D

Damper - A damper is a device for controlling the flow of air or smoke in a chimney or woodstove. In its most common form, it is a plate located in the fireplace or stove pipe with a control handle. For some stoves there is an additional air control damper located on the exterior of the stove.

Damper Cap & Top Mount Damper - Located on the top of the chimney. Works by closing off the top of the flue when not in use so that cold air does not enter the home and that heat/cold air does not get drawn up an open flue. A cable is run down the side of the flue and attached to the side firebox wall. The cable controls the opening and closing of the damper. Damper caps are like any other chimney cap but with an integrated damper. Damper caps and top mounted dampers often have a gasket that helps seal the opening, therefore they are generally more energy efficient than traditional dampers.

Direct Vent - A sealed combustion system that utilizes a flue pipe to draw air for combustion from the exterior of your home and a flue pipe inside of this pipe that exhausts combustion gasses outside. 

Draft - The rising gas creates a pressure difference called draft, which draws combustion air into the appliance and expels the exhaust gas outside through the chimney.

Draft Hood - The draft will change in a chimney as exhaust vents towards it, especially when going from cold air to hot. A draft hood is placed above the upper most part of gas appliances such as a furnace or water heater, to draw air into the chimney, creating a consistent air flow without any wind gusts or sudden temperature spikes or drops. Hot air, if not put through a draft hood would create a strong air flow through the burners. A draft hood significantly cools the air as it is released by the burners, causing condensation if the system is not calibrated properly.

Dryer Vent - A vent connected to a clothes dryer that is used to screen lint and remove exhaust.

Dryer Vent Cleaning - Dryer vent cleaning is a service in which the built up lint is removed from the dryer venting systems. Lint that normally occurs in a clothes dryer can build up over time. Build-up of lint causes the dryer to take more time in drying clothes and becomes a fire hazard.