Understanding Air Heater and Heat Exchanger Technology
An air to air heat exchanger basically uses a heat pump to transfer heat generated in a heating system directly from a hot air enclosure to the cool ambient air. The heat pump is evacuated tubes filled with a special liquid refrigerant. This refrigerant boiled when absorbing the heat energy from the incoming air at the air-exchange.
The basic design of this type of air-to-air heat exchangers makes it obvious that a large space must be available for its installation. As mentioned, the size of the heat pipes is such that it requires a long ventilation run inside the building where they are installed. This ventilation is important as it allows fresh air to enter the building in between the heated plates and then the cooled air must go through the condenser coil to reach the room. A condensing coil is a coil which absorbs heat and cold from the ambient air circulating around it.
The condenser consists of copper coils that are wound up tightly to form a dense metal film. Air enters the heat exchanger and passes through the condenser where it is absorbed by the refrigerant refrigerants and returns to the ambient air temperature. The refrigeration is necessary as it provides a controlled cooling of the incoming air stream so that it doesn't overheat the electronics attached to it. If the ambient air temperature is too high then the electronic equipment can overheat too.
The condenser fan used here draws in air from the outside of the building and blows it into the room. It is controlled by the temperature controller incorporated in the system. If ventilation is inadequate or insufficient then the condenser may not draw in enough fresh air for proper cooling. This will result in system malfunctioning and reduced efficiency.
Electronic heat exchangers are designed to work on the principles of electrical and thermodynamics. Electrical vibrations, induced by passing electricity through them, are supposed to generate heat energy and in the process transform it into mechanical movement called convection. But sometimes the electrical vibrations do not generate enough heat energy for the system to function properly and there will be a gap between the heated output and the amount of fresh air being drawn in by the heat exchanger. In this case fresh air is not allowed to enter the system.
Mechanical conduction is another way of transferring heat. In this case, the mechanical conduction elements move air into the electrical enclosure through a ventilating duct or a refrigeration duct. Sometimes the heat load in the electrical enclosure may exceed the maximum safe level indicated in the electrical wiring. In such cases, the system will have to be manually switched off and the wiring corrected. If the internal heating system has a thermostat programmed to maintain a particular heat load limit, then manual switching of the heat load will also be required.
The third option is to install a heat pipe. A heat pipe consists of a flexible metal pipe insulated on both sides and connected to the inside of an electrical enclosure. When the system becomes inefficient, the metal conduction allows hot air from the furnace to pass through the heat pipe and warm up the air inside the electrical enclosure. As the system becomes more efficient, the heat pipes may need to be replaced. To reduce air loss, the electrical enclosures should be installed very tightly and the pipe must also be properly insulated.
Air conditioners are very useful when they are operating at higher temperatures. However, it is necessary to keep in mind that the system needs to be regularly maintained to achieve maximum cooling efficiency. Air heat exchangers also help in achieving this, but at a much higher cost of maintenance. Regular inspection, lubrication and cleaning of the air conditioning unit, condenser and pipes will achieve maximum cooling efficacy and prevent it from working inefficiently. If these simple maintenance measures are followed, then the air conditioning unit will work efficiently for a long time.