Thursday 19 January 2012

How a Heat Pump Works

Heat pumps are an effective and efficient way to both warm up and cool down substances and spaces. Heat pumps use a fluid, called a refrigerant, that circulates within a tube to transmit heat from one location to another. A heat pump can be used to cool down a room by moving heat from it to the outside. A heat pump can also be used to heat a room by transferring heat from outside in.

There are a number of types of heat pumps, and as soon as you figure out how they work, in general, it becomes possible to comprehend how every one of the various types works in its specific set of conditions. Heat pumps rely on two physical properties of liquids, condensation and evaporation to accomplish the heat transfer. When a liquid changes to the gaseous state, it rapidly absorbs heat from the environment. On the other hand, when a gas condenses and becomes a liquid it gives up its heat to its surroundings.
Now think about how the heat pump warms a room. The pump first causes the internal fluid to evaporate, and then travel through a section of the circular tube placed in a space meant to lose heat. The gaseous refrigerant readily absorbs heat from the surrounding environment and then continues to circulate in the tube. Next it travels to the compressor, which compresses the gas making it to heat up greatly. Now the hot gas travels to the condenser, which is situated in the part of the circular tube situated in the room to be heated. The gas is made to condense and while doing so it gives up a lot of heat to the surrounding vacinity. The same condenser, which is located outside. The gas reverts to the liquid state and gives up its heat to the outside. The refrigerant when a gas can so readily absorb heat that it can absorb warmth from air that is cooled to 0 degrees Celsius. as a result heat pumps can, in fact, heat abodes even in the dead of winter.Naturally, as the outside temperature drops, the efficiency of the pump decreases.

However, newer pumps can continue to work with 60% efficiency, even when the temperature drops to-17 degrees Celsius. The efficiency of a heat pump is described in terms of its Coefficient of Performance (COP). The COP is the ratio between the amount of energy used to make the pump work and the extent of heat change in the area being heated or cooled. While an electrical heater normally has a COP of 1, heat pumps usually have COPs which can range as high as 7-8 in ideal conditions. This means that in most circumstances, heat pumps are more effective at heating and cooling than electrically powered heating and cooling units. This is the reason they are so often used today in the HVAC industry.

No comments:

Post a Comment