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 VAV - Variable Air Volume  What is VAV? It is a mechanical device which regulates the flow of air in ducts. It generally consists of a blade or plate of different material as per the requirement to restrict the flow. It is used to cut-off the air supplied to any room from the central air handling unit. It can be operated manually or automatically. VAV work with a temperature sensor, It varies airflow at a constant temperature  when the set temperature on the thermostat is acheived automatically it reduces the flow by the closing damper and when temperature increased it open the valve which supplies more air to space to achieve temperature. VAV can be used for a single room or zone. It is available based on air quantity. It is also called an energy-saving device. It can be used for heating and cooling both purposes. Video On VAV  Construction and Working VAV comes in rectangular, oval as well as round form as per requirement. it has two openings on each end one for entry of air and oth

  MEP - M echanical E lectrical P lumbing   MEP refer to Mechanical, Electrical and Plumbing Civil engineering gives shape to building but MEP engineering brings facilities in building so that human can live a comfortable life.   Everything inside a building which makes it safe and comfortable to be incomes under the title building services. HVAC – HEATING VENTILATION & AIR CONDITIONING Heating As name suggest its main purpose is to generate heat which can be achieved by various equipment like heater, boiler, furnace or heat pump to heat water, steam or air in a central location such as a furnace room in a home or a mechanical room in large building. Ventilation It is a process in which air is replaced or exchanged for a particular area to control moisture, odours, smoke, heat, dust airborne bacteria, carbon-di-oxide and maintaining oxygen level. It has two types first one is natural ventilation in which air is exchanged naturally and the second one has forced Ventilation

 HVAC interview questions and answers 1.  What is ASHRAE &  ISHRAE?   American Society of Heating Refrigeration and Air-conditioning Engineers. Indian Society of Heating, Refrigerating and Air Conditioning Engineers. 2. What is COP and  Relative COP?  COP -  Coefficient Of Performance COP =Net Refrigeration Effect / Work Done Supplied It is the parameter on which efficiency is compared to air-conditioning units. It is calculated at 100% load. Relative COP =  ratio of actual COP and Theoretical COP 3.  What Is Btu? BTU = British thermal unit  It is the unit in which air-conditioning capacity defined. 1 TR = 12000 BTU/hr 4.Explain Refrigeration cycle?  Components that make a refrigeration system?. Watch the video with detailed explanation. 5. What Our Air Conditioning System and its function? and type of air-conditioning system? 6.  Which Gas used in   VRF? R410a 7. What is VRV and VRF?  http://learnhvac003.blogspot.com/2020/08/vrvvrf-overview.html 8. What is

  TR        -       Tons of Refrigeration - It Is a unit of refrigeration. -The rating of a refrigeration machine is given by a standard unit of refrigeration called Ton of Refrigeration. -One a ton of refrigeration (1TR) means the capacity to freeze 1 ton of water from and at 0’ in 24 Hrs. It's important to note that the freezing or melting of the ice represents a change-of-state only, which is considered a transfer of latent heat, as opposed to a change in temperature which is a transfer of sensible heat . Calculation • In USA 1 ton is taken as 2000lbs and its latent of fusion 144 B.Th. U/ lb  (334.9 KJ/Kg).                1 TR = (2000x144)/24                         = 12000 B  Th  U/ hr                         = 200 B  Th  U /Min                    1 B  Th  U =1.055 KJ                  1 TR =200 x1.055 KJ/Min                           = 211 KJ/Min                         1 TR = 3.517 KJ/s or KW Important Conversion   1 TR        =  12000 B  Th  U/ hr                  = 3.514 KW

  Thermodynamic System It is defined as quantity in space bounded by real or imaginary, fixed or movable boundaries across which energy take place from or to surroundings. External to the system is called surrounding or environment. A system with surrounding called a universe. Type of System Open System In this system, energy transfer takes place along with boundaries with mass transfer. Eg. Water in pool In pool mass and energy , both transfers can take place. Closed System In this system, energy transfer takes place with the outside environment through the boundary without mass transfer. Isolated System A system without mass and energy transfer is called an isolated system. Thermodynamic Equilibrium It is a state in which the system has a thermal and mechanical equilibrium. Energy It is the capacity to do work. Types of Energy Potential Energy It is the energy stored in an object due to its position relative to some zero position. Kinetic Energy It is the energy of a given mass due t