within a specific lattitude. Lattitudes in the Northern hemisphere will have a predominantly heating load, while southern lattitudes are predominantly cooling as one moves towards the equator. For example, if a home required 50,000 BTUs/hr. in New York to satisfy the heating load it may only require 25,000 BTUs/hr. in the cooling mode, thus the homeowner needs to select heating or cooling as his priority for the heat pump system.

Since most people select a geothermal heatpump to save energy and reduce their heating costs, it makes sense to select a heatpump which will meet the entire heating load of the home. In this way a home owner can maximize energy savings.

     Once the load of the building is known and the heatpump capacity is selected, the type of earth connection to be used must be determined. If the home is located in a rural area and a well is already needed to supply water to the home the cheapest technique for supplying energy to the heat pump is to use a common water well (1) . A return well is usually the best technique for returning the water back to the earth. In this manner no water is wasted, and the system is ecologically sound. In areas where sufficient water cannot be obtained, then the next best option is a horizontal ground loop if 1/4 to 1/2 an acre of land space is available for this use (2) . The ground heat collector plastic piping system is buried 6 feet under ground and thus the land can still be used for other purposes once the collector is in place. If the land space is not available then the final option (although most costly) is to install a vertical borehole system, where the ground heat collector piping system is placed in veritcally drilled boreholes, where it functions identically to the horizontal version (3) . A vertical borehole system can always be used, on any lot since the space in between the boreholes is only 15 or 20 feet and they can be placed in various patterns.
      The final area of concern would be how the heat/cooling is to be distributed throughout the home. Either forced air or infloor heating are the 2 main types of heat distribution. Forced air system provides heating and cooling through the same distribution duct network, thus minimizing capital costs, while an in-floor heating system generally provides greater comfort but requires a duct system for cooling. Capital cost for the combination distribution system are, of course, higher.
       The brochure above discribes the capacities of the heat pumps Maritime Geothermal manufactures and the general requirements for water, land usage, and air flow capabilities of each.