HVAC and BEMS

Digital to Analog

Digital to Analog Conversion

HVAC term for controls that vary airflow through an air outlet, inlet, or duct.  A damper position may be immovable, manually adjustable, or part of an automated control system.

A device that controls the opening and closing of a damper in HVAC systems.

Demand Controlled Ventilation

A deadband (sometimes called a neutral zone) is an area of a signal range or band where no action occurs (the system is dead).  Deadband is used in voltage regulators and other controllers. The purpose is common, to prevent oscillation or repeated activation-deactivation cycles (called "hunting" in proportional control systems).

A unit for measuring the extent that the outdoor daily average temperature (the mean of the maximum and minimum daily dry-bulb temperatures) falls below (in the case of heating, see Heating Degree Day), or falls above (in the case of cooling, see Cooling Degree Day) an assumed base temperature, normally taken as 18.333°C (65°F), unless otherwise stated.  One degree day is counted for each degree below (for heating) or above (in the case of cooling) the base, for each calendar day on which the temperature goes below or above the base.

The product of one (1) hour, and usually the number of degrees Fahrenheit the hourly mean temperature is above a base point (usually 18.333°C / 65°F); used in roughly estimating or measuring the cooling load in cases where processes heat, heat from building occupants, and humidity are relatively unimportant compared to the dry-bulb temperature.

A device for reducing the level of humidity in a room or home.

Digital Input