RESIDENTIAL HEAT PUMPS

Residential Heat Pumps



Residential Heat Pumps

Introduction

The heat pump is a machine that can transfer heat from a body at lower temperature to a body at a higher temperature, using energy, usually electrical form.Common examples of machines of this type are:

refrigerators;

air conditioners;

heat pump gas compression;

heat pump Phase change;

Heat pump thermoelectric effect;

exchange geothermal heat pump;

Vortex, also known as tube.

Note that, in the field of air conditioning, heat pump is the term specifically refers to a reversible air conditioner valve, which changes the flow direction of the refrigerant and thus allows both to make is to extract heat from a room of a building.

Operation

Residential Heat pumps are powered by different physical principles, but are classified according to their application (transmission of heat, heat source, heat sink or freezer machine).

It presents an intuitive explanation of how heats pump. You imagine 100 units of thermal energy within a soccer ball; the latter is then compressed to the size of a ping pong ball: At this point it contains the same 100 units, but the average thermal energy per unit volume is much higher. In other words, the air temperature inside the ball is increased. The walls of the ball will heat up and then the heat begins to move out faster. To bring this heat to another place, one can imagine moving the ball in a cold area, where it gradually will adjust its temperature to match the ambient temperature: in this process it is assumed that 50 units of heat transfer. After the ball has cooled, it can bring in the initial area and let it expand. Since he has lost a lot of heat, when he returns to the size of a football, its temperature is too low and then begins to absorb heat and cool the surrounding air.

The compressor of a heat pump just creates the pressure difference that allows the cycle to repeat itself (similar to the ball that expands and contracts): it pumps the refrigerant through the evaporator, where it just evaporates, absorbing heat at low pressure, then compresses it and pushes it into the condenser where it condenses at high pressure by releasing the previously absorbed heat. The refrigerant changes state within the two radiators: the evaporator is changed from liquid to gas; the condenser is changed from gas to liquid. (Chiasson, 1999)

Efficiency

When comparing the performance of a heat pump, it is best to avoid the term "efficiency", since it has different meanings. The yield of a heat pump is measured by the coefficient of performance, COP, the ratio between energy output (at the source of interest) and energy consumed (usually electricity), usually given in technical physics as the coefficient of effectiveness. A value of the COP, for example, 3 indicates that for every kWh of electricity consumed, the heat pump will make 3 kWh of heat.

When used for heating with a mild climate, a typical heat pump has a COP of 3 to 4 (average 10 ° C reaches ...