Refrigeration Pressure Switches | HVAC Systems

What you will learn from Refrigeration Pressure Switches

  1. A question from one of our readers - What are refrigeration pressure switches and how pressure switches protect the refrigeration circuit.
  2. All about high-pressure refrigeration switches
  3. All about low-pressure refrigeration switches
  4. Benefits of refrigeration pressure switches
  5. Refrigeration Pressure Switch Settings
  6. Refrigeration Pressure Switch Wiring Diagram
  7. Lots of related links to help you learn more

Richard - What are pressure switches used in refrigeration circuits and how do pressure switches protect the system from further damage? (more…)

DDC Outside Air Economizer System | HVAC Control

DDC Outside Air Economizer System | HVAC Control economizer dampersDDC Outside Air Economizer System  - Outside louvers allow the DDC control system to open dampers and introduce fresh air into the building. Building automation system, or the energy management system as it is sometimes called, monitors outside air temperature and humidity and based on a calculation and opens the outside air dampers when this calculation determines a precise set point. (more…)

Hydronic Pump Cavitation | HVAC Water Problems

Hydronic Pump Cavitation - Pump cavitation can cause severe problems to a pump if not addressed and corrected. To understand the cause of cavitation you need to understand the pressure-temperature relationship of the liquid in the loop. Whether it is water or water/glycol mix. As the water passes through the pump it changes the pressure from the suction side to the discharge side of the pump.

If the water’s static pressure drops too much vapor is created causing tiny bubbles in the water or fluid in the loop passing through the pump. These bubbles are unstable and collapse causing severe turbulence inside the bearing assembly and can damage the impeller. (more…)

Boiler Pressure Relief Valve | Boiler Safety

Boiler Pressure Relief Valve - Boiler Safety
The boiler pressure relief valve (PRV) is a safety valve designed to relieve an excessive build-up of pressure inside the boiler. The is a pressure vessel designed to handle a safe amount of pressure. If the pressure were to build up beyond the safety limitations as set forth by the design specifications the boiler system needs a safe way to vent the pressure to prevent an explosion. Furthermore, the boiler PRV is a safe way to vent excessive dangerous pressures inside the boiler. (more…)

R-134A Refrigerant Pressure Temperature Chart

R-134A Refrigerant Pressure Temperature Chart - R-134A is an inert gas also known as Tetrafluoroethane, and for air conditioner systems. Furthermore, R134A is a chemical refrigerant in automotive and domestic use air conditioners. Additionally, HVAC Systems such as chilled water systems in both commercial markets and industrial markets. You are very familiar with R134A if you are either an automotive mechanic or a chiller mechanic. R-134A uses the names Tetrafluoroethane, Genetron, or Puron, among other names depending on the manufacturer. Finally, The pressure-temperature chart represents the average pressure-temperature relationship of refrigerant R-134A.

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Air Handler Filter Pressure Sensor

Air Handler Filter Pressure Sensor and Low Static PressureAir Handler Filter Pressure Sensor - This is a pressure sensor. It tells a maintenance technician if the air filters are dirty and clogged. The pressure control is a low static pressure switch to trip the unit if the mixing box drops below the setpoint pressure. The pressure the switch is calibrated to.

In addition, the low static pressure sensor protects the fan and the ductwork including dampers from damage. If the economizer damper and the return air damper would fail closed (or another possible scenario) that would cause the unit to pull negative pressure in the mixing box. (more…)