I usually use gravity dampers they are less expensive and last longer than spring or powered dampers unless you use fire rated powered dampers at 20 × the cost of a gravity damper. Spring dampers work but need cleaning in my experiance after 3-4 years. So for a no hassle long life make up air system I use gravity.

What are dampers in ventilation?

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.

When should a fresh air damper open?





(2) In manual damper control systems, someone should open the damper when the building is occupied (to some pre-arranged set point) and then close the damper when the building is unoccupied and the OA dew point temperature exceeds 55F.

How do you install makeup air unit?

Quote from the video:
Quote from Youtube video: If you have return air if you have air conditioning unit some type of duct forced duct in the house you can run that air right into the return air if not you can run. It into the basement.

Do you need a fresh air damper?

It provides fresh air without drafts. But some homes get too dry with this source of winter fresh air. Rather than close it off, it is recommended that you install a damper in this line to allow you to turn it down, using window condensation as a guide for the right setting.

Do I need a damper on fresh air intake?

Closing the Supply of Air from Outside



Typically, a fresh air intake is operated using a damper. First, locate the intake, which is usually placed in the attic, but it may also be ducted to the central air handler’s return side. Avoid covering an intake with a drape or curtain or stuffing it with insulation or rags.

What does a mixed air damper do?





The mixing plenum normally combines two air streams, and includes for three sets of dampers: one for the fresh air, one for the exhaust air, and a mixing damper between the two air streams. The mix of fresh air and recirculated air can thus be adjusted to suit the needs of the building’s occupants.

How do you put fresh air in a tight house?

Supply Ventilation: Supply ventilation systems use a fan to pressurize your home, forcing outside air into the building and stale air to leak out through holes in the building envelope (bathroom fans, kitchens fans, etc.)

How do you bring fresh air to a room?

Bring as much fresh air into your home as possible

  1. If it’s safe to do so, open doors and windows as much as you can to bring in fresh, outdoor air. …
  2. If you can, open multiple doors and windows to allow more fresh air to move inside.

How does fresh air damper work?

The Fresh Air Damper (FAD) is a 24VAC power-open, power-close motorized air damper designed for installation in a fresh air ventilation duct connected to an outdoor air intake hood and a duct fan or the HVAC return plenum, to control the flow of fresh air into the home.

Can I put a filter on my fresh air intake?



If the home is equipped with a fresh-air intake that is ducted to the air handler, a filter should also be installed at the fresh-air intake. Additionally, the fresh-air intake should be located where it is accessible so the filter can be cleaned or replaced as needed. Home inspectors can also check for this.

What is return air damper?

An AHU typically has dampers that are used to control the amount of out- door air that enters the system, the amount of air exhausted from the system, and the amount of return air from the building that is recirculated through the system.

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 are the 3 types of dampers?



In this guide, we will walk you through the main types of industrial dampers, and their applications, to help you with your decision making process.

  • Multi-Blade Control Dampers. …
  • Single Blade Dampers. …
  • Backdraft and Pressure-Relief Dampers. …
  • Face and Bypass Dampers. …
  • Inlet Vane Dampers. …
  • Isolation Dampers.


How many types of dampers are there?

Dampers are one of the important elements in HVAC. They control airflow as well as prevent the spread of fire and smoke.

Are dampers bad for HVAC?

If you’re thinking, “Hey, closing off my air supply dampers might also increase static pressure,” you’d be right! A fully or partially closed damper pushes back against the air being forced through the system by the blower fan. It increases air resistance inside your ductwork.

What is the difference between louver and damper?



The Louver is a kind of a shutter or blind that comes with horizontal slats that are angled to allow space for light and air but restrict rain and direct sunlight whereas dampers control the airflow. In HVAC systems, dampers and louvers are used to regulate the flow of air.