Heat Pumps
The first law of thermodynamics is an expression of the universal law of conservation of energy. Its enunciation states that the increase in the internal energy of a thermodynamic system is equal to the amount of heat energy added to the system minus the work done by the system on the surroundings.
The principle of heat pump adheres to the first law of thermodynamics. The heat pump is invented to preserve the load such as perishable matters as food. Foods are perishable when the temperature is higher. They tend to last long when it is below temperature or in freezing point. Heat pumps like refrigerators and freezers are important for preservation of important things such as food.
What Is Then A Heat Pump?
A heat pump is a system designed for the purpose of heating and cooling. Its actions are essentially the same for either process. Instead of creating heat, the heat pump transfers heat from one place to another. As in the case of the food, the refrigerator absorbs heat from it. The absence of heat from the food makes it less vulnerable to bacteria or spoilage.
The heat pump technology is what we refer to some common appliances such as refrigerators, freezers, air-conditioners, chillers and drinking fountains.
The second law of thermodynamics states that heat cannot flow from a colder area to a hotter area; an impetus should be done to achieve this.
The heat pump works by moving the refrigerant to a cycle in which it can absorb heat from a load or can exhaust the heat. The refrigeration cycle is the basic principle in HVAC system. HVAC technicians adhere and rely to the principle of refrigeration when troubleshooting or repairing heat pumps.
The refrigerant or commonly called freon is an important substance of heat pumps. It is normally in a liquid state when it is inside the freon tank or in an closed pipe. It evaporates into the air when released from a freon tank. When it is inside the heat pump, it is not advisable to open the valve as the refrigerant may evaporate through the atmosphere. Leaking the pipe of the heat pumps may cause the freon to evaporate all of the its substance into the system. Heat pumps can not work effectively without the freon.
Refrigerant is the substance being pumped by a compressor to pressurize it and change it into a high-pressured gaseous state. A refrigerant in liquid form is the reason why a heat pump may cool an area or may freeze an object. Refrigerant’s temperature in liquid state is almost or is in freezing point that when it is sprayed to an object, the object gets frozen.
The energy efficiency is attributable to the compressor which is the heart of the system. Every part of the heat pumps such as the evaporating coils, condensing coils, expansion valves, refrigerant and lubricant is important in the application of heat transfer.
The most common heat pumps are the refrigerators and air-conditioning systems. Refrigerators are used for storage of food. The air-conditioning systems are used for comfort during climate change and for undesired temperature. The popular type of air-conditioning systems are the window-type system and the split-type free-blow packaged air-conditioner (the air-handling or indoor unit is separate from condenser or outdoor unit). This is also called as ductless heat pump for it eliminates the need of ducts and dampers.
Some of the popular brands of heat pumps are Carrier heat pumps and Trane heat pumps.
These can range from the simple window-type to the packaged-type. Heat pump’s cooling or heating capacity depends on the size of the unit, the load and the size of the area where they will be installed.
Normally, heat pumps use thermostat to set the temperature and to regulate the overuse of the compressor. Maintenance of heat pumps is necessary to prolong its operation and functions.