Thursday, 22 December 2016

Ventilation Control !!!

Ensure Good Ventilation to Avoid Health Hazards !!!

All occupied buildings require a supply of outdoor air. Depending on outdoor conditions, the air may need to be heated or cooled before it is distributed into the occupied space. As outdoor air is drawn into the building, indoor air is exhausted or allowed to escape (passive relief), thus removing air contaminants. The term “HVAC system” is used to refer to the equipment that can provide heating, cooling, filtered outdoor air, and humidity control to maintain comfort conditions in a building. HVAC systems range in complexity from stand-alone units that serve individual rooms to large, centrally controlled systems serving multiple zones in a building. 

Some buildings use only natural ventilation or exhaust fans to remove odors and contaminants. In these buildings, thermal discomfort and unacceptable indoor air quality are particularly likely when occupants keep the windows closed because of extreme hot or cold temperatures.
In order to exhaust air from the building, make-up air from outdoors must be brought into the HVAC system to keep the building from being run under negative pressure. This make-up air is typically drawn in at the mixed air plenum as described earlier and distributed within the building. For exhaust systems to function properly, the control air must have a clear path to the area that is being exhausted. To prevent operating the building under negative pressures (and limit the amount of unconditioned air brought into the building by infiltration), the amount of make-up air drawn in at the air handler should always be slighter greater than the total amount of relief air, exhaust air, and air exfiltrating through the building shell. Excess makeup air is generally relieved at an exhaust or relief outlet in the HVAC system, especially in air economizer systems. In addition to reducing the effects of unwanted infiltration, designing and operating a building at slightly positive or neutral pressures will reduce the rate of entry of soil gases when the systems are operating. 

The selection of a specific ventilator should be based on the following factors:

  • Job details such as the atmospheric hazard, the size of the confined space, etc…
  • Airflow required
  • Airflow volume required at the end of the duct to control the hazards present; and
  • Breeze to ensure worker comfort in the space.
  • Duct friction loss to ensure adequate air volume reaches the end of the duct.

Aims of HVAC Control Systems:

HVAC Control Systems are used for the following benfits:
  1. Lower energy cost.
  2. Lower operations cost.
  3. Increase flexibility.
  4. Ensure quality building environment.
Esaplling Pvt. Ltd.
Contact no:020-65366661

Monday, 5 December 2016

Refrigeration Cycle..!!!

Air conditioning and refrigeration are provided through the removal of heat. Heat can be removed through radiation, convection, or conduction. Refrigeration conduction media such as water, air, ice, and chemicals are referred to as refrigerants. A refrigerant is employed either in a heat pump system in which a compressor is used to drive thermodynamic refrigeration cycle, or in a free cooling system which uses pumps to circulate a cool refrigerant.

Refrigeration cycles is accomplished by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. Evaporation occurs at a low temperature and low pressure while condensation occurs at a high temperature and high pressure. Thus, it is possible to transfer heat from an area of low temperature to an area of high temperature.

The refrigeration cycle uses four essential elements to cool.

Compressor- Is the heart of the system. Just like your heart pumps blood through your body at a specific flow rate and pressure, the compressor pumps the refrigerant through the air conditioning system at a designed flow rate and pressure.

Condenser- The high temperature refrigerant passes into a condenser coil. As the vapor refrigerant travels through the coil, air from a fan passes over the coil to cool the vapor refrigerant. As the vapor cools it condenses and becomes a liquid, this is referred to as a “change of state”. This “change of state” from vapor to liquid is essential.

 Metering Device- Controls the flow of the liquid refrigerant to the next component which is the evaporator. This is a dividing point between the high pressure and low pressure sides of the system. As this high pressure liquid is passing through the metering device and into the evaporator the pressure drops.

Evaporator- After leaving the metering device the refrigerant immediately enters a coil called the evaporator. This coil or evaporator has a fan blowing across it. As the refrigerant enters the coil at a lower pressure it begins to bubble and boil and “change state” back to a vapor. During this process of changing state, energy in the form of heat is being removed from the air passing over the coil and is being absorbed by the refrigerant. The heat that was in the air is transferred into the refrigerant. Since heat was removed from the air blowing over the evaporator coil, the air leaving the evaporator coil is cold. You see that an air conditioner makes cold air by having the heat that is in the air absorbed into the refrigerant.

The Cycle Of Cooling

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Thursday, 6 October 2016

Highly Robust Cleanrooms Solution!!!

Flexible, Specialized Clean room Services..
We provide clean rooms solution maintaining the class as per standards good manufacturing practices( GMP) along with Epoxy full furnished solution suitable for the plant. A cleanroom is a controlled environment where products are manufactured. In the pharmaceutical sector the commercial survival of the manufacturer depends on the integrity of the finished product. The only way to control contamination is to control the total environment. Air flow rates and direction, pressurization, temperature, humidity and specialized filtration all need to be tightly controlled. And the sources of these particles need to controlled or eliminated whenever possible. There is more to a clean room than air filters. Cleanrooms are planned and manufactured using strict protocol and methods. They are frequently found in electronics, pharmaceutical, biopharmaceutical, medical device industries and other critical manufacturing environment. However, it is important to remember that the quality control and standard operating procedure (SOP) requirements of a clean room are prerequisites for a successful clean room operation. A cleanroom can be defined as an environment where the supply, distribution and filtration of clean air and the material of construction are regulated to meet the appropriate cleanliness levels required.
Key Elements of Contamination Control-
HEPA(High Efficiency Particulate Air Filter) - These filters are extremely important for maintaining contamination control. They filter particles as small as 0.3 microns with a 99.97% minimum particle-collective efficiency.
 CLEANROOM ARCHITECTURE - Cleanrooms are designed to achieve and maintain a airflow in which essentially the entire body of air within a confined area moves with uniform velocity along parellel flow lines. This air flow is called laminar flow. The more restriction of air flow the more turbulence. Turbulence can cause particle movement. 
FILTRATION - In addition to the HEPA filters commonly used in cleanrooms, there are a number of other filtration mechanisms used to remove particles from gases and liquids. These filters are essential for providing effective contamination control. 
CLEANING - Cleaning is an essential element of contamination control. Decisions need to made about the details of cleanroom maintenance and cleaning. Applications and procedures need to be written and agreed upon by cleanroom management and contractors (if used). There are many problems associated with cleaning.
contact us:020-65366660