6 WAY ZONE VALVE

The most compact six-way zone valve in the HVAC industry with QM (Quick Mounting) assembly between the valve and the actuator, and directly connect to the flexible hoses. The six-way zone valve allows you to manage the supply to a single user from two different sources of thermal energy, or to easily manage 4-pipe systems (typically used in heating and cooling applications). A single actuated valve can substitute two or more actuated valves, easily resolving any complications with synchronization for the opening/closings of the two sources. The six-way zone valve allows the system change-over from heating to cooling within the quarter turn and also the simultaneous closing of the supply from both sources at 45°.

These valves are typically used in radiant ceiling systems, in particular for the service sector, where the change-over from heating to cooling can be easily managed, even when this is required during the same day, and can be carried out independently for each zone.

Automated Flow Balancing Valve

The Automatic Flow balancing Valve uses the latest flow technology to assure that the designed flow rate is achieved at all the times, in the whole system, irrespective of any pressure changes within the system. The solution ensures the desired flow rate for your cooling or heating water distribution system. In brass with 1/2″ sweat end connections, available with 0.5 GPM increments up to 6 GPM.

Pipes and other engineering services in industrial building

Dampers make up a critical part of HVAC systems and getting the selection right is vital to long term performance. Here’s what you need to know to choose the right damper.

The basics

Dampers are used to control airflow through certain portions of an HVAC system. You may need them to open and close or you may need them to modulate for variable airflow. They may be duct-mounted, wall-mounted or integrated into air handling equipment. Specialized dampers like smoke dampers limit the spread of smoke through ductwork and air transfer openings.

Dampers are constructed from metal (aluminum or steel) and consist of a frame and moving blades. The position of these blades determines how much air can flow through. Dampers may be have parallel or opposed blade arrangements. Parallel blade dampers are better suited to open/close applications while opposed blade dampers work well for modulating airflow.

Sizing and selecting a damper

Sizing a damper begins with the maximum airflow through the damper using the equation:

Airflow = Velocity x Cross-sectional area.

For dampers, the cross sectional area is the free area, which is the area available for air to flow when the damper is fully opened. Manufacturers publish this information in charts. Once you calculate your free area for a given velocity, use these charts to find the height and width for your damper.

To ensure that the dampers don’t create airflow problems in your system, the fan must be able to overcome the damper pressure drop. Depending on the situation, you may have to oversize your damper to reduce the pressure drop.

Fire damper for fire protection system on the roofing floor.

Choosing a velocity to size the damper depends on the application. The velocity for intake should be limited to 450-500 feet per minute (fpm) to prevent rain from entering. Exhaust velocities can go up to 1200 fpm.

Another decision you have to make when selecting a damper is whether the blades need to be weather-sealed or insulated. Weather sealed and insulated dampers are suitable for intake and exhaust dampers that are open to the exterior.

Controls

Dampers can be manual or automatic and with the increase in building automation, getting control right is important. This is where actuators come in. Our next article will discuss actuators in more detail.

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulent flows. Initial experimental validation of such software is performed using a wind tunnel with the final validation coming in full-scale testing.

At Enolgas USA, CFD is available for specific process and requests. Check out our Technical Support, the Conversion Calculator and the Flow Coefficient Calculator.