What is a mass spring/damper system?
The mass-spring-damper model consists of discrete mass nodes distributed throughout an object and interconnected via a network of springs and dampers. This model is well-suited for modelling object with complex material properties such as nonlinearity and viscoelasticity.
What is active mass damper?
The application of active mass damper (AMD) systems into buildings has been studied analytically and experimentally during the 1980s. The main purpose of these systems is to reduce the vibrations of buildings during strong winds or small earthquakes in order to improve the comfort of the building occupants.
Where are dampers used?
A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air-handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate control.
What are massive internal dampers in quake safe buildings?
Tuned mass dampers, also known as active mass dampers, are large masses mounted with flexible attachments, that are often used in tall structures. They work by reducing the amplitude of vibrations during an earthquake. When a building sways in one direction during an earthquake, the motion of the damper lags behind.
How much does a tuned mass damper cost?
Cost: $4 million Weight: 730 tons Number of steel plates: 41 Cable thickness: 3 1/2 in.
How do dampers work?
A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated.
Do all homes have dampers?
Not all homes havedampers. If you have a premium HVAC system with “zoned heating and cooling,” your dampers are automatically controlled by your unit. If you have dampers, you’ll find them on those runs, within a few feet of the unit itself.
Should damper be open or closed in winter?
In most homes, dampers going to the upstairs are open in the summer and closed in the winter. By closing the dampers to the upstairs in the winter, it allows for the heat to rise naturally after first being introduced into the lower levels of the home.
How do I know if my damper is open or closed?
Before lighting a fire, you can tell if the damper is open by placing your hand into the fireplace. If you feel a draft coming down the chimney, it is a good indicator that the damper is open. If you don’t feel any cold air coming down the chimney, it means that the damper is closed.
Should the damper be open all the way?
A fireplace damper should always be kept open while the fire is burning. Furthermore, keep the damper open until all the embers are done burning. By leaving the damper open, heat is being lost as warm air is being pulled through a hole in your living room (the chimney) all the way up and through the roof.
What’s the difference between a damper and a flue?
The flue is simply the open middle of the chimney that the smoke goes up. Dampers are sometimes miss-called flues or flutes, but they are something entirely different than the flue. A damper is intended to shut off- either fully or partially- the chimney flue.
What does a backdraft damper do?
A backdraft damper is one of the minute pieces needed to help the overall function and purpose of the ventilation system do its job correctly. A backdraft damper is able to allow contaminated air to flow out of the home but prevents contaminated air from sweeping back in to the home.
Where do you put a backdraft damper?
The backdraft damper will be approximately 1/4” (6mm) smaller than the duct or opening. 2. Insert the backdraft damper into the duct/opening (see Figure 3). Ensure that the bottom of the damper frame sits flat on the sill of the opening/duct to prevent twisting, sagging or uplifting.
How can Backdraft be prevented?
Most of the time, this is accomplished by cutting an opening in the roof and refraining from opening any windows or doors on or below the fire floor until conditions have changed. This means that no search and rescue can occur and no water is being put on the fire until the vertical ventilation can be completed.
How does a pressure relief damper work?
Pressure-relief dampers open and close automatically. The blades are kept closed by magnets. If the differential pressure exceeds the set maximum value, the magnetic force is overcome, and the blades open. The airflow by which the excess pressure has been caused can now flow through the damper.
What is a relief damper?
Pressure relief dampers are backdraft air dampers with an adjustable start-open pressure. This damper is generally used as a safety or controlling device. For example, mounting this damper on a duct section would relieve unexpected overpressure or relieve negative pressure downstream of a rapidly closing fire damper.
What is a backdraft damper for exhaust fan?
Backdraft dampers allow air to efficiently flow through exhaust ducts to the outside, yet prevent the unwanted flow of air into a house when the exhaust fans are off. These dampers are most often used in bathroom exhaust systems, clothes dryer vents, kitchen range hoods and microwaves.
What is gravity damper?
Backdraft dampers (also known as gravity dampers) are used in ventilation systems to allow airflow in one direction. and prevent airflow in the opposite direction. A relief damper is developed with an elevated and adjustable. start-open pressure while providing the backdraft function.
What is a louver damper?
Dampers and louvers control the flow of air in a process system or enclosed area. Louvers are a type of damper consisting of several blades mounted parallel across a duct. They are versatile and are a lightweight, compact, and have a low leakage to the outside environment.
What is butterfly damper?
Butterfly dampers are used to restrict the flow of materials in ducting systems where flow control and low leakage isolation are a priority. These dampers are especially useful in applications such as incinerators, balancing systems, control air systems, stack isolation, and scrubber systems.
How does a butterfly damper work?
Butterfly Dampers They control the flow of air or gas using a pipe system. A circular metal piece rotates on a vertical axis, opening and closing to start or stop the flow. This kind of valve is often used in safety applications such as fire prevention and environmental compliance systems.
How do you find dampers in ductwork?
Those two situations aside, locating your dampers should be pretty straightforward. Go to your furnace (be it in a utility room, crawl space, basement, etc.) and look at the main duct trunks radiating off the furnace. Dampers are almost always within 2-6 feet of the main trunk.
What type of valve is a butterfly valve?
rotary motion valve
How do you close a round ceiling diffuser?
Move the diffuser’s vent lever into the “Closed” position. The vent’s internal assemblies will close off the air flow; you may hear a slight whistling of air passing through the vent’s crevices if the air system is on. Although the vent is technically closed, it is still allowing air to escape through the narrow vents.
How do you know if a vent is open or closed?
When open, air flows freely; when closed (or almost shut), there’s little or no airflow. Have you ever wondered if an AC vent should be open or closed? If you are using your heating and cooling system, they should always stay open! Even in rooms you are not using.
How do I reduce the airflow in my HVAC?
Adjusting supply registers in rooms is the most accessible method of minimizing airflow into one room. Partially or completely closing supply registers reduces system airflow into that room alone, and also reduces airflow into the room return duct.
How do you close air duct dampers?
To adjust the damper lever, you will need to turn it to the left or right. If you want to close the damper, you will need to turn the damper lever in the opposite direction of the duct. If you want to open the damper, you will need to make sure it is running in line with the flex duct.
Is it OK to close HVAC dampers?
Bottom line: You probably shouldn’t close your air supply vents. Excessive static pressure inside an HVAC system is never a good thing. Closing too many air supply dampers could put you in the static pressure “danger zone.” Instead, have a pro measure the static pressure to see if you can safely adjust your dampers.
Should damper be open or closed in summer?
In the summer, a closed damper helps to keep cool, air-conditioned air inside the home where it belongs. 2. In the winter, when you’re not using the fireplace, a closed damper helps to keep cold air from swirling down into the house.
Are HVAC dampers necessary?
When you add zones to your HVAC system, your HVAC technicians need to install dampers to maintain the air volume in different zones in your location. These dampers stay inside your ducts and respond to calls for air in different zones, opening and closing as required.