Heating, Ventilating and air-conditioning is known as HVAC. HVAC systems are used to provide ventilation and reduce air infiltration and maintain the pressure relationships between spaces. HVAC systems are vitally important for the preservation of historic artifacts. The main purpose of HVAC is to maintain good quality of air through ventilation with filtration and provide comfortable air. It is Easier to maintain due to reduced number of components and few units to access.HVAC chillers vary in terms of condenser cooling method, cooling specifications and process pump specifications.

There are several condenser cooling methods. HVAC chillers include a compressor, condenser, thermal expansion valve, evaporator, reservoir, and stabilization assembly. The components used in HVAC systems were hand held with industrial revolution. HVAC systems are playing a main role of maintaining proper air flow. It needs a proper amount of designed air flow through out the HVAC system. To maintain the proper air flow HVAC air filters are needed, there are three different types of air filters are used to maintain the proper air.

Magnetic bearing is used to support rotating and linear moving machinery elements without contact with rotor thus it accomplished by electro magnet. Magnetic bearings support moving machinery without any physical contact. There main e three components that make up magnetic bearing, are actuators, sensors and control system. The main advantage of magnet bearing is there is no lubrication, free abrasions, free of wear maintenance good thermal isolation of the rotor and stator and small bearing loss. Magnetic bearings are also used to support maglev trains in order to get low noise and a smooth ride by eliminating physical contact surfaces. Magnetic bearing will not affect friction or wear, and therefore they offer an unlimited lifetime while no maintenance is needed. It is used in an increasing number of commercial high-performance applications in the domain of rotating machinery. The main use of magnetic bearings as an actuator for noise control.

A heat pipe is a heat transfer machine that can transport large quality of heat to very small temperature between hotter and colder interface. Heat pipe is a simple device that can quickly transfer heat from one point to another. Heat pipe is in a shape of hollow cylinder which is filled with vaporizable liquid. It works like first heat is absorbed in a evaporating section and fluid boils to vapour phase. Then heat is released from the upper part of the cylinder to the environment.

Now vapour condenses to liquid phase and liquid returns by gravity to the lower part of the cylinder. It may also describe as Heat pipes are having two sections like precool and reheat. The main advantages of heat pipe are the passive heat exchange without any moving parts. The cooling or heating equipment size can be reduced. There is no cross contamination between air streams. Some disadvantages are it require two air streams be adjacent to each other. And the air streams must be relatively clean and may require filtration.

Sensotronic Brake Control (SBC) is a control of various factors like wheel speed, breaking force for each wheel, steering, etc. Sensotronic Brake Control is used to pass the drivers breaking commands to a micro computer which process various sensor signals and it calculates the optimum brake pressure for each wheel. Depending on the pedal force, the master brake cylinder builds up the appropriate amount of pressure in the brake lines.

Another main use of this Sensotronic Brake Control is that this break calculates the force separately for each wheel. And also in Sensotronic Brake Control full braking power is available even when the engine is switched off. Sensotronic Brake Control Drive-Away Assist prevents the car from rolling backwards or forwards. It slows down the car to standstill at a steady rate of deceleration. Sensotronic Brake Control also offers more safety than a conventional brake system and it also offers the possibility of assigning brake forces in a way appropriate to the situation.