HVAC TECH

  HVAC System Selection and Selection Guide     A first step in Central system design involves determination of the individual zones to be conditioned and the type and location of the HVAC equipment.large buildings with variable needs in the different zones can be served well with a central system,in which most of the HVAC equipment is located in one or more mechanical rooms.the energy and moisture addition or removal, the ventilation, and the removal of pollutants can be accomplished by the equipment in the mechanical room. Normally mechanical rooms are outside the conditioned area, in a basement, on the roof, or in a service area at the core of the building. Mechanical rooms reduce the noise, spills, and mechanical maintenance that might otherwise occur in the occupied spaces. Equipment normally found in the central mechanical room includes: Fans or air handlers for moving air with associated dampers and filters Pumps for moving heated or Chilled water and appropriate c...

 Basics of HVAC Basics of HVAC and What is HVAC system is explained in this video so watch it till the end.

  Compressor     The compressor is mechanically the most complex and is often the most expensive single item in the system. A more complete discussion of compressors can be found in the ashram handbook, HVAC system and equipment volume.       Compressors may be of two basic types: positive displacement and dynamic.positive displacement compressors increase the pressure of the refrigerant vapor by reducing the volume. Examples are the Reciprocating, rotary,(rolling piston, rotary vane, single screw, and twin screw),scroll, and trochoidal . Dynamic compressors increase the pressure of refrigerant vapor by a continuous transfer of angular momentum to the vapor from the rotating member followed by a conversation of this momentum into a pressure rise. The centrifugal compressor is of this type. Reciprocating compressors .                                        ...

  Vapour Absorption Cycle Vapour Absorption Cycle:- The Vapour Compression Cycle has been a most commonly used cycle for refrigeration in HVAC system.It provide efficiency, reliability, practically demanded by users.The Absorption system has found it's niche where there is large quantity of inexpensive or waste heat available. Changing economics and fuel availability have influenced the selection of these types of system.These system have the ability to furnish heating and cooling simultaneously.       The environmental concerns with many of the halocarbon refrigerant have drawn more attention to absorption system,since the commonly used working fluids of these systems have a benign effect on atmosphere.      Above image illustrates tha essential features of the absorption cycle.Note that the compressor of the vapour Compression Cycle has been replaced by the generator, absorber, and pump and that the solution of refrigerant and absorbent circul...

Expansion valve fitting and Adjustment    We all know the what is Expansion valve and it's operation, If you want know about it click on following link https://lavate456.blogspot.com/2019/10/expansion-valves-expansion-valve-is.html .  Now we are going to discuss about the Fitting of New Expansion valve and it's expansion setting adjustment.     Before starting the Fitting procedure of expansion valve we have to check the refrigerant pressure in the system it should be zero as shown in below link. The valve orientation should like that the head of valve should not be on down side. It should be on top side or horizontal side as shown in below image. While the soldering do not place open flame on the capillary bulb or near the capillary bulb. After fitting the expansion valve we have to connect the capillary bulb or external equalizer with the expansion valve.The location of the bulb and equalizer should not be on a vertical line. It should be on a horizontal line ...

 Chiller Approach Chiller Approach is a essential check point for ensuring that the chiller is a running at peak efficiency.When the chiller condenser approach temperature is within operating range,it indicate the condenser tubes are clean and chiller runs efficient.When increased approach temperature reduces the efficiency and it need maintenance. What is Approach Temperature? Chiller Approach temperature is the temperature difference between the liquid refrigerant temperature that leaving the condenser and the leaving cooling water temperature.This temperature difference is called chiller approach temperature. Effects of Approach Temperature:- If the  Condenser approach temperature is within the operating range that indicate the condenser coils are in good condition and cleaned.In this condition chiller runs efficiently. If the condenser approach temperature is out of the operating range that indicate the condenser coil scaled from inner side due to which heat transfer not d...

 Law's of Thermodynamics Thermodynamics Laws describe the physical quantities such as Energy, Temperature, entropy that define the Thermodynamics systems at Thermodynamics equilibrium.The laws explain the relation between this quantities There are four laws of Thermodynamics let's check it out. 1) Zeroth Law of Thermodynamics:- Zeroth Law state that the when the two bodies are in a thermal equilibrium with the third body, Then that two bodies are in a thermal equilibrium with each other's. 2) First Law of Thermodynamics The first law of Thermodynamics is a version of law of energy conservation It state that the total energy of an isolated system is constant,it can be transferred from one form to another form, but can neither be created nor be destroyed. For a Thermodynamics process without transfer of matter first law is  Often formulated 3) Second Law of Thermodynamics:- When two initially isolated body separate but in a nearby region,each in Thermodynamics equilibrium wit...

How to remove oil fouling in HVAC system What is oil fouling ? Oil fouling is known as oil accumulations of unwanted oil falls in HVAC system. At the time of refrigerant compression process oil migrates from the Compressor to the coil system contaminants the metals of coil that heat transfer.Due to that coils heat transfer rate decreased. Compressor that uses oil for its lubrication purpose, Even the smallest amount of oil in the coil system creates a film or coating that will hinder a heat transfer and reducing the efficiency of system How do you remove oil fouling? By using a synthetically enhanced refrigerant additive like bluemaxx you remove oil fouling,increase efficiency and save money on air cooled and water cooled system. Bluenaxx is a stable, non-corrosive liquid that will added in a refrigerant of a cooling system.That will help to increase the cooling capacity and reduce heat loss.

Qualifications Equipment is the one of the basic components of every company.Before selecting any machine company needs to cover below points. 1) User requirements Sheet 2) Design Qualifications 3) Installation Qualifications 4) Operational Qualifications 5) Performance Qualifications 1)User Requirement Sheet - Customer of the equipment has a certain expectations about the equipment which he wants to use.Some of the general requirements may be stated in the form of certain parameters like. -Size of equipment -Speed of equipment -Effectiveness of equipment -Availability of spares -Ease of operation,maintenance,cleaning -Low dust and sound generation -Lesser breakdowns -Easy Changeovers 2) Design Qualifications:- If the equipment is to be fabricated as per user requirements then it is very essential to design detailed Qualification document.It is advisable to work out the detailed equipment specifications by sitting together with the manufacturer.Once this is ready it is agreeable to pur...