What is a fan powered VAV?
In a series fan-powered variable air volume (VAV) system, each zone is conditioned by a box with a small fan that draws-in plenum return air and mixes it with supply air from a primary system. The primary system is similar to variable air volume (VAV), with the primary air supplied at a fixed temperature.
What are the main types of VAV?
There are two primary types of VAV systems—single-duct and dual-duct.
What is the difference between a VAV and a fan powered box?
In many VAV systems, the exterior zones will utilize fan-powered terminal units. When compared to a single duct terminal unit, the fan-powered versions have a fan that enables the induction of plenum air into the airflow.
What are four common types of VAV boxes?
These terminal units, commonly referred to as VAV boxes, are used to control the volume and, sometimes, the temperature of air entering a designated space. There are a few different types of terminal units used in today’s developments: single duct, parallel fan-powered, and series fan-powered.
What is VAV actuator?
Variable Air Volume (VAV) is a type of heating, ventilating, and/or air-conditioning (HVAC) system. The VAV Zone Controller has a built-in actuator and maintains zone temperature by operating the terminal fan and regulating the flow of conditioned air into the space.
What is single zone VAV?
Single zone VAV, or single zone variable air volume, is an HVAC application in which the HVAC unit varies. the airflow at constant temperature to provide space temperature control. A constant volume HVAC unit supplies constant airflow with variable temperature to provide temperature control.
What is a multi zone VAV?
Background. Multiple-zone VAV systems have existed for more than forty years. One reason they continue to remain popular is that they save fan horsepower at part load by reducing airflow. These systems can utilize direct expansion or chilled- water cooling and serve just a few or many zones.
What are VAV terminal units?
A VAV terminal unit, often called a VAV box, is the zone-level flow control device. It is basically a calibrated air damper with an automatic actuator. The VAV terminal unit is connected to either a local or a central control system.
What type of supply fan is recommended for the air source in a traditional VAV system?
Axial fans are used in VAV applications, but the use of centrifugal fans is more common. We will show the current methods of fan volume control using centrifugal fan types as examples.
What is a fan powered terminal unit?
A fan powered terminal unit, commonly referred to as a fan powered box, is an air terminal unit which contains both a primary air inlet, as well as a local motor and blower assembly. Fan powered terminals generally come in either a parallel or series arrangement, determined by the location of the fan in the assembly.
What is the fan powered variable air volume (VAV) terminal size?
Johnson Controls Series Fan Powered Variable Air Volume terminals are available from 100 to 4600 cfm, offering tremendous flexibility to meet a wide variety of HVAC systems design requirements.
What is a fan powered VAV box?
Modular Fan Powered VAV Box is designed to integrate into or below raised access floor panels and force air circulation through the system. The size and configuration of the FTU will vary depending on whether it’s to be used in a low-profile or standard-height access floor.
What are the different types of fan powered and shut off boxes?
VAV Box Types Fan Powered and Shut Off 1 Cool only single ducted series 2 Fan-powered single duct series with reheat 3 Fan-powered single ducted parallel with reheat – uses plenum air before using reheat for energy efficiency
What is varitrane Vav?
VariTrane fan-powered terminal units reduce energy use and operating cost with Electronically Commutated Motor (ECM) and modulating airflow control algorithms. This generation of VariTrane units builds upon history and expands the products into the most complete VAV offering in the industry.