Four Approaches for a Quieter System
There is a misconception that VAV diffusers are noisy, but a review of their performance data shows that they have a pressure versus noise relationship similar to that of all diffusers. The difference is that VAV diffusers have a built-in VAV damper and can close to a minimum, possibly building up pressure in the system. It is the higher pressure that makes diffusers noisy, and because of this, a method of pressure control should be used in every VAV diffuser system.
Read More
Topics:
Diffusers,
Pressure Drop,
HVAC Fundamentals,
HVAC,
Engineering,
Design Engineering,
Tech Tip
An Essential Design Consideration for Mechanical Engineers
Pressure drop – the difference in pressure between two points in a fluid-carrying system – is one of the most critical design considerations for air distribution equipment in the HVAC industry. The problem with pressure drop for terminal units is that there are a number of metrics that are often confused with one another despite referring to different performance variables. These include static pressure drop, velocity pressure drop, pressure drop associated with acoustics and pressure drop associated with accessories.
Read More
Topics:
Pressure Drop,
Terminals,
HVAC Fundamentals,
HVAC,
Engineering,
Design Engineering
Creating Comfort, Efficiency and Sustainability with VAV Diffusers
High performance air systems demand modern design approaches with leading-edge
products and technology in order to optimize comfort and reduce energy consumption. A
comfortable environment is achieved by providing the smallest possible zones of temperature
control, allowing for individual temperature distribution and better air movement. Reduction
in energy is realized by designing a low-pressure HVAC system that allows for maximum
turn-down while maintaining temperatures.
Read More
Topics:
GRD,
Diffusers,
Static Pressure,
Pressure Drop,
Thermal Comfort,
HVAC Fundamentals,
HVAC,
Engineering,
Design Engineering
Consider Various Pressure Control Methods in a VAV System
All diffusers become noisier with higher pressures at their inlet and this is true for VAV diffusers. Pressure is often reduced by the use of a balancing damper or terminal unit, but VAV diffusers are unique as they have a built in VAV damper that can close down to a minimum flow.
Read More
Topics:
Diffusers,
Pressure Drop,
HVAC Fundamentals,
HVAC,
Design Engineering,
Tech Tip
In duct design and installation, system effect is the generation of higher than expected pressure drops through changes in duct direction or geometry. It can also be caused by improper installation of fittings, which result in excessive, unanticipated turbulence in the airflow. In short, system effect is the installed pressure drop which is different from the design pressure drop.
Read More
Topics:
System Effect,
Static Pressure,
Outlet Conditions,
Pressure Drop,
Velocity Profile,
Inlet Conditions
