Broan MD8T 8-In. Automatic Make-Up Air Damper

Broan’s MD8T 8-inch automatic make-up air damper is designed to provide make-up air control for exhaust devices. Used with slave dampers, they open in unison to provide synchronized operation of kitchen, bath, and whole-house ventilation products.

Wired to the transformer using low-voltage wiring, this 8-inch automatic damper is signaled to open and close while the range hood is in operation. This ensures optimum performance in a variety of applications.

Feature Highlights

• Direct Wire Design: Works with select range hoods to balance indoor air pressure by providing interlocked make-up air. They close as soon as the range hood is powered off.
• Save Energy: Interlocked make-up air systems save energy by not allowing unwanted air into the home during heating or cooling, so air pressure is equalized.
• Meet IRC-Based Requirements: Using make-up air dampers to control it, IRC-based requirements for make-up air are met.
• Group Dampers: You can “gang” dampers together to provide a cost-effective means to provide higher volumes of make-up air.

When Do You Need the MD8T?

The Broan MD8T is useful in homes or cabins with natural-ventilated combustion appliances like a water heater or natural-draft fireplace. These tend to be more susceptible to improper venting in cases of depressurization.

Make-up air is also needed in homes with large range hoods (over 300 CFM) and in newer energy-efficient “tight” or “green” homes that are tightly sealed.

Benefits of Using a Make-Up Air Damper

• Filtration: Since the make-up air is entering your home at a known point, it can be filtered before entering.
• Effective Exhausting: When fresh outdoor air is drawn into your home, pollutants are more effectively exhausted, improving ventilation.
• Reduce Negative Pressure: When air is exhausted without being replaced by fresh outdoor air, negative pressure conditions can become severe, interfering with the correct operation of combustion equipment.

Summary

The Broan MD8T 8-inch Automatic Make-Up Air Damper features a direct wire design to provide control for make-up air in kitchens, baths, and whole-house ventilation. Wired to operate in conjunction with slave dampers to open and close while the range hood or bath fan is in operation.