Broan® Automatic Make-Up Air Damper Application Guide Residential Use Only Read and Save this Information INSTALLER: Leave this guide with the consumer. Broan–NuTone LLC Hartford, Wisconsin www.broan.
About the Application Guide Congratulations on your purchase of the Broan Automatic Make-Up Air Damper! This product, called the “Damper” throughout this guide, is designed to keep your home well ventilated and comfortable for years to come. The Damper works automatically once it’s properly installed with a compatible Broan®, NuTone®, or BEST® exhaust device, so you won’t have to give your home’s exhaust systems a moment’s thought.
5. Do not connect the Damper directly to a combustion appliance of any type. 6. Before servicing or cleaning Damper, switch power off at service panel and lock the service disconnecting means to prevent power from being switched on accidentally. When the service disconnecting means cannot be locked, securely fasten a prominent warning device, such as a tag, to the service panel. 7. When performing installation, servicing or cleaning the Damper, it is recommended to wear safety glasses and gloves. 8.
6. Please read the Damper specification label on the product for further information and requirements. 7. The Damper’s outdoor air intake, ducting, and any filters should be inspected and maintained on a regular basis.
Table of Contents 1. 2. 3. 4. 5. 6. Definitions & Key Terms ........................................................................................... 6 What is Make-Up Air? .............................................................................................. 7 Broan Automatic Make-Up Air Damper – Product Function ..................................... 8 Different Models of the Broan Automatic Make-Up Air Damper ............................... 8 When to Use the Broan Automatic Make-Up Air Damper .
1. Definitions & Key Terms Within the scope of this document, several important terms are used. To give product installers and users a clear understanding, several key terms are defined below. Available static pressure: for the purpose of this guide, available static pressure represents the amount of suction that is available to draw in outdoor make-up air when the central air handler is running.
Direct-vented appliance: a fuel-burning appliance with a sealed combustion system that draws all air for combustion from the outside atmosphere and discharges all flue gases to the outside atmosphere. Also known as a sealed combustion appliance.1 Exhaust system: one or more fans that remove air from the building, causing outdoor air to enter by openings in the building shell.
Simply put, make-up air is air from outdoors and from other indoor spaces (e.g. transfer air) that is used to replace air that is exhausted.2,4 Outdoor air is air that is provided through natural infiltration across cracks and gaps in the building envelope as well as through intentional openings, like outdoor air ducts that are opened and closed as needed using the Broan Automatic Make-Up Air Damper.
The Universal model (MD*TU) can be used with any Broan, NuTone, or BEST range hood. Communications between the Damper and the Universal model’s pressure sensor at the exhaust device occur via an independent, hard-wired, low voltage connection. When an installation requires more than one Damper, Slave models (MD*S) may be specified for any additional Damper beyond the first, regardless of whether the first Damper is DirectWired, Universal, or LinkLogic™.
6.1 Applications with the LinkLogic™ Model (SMD* model) SmartSense® Whole-House Ventilation System with Damper Transformer Broan Smart-Sense Ventilation Fan - Make-up Air Damper Control Module Make-up Air Damper SMD* installed in air return duct of forced-air system (normally closed) The Damper works in sync with Broan’s SmartSense® whole-house ventilation system. When any one or more of the SmartSense® exhaust fans turns on, the Damper fully opens to allow fresh outdoor air into the home.
6.3 Applications with the Universal Model (MD*TU model) Broan Range Hood Pressure Switch Sensor Transformer Make-up Air Damper MD*TU installed in air return duct of forced-air system (normally closed) Any BEST, NuTone, or Broan Range Hood ‐ The Damper opens or closes based on a direct signal from a pressure switch kit that senses the exhaust duct static pressure caused by the operation of the range hood.
- When multiple Dampers are required, Up to four Slave Dampers may be directly connected to any primary Damper (whether LinkLogic™, Direct-Wired, or Universal) to increase the available make-up air volume. 7. Planning the Installation Planning the installation first requires selecting the most appropriate installation approach. The chart below offers suggestions for the most effective installation approach by considering a few important factors.
7.1.1 Using the On-line Range Hood Make-Up Air Specifier The Range Hood Make-Up Air Specifier (the “Tool”) takes the guess work out of specifying code-compliant make-up air systems by customizing an engineered design based on userentered building and system characteristics. All Tool inputs are selected using dropdown lists.
One of the key functions of the Tool is its ability to allow users to take credit for make-up air that is supplied through cracks and gaps within the building envelope. While the building code requires that some of the make-up air for range hoods over 400 cfm be provided through a system that can be “automatically controlled to start and operate simultaneously with the exhaust system” (e.g.
- If integrated with the return trunk of the central duct system, the outdoor air intake is located at least 10’ from the HVAC appliance. - Outdoor air intake is placed high enough above grade to prevent blockage from snow or other debris such as leaves, and at a minimum of 1’ above grade. - Make-up air damper should not draw air from crawlspaces, garages, attics, adjacent dwelling units, or any enclosed part of the building. The Damper should be installed to draw air directly from outdoors. 7.
When connecting the Damper to the return side of a central duct system in humid climates, consider having the HVAC contractor install controls that are configured to reduce the humidity of the incoming make-up air. For example, controls that start the central AC when the thermostat is in “Cool” mode and when the Damper opens, running the AC until a couple minutes after the Damper closes, can help to reduce the moisture in the incoming make-up air. 8.
9. Installation A separate set of Installation Instructions for the Damper is available from Broan and must be consulted for installations. The Application Guide does not contain specific installation instructions. To access the appropriate Installation Instructions, visit www.broan.com and enter the Damper’s model number in the Search box.
12. Frequently Asked Questions (FAQs) 1. What does the Broan Automatic Make-Up Air Damper do? The Broan Automatic Make-Up Air Damper (the “Damper”) provides a pathway for fresh outdoor air to enter a home when a compatible exhaust device is operating.
In homes with any one of these factors make-up air is advised. And in homes with more than one of these conditions, make-up air for the range hood is strongly advised. 4. What are the benefits of providing make-up air to replace air which is exhausted out of the home by a range hood or bathroom exhaust fans? Exhaust fans in a home are designed to pull out pollutants like cooking odors or moisture from a shower at the source, so they don’t linger in the home.
7. What are the different ways that the Damper can be installed in my home? The most common way to install the Damper is to connect it to a home’s central duct system. In this application, fresh outdoor air enters the home through the Damper and is then routed and distributed through the home’s ducts. More information on this installation approach can be found in the Typical Installations section of this Guide (section 8). 8.
