Tag Archives: Pressure

Refrigeration Pressure Switches | HVAC Systems

 Refrigeration pressure switches -

Refrigeration Cycle Component Diagram for Air Conditioners and Heat Pumps

Refrigeration Pressure Switches | HVAC Systems

Richard – What are pressure switches used for in refrigeration circuits and how do pressure switches protect the system from further damage?

Refrigeration Pressure Switches

Thanks for the question and for being a reader of High Performance HVAC! First there two types of basic refrigeration switches in the typical high grade residential system. I say high grade because not every refrigeration system in air conditioners and heat pumps have switches to protect the refrigeration system.

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Water Tower Pumps and Controls | Pumping Systems

Water Tower Pumps and ControlsWater Tower Pumps and Controls | Pumping Systems

Water Tower Pumps and Controls | Pumping Systems – Water towers maintain a ready limited supply of water for communities in the event the water main goes down. Many towers are used for emergency situations for the fire department to have water for fighting fires and for water fire suppression systems to have a supply of water for the emergency if it should arise.

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Hot Water Boiler Components and Controls | Combustion Control

Hot Water Boiler Components and Controls | Combustion Control

Hot Water Boiler Components and ControlsThis photo shows the boiler cabinet open exposing controls and basic components of the boiler. The module on the left is the ignition control module which controls the sequence of operation for ignition and burner controls of the boiler. When the boiler is enabled to run usually by a thermostat or controls the ignition control module begins the process of firing the burners. The process typically begins by having the ignition module check the safety circuit to ensure all safeties are normal and not in alarm. This includes energizing the inducer or forced draft fan motor and any limit switches and a flow switch to ensure the boiler has water flow.

Hot Water Boiler Components and Controls | Combustion Control

The inducer or forced draft fan motor causes some pressure switches to close proving that combustion air is available and that the combustion gases will be exhausted when the burners fire. After the safety circuit has been proven to be okay the ignition control opens the gas valve while simultaneously activating the spark ignition to ignite the gas now being supplied to the burner(s). Once the burners ignite the fire is proven, usually by a state of the art flame sensor, the ignition control module deenergizes the spark ignition. As the water heats up it is sense by an aquastat or temperature sensor. When the temperature of the water reaches the set point of main boiler controller the ignition control closes the gas valve and the main burners shut down. The inducer or forced draft fan motor continues to run for period of time so that all the combustion gases in the system are purged up the boiler flue or boiler stack.

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DDC Outside Air Economizer System | HVAC Control

DDC Outside Air Economizer System | HVAC Control  economizer dampers

DDC Outside Air Economizer System

DDC 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. Introducing outside air into the building not only makes common sense it is also required by the Mechanical Code in commercial applications. This is required mainly for health reasons as it rids the building of volatile organic compounds and CO2 which is naturally produced by humans. Large concentrations of CO2 can build-up inside the building and needs to be vented as too much CO2 negatively affects human health. It is therefore important that along with the intake of outside air into the building there needs to be an exhaust air damper to maintain good building pressure. Negative pressure inside a building is bad as it causes infiltration moisture issues which leads to mold and mildew. Too much pressure also creates its own problems so it is important, with an outside air damper system, to monitor and maintain building pressure. Enthalpy wheels add to the efficiency of a good economizer system.

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HVAC Definitions Terms & Acronyms | Heating Cooling

HVAC Definitions Terms & Acronyms

This is a comprehensive list of HVAC Acronyms and HVAC Terms. High Performance HVAC is certain there are more terms and acronyms. If you know of something we missed please email us. Thanks!

HVAC Definitions Terms & Acronyms - VSD or Variable Speed Drives

VSD or Variable Speed Drives

AC – Air Conditioning or Alternating Current

ACCA – Air Conditioning Contractors Associations

AFUE – Annual Fuel Utilization Efficiency

AHU – Air Handling Unit

AI – Analog Input

AMCA – Air Movement and Control Association

AO – Analog Output

AQS – Air Quality Systems

ASHRAE – American Society of Heating, Refrigerating, and Air Conditioning Engineers

AV – Automatic Air Vent

AWG – American Wire Gage

B – Boiler

BACnet – Computer communication protocol for building automation systems and control networks

BAS – Building Automation System

BI – Binary Input

BMS – Building Management System

BO – Binary Output

BP – Backflow Preventer

BTU – British Thermal Unit

BTUh – Brtish Thermal Units per Hour

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THURSDAY, JULY 31, 2014