Document Type

Closed Project

Publication Date

Spring 2012


Tugrul Daim

Course Title

Decision Making

Course Number

ETM 530/630


Renewable energy sources, Heat pumps -- Technological innovations, Heat pumps -- Evaluation, Barriers to entry (Industrial organization), Energy Trust of Oregon


As time goes by, the idea of having unlimited energy resources becomes less and less feasible. The population of our world and the rate of consumption of resources increase each year. The future has us looking at alternative energy sources that will drive the need for better methods of extraction of natural energy’s like wind, water, solar, geothermal heat, and other various types of natural resources. There is a need to focus on developing more energy efficiency of current products to lessen the demand on current energy sources. Primarily powered by electricity, one of the areas to focus on energy efficiency is the heat pump water heater (HPWH). In the Northwest states (Washington, Montana, Oregon, Idaho) about sixty to sixty five percent of households use electricity as the primary source of power. Heating water can consume anywhere from fifteen to twenty five percent of the home total energy consumption. The engineering behind the HPWH doesn’t generate its own heat while running. Rather the HPWH uses the ambient air surrounding the water heater and functions in revers of a refrigeration or air conditioning system. According to Energy star:

“HPWH takes the heat from surrounding air and transfers it to water in an enclosed tank. A low-pressure liquid refrigerant is vaporized in the heat pump's evaporator and passed into the compressor. As the pressure of the refrigerant increases, so does its temperature. The heated refrigerant runs through a condenser coil within the storage tank, transferring heat to the water stored there. As the refrigerant delivers its heat to the water, it cools and condenses, and then passes through an expansion valve where the pressure is reduced and the cycle starts over.”

Research Question: Why has the HPWH had such a slow or low adoption rate in society?

Research Objective: There are factors and sub factors that are affecting the adoption of the Heat Pump Water Heater. The factors we have identified are economic, politic, social, technical and environmental. The sub-factors (elements) will be constructed at a later time and into the HDM model to find the causes that affect the adoption of heat pump water heater.


This project is only available to students, staff, and faculty of Portland State University

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