Low Cost of Operation is achieved only by understanding the nature of the energy requirements, reducing the need as much as possible, developing the system strategy, selecting the most appropriate components, and understanding not only the steady state efficiencies, but also the part-load and transient system efficiency.

Geothermal Heat Pumps and Solar Thermal Strategies have proven to be appropriate technologies for most heating, cooling and water heating applications.

The experience at Phoenix Energy Supply goes back to the 1970's when the founder of the company was awarded a National Science Foundation Grant to research Solar Assisted Heat Pumps at Syracuse University.

Phoenix Energy Supply has developed Operating Cost Estimating Tools based on industry accepted methodology as well as the need to express the results in a manner that is easily understood and effectively communicated.

The "Screenshot" at the right illustrates the main interface of the software which provides immediate feedback to changing inputs.

At the heart of estimating operating costs is quantifying the heating and cooling loads, which for Residential applications the ACCA Manual "J" method is appropriate. After determining the peak loads for both heating and cooling a load line is constructed to determine the heating and cooling requirements as related to outdoor temperatures other then the "Design Temperature".

The "Bin-Data" Method is then utilized to evaluate the required energy over the expected amount of time at a given outdoor temperature (actually 5 degree bins). The chart at the right illustrates the bin distribution - the number of hours in a average year - which occur at each of the 5 degree bins. This data is for Syracuse, New York. Data is available for a great variety of cities throughout the world.

After a heat pump selection is made it is now possible to illustrate the heat pump capacity (BTU per hour Output) versus the Load (BTU's per hour required). The outdoor temperature where the heat pump equals the load is called "The Thermal Balance Point"", below which additional heat will be required, typically electric resistance heat is cycled on and off as required to maintain the required indoor temperature. It should be noted that the heat pump is still supplying most of the heat required and may run continuously during these excessively cold periods.

The red area on the chart to the right illustrates the relatively small amount of electric resistance energy that is required and thus the best economic choice. Equipment sizing is to select according to the specific location and a size that has a Thermal Balance Point between -5 F and 10 F (at least for Syracuse, NY). The incremental investment required to save a small amount of electric resistance operating cost is not necessarily a good investment.

The table and chart to the left illustrate how this properly sized geothermal heat pump will compare to other sources of heating energy. The chart also illustrates the Carbon Footprint associated with heating. In New York State the average kilowatt-hour of electricity is generated by producing 0.76 pounds of carbon dioxide. However, by sourcing your electicity from either onsite or off site cleanly generated electricity it is within our reach to have Zero Carbon Emissions associated with staying warm and comfortable.