by High Performance HVAC | Commercial HVAC |
The dampers straight across are outside air dampers or make-up air coming from an energy recovery unit. According to the mechanical code, commercial buildings require a certain amount of fresh air from the outside to maintain good IAQ for the occupants.
An energy recovery unit allows it to be conditioned before being introduced into the building. Other methods include using enthalpy calculations to open economizer dampers and/or CO2 control of the dampers. (more…)
by High Performance HVAC | Air Handlers |
Air Handler Water Coil Freeze Stat - The HVAC Air Handler Freeze Stat is a low-temperature limit control and it is used mainly in commercial systems in the ductwork on economizers or in air handlers just before any coil especially water coils. It is a safety and protection control to prevent extremely cold air from reaching the hot water or chilled water coils inside the air handler where the air enters from the economizer.
Under ideal control setup if the freeze stat trips the economizer dampers close and the blower fan stops. This prevents coils from freezing. A frozen coil can bust open and will need to be replaced if it freezes. This is the purpose of the freeze stat in HVAC air handler applications which utilize economizers for free cooling and other purposes.
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by High Performance HVAC | Direct Digital Controls |
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. (more…)
by High Performance HVAC | Air Handlers |
Air Handler Return Dampers | HVAC Components - These return air dampers serve a large air handler on a rooftop. This return air damper ends up in a mixing box inside the air handler where the return air from the building mixes with the outside air from the economizer. (more…)
