Micro-District Concept, an Emerging Trend in Heat Pump in United States

Heat pumps are energy efficient devices that transfer heat from a location with little air circulation to the warmer regions of a building. They are usually installed as part of a complete HVAC system, but may also be used independently. They can provide a comfortable climate for living, while at the same time lowering your monthly utility bill.

Air-to-air heat pump systems, the most popular form in the U.S., utilize air to transfer heat from inside a building to the outside air using a heat exchanger. Moreover, the state of Massachusetts has recently witnessed increasing adoption of geothermal micro-district concept that aims to slash fossil fuel use while providing an economic transition for gas utilities and their workers,

The power source to a heat pump is rarely used directly, but is instead used indirectly by taking the power from the mains gas supply to the unit, and using it as an energy source to start the motor. As the heat pump extracts energy, it uses the stored energy to heat the indoor air. The energy source is not limited to heat energy, but may also be used for convection, ventilation and for external air conditioning.Air-to-water heat pumps utilize the principle of drawing heat from the outside air and transferring this to the indoor water system. They are particularly suitable for heating small buildings, such as sheds and storage facilities. 

Water heating systems work well in these situations because they do not take up much space and do not require a great amount of electricity. This cooling method employs different principles to the common chillers used in industrial and commercial settings. A heat pump uses a series of copper pipes, called heat exchangers, to draw hot air from outside. Water is then pumped into the pipes and pushed through a heat exchange, where the temperature rises because of the heat exchange's evaporation process. The end result is cooler, warmer air entering the house at an average rate, rather than the constant rise and fall of the room temperature.

Heat pumps have been used in various types of buildings, from commercial buildings to domestic residences. Commercial heat pumps are often small, such as those used in supermarkets and mini-malls. These are known as mini air conditioners. Commercial buildings can benefit from central heating and ventilation combined with the installation of a mini air conditioner that draws heat from the building's air conditioning system. These are also used to lower temperature in the winter months, which makes them popular for homes.