Controller for operating a dual duct variable air volume terminal unit of an environmental control system
AssigneeJohnson Controls Technology Company
InventorsJonathan D. West, John E Seem
Life of this patent
Estimating the term…
Abstract
The flow air from a hot air duct and a cold air duct into a zone of a building is controlled in based upon performing a thermal energy balance calculation for the zone. That calculation produces a heat transfer setpoint from which a hot air flow setpoint and a cold air flow setpoint are derived. The hot and cold air flow setpoints respectively control the flow of air through the hot and cold air ducts.
Claims12
A method for controlling flow of fluid from a hot fluid conduit and a cold fluid conduit that environmentally controls a zone of a building, said method comprising:
- performing a thermal energy balance calculation for the zone thereby producing a heat transfer setpoint Qsp, which indicates a desired heat transfer rate;
- in response to the heat transfer setpoint, deriving a hot fluid flow setpoint and a cold fluid flow setpoint which respectively indicate desired flow rates of the hot fluid from the hot fluid conduit and of the cold fluid from the cold fluid conduit;
- controlling flow of hot fluid from the hot fluid conduit in response to the hot fluid flow setpoint;
- and
- controlling flow of cold fluid from the cold fluid conduit in response to the cold fluid flow setpoint.
A method for controlling flow air from a terminal unit which receives air from a hot air duct and a cold air duct and which has an outlet from which air is supplied to a zone of a building, said method comprising:
- sensing a temperature within the zone to produce a sensed temperature value TZONE;
- comparing the sensed temperature value to a temperature setpoint Tsp thereby producing a temperature error signal TE;
- deriving a heat transfer setpoint QSP in response to the temperature error signal;
- determining a first temperature of air received from the hot air duct and a second temperature of air received from the cold air duct;
- deriving a hot air flow setpoint and a cold air flow setpoint in response to the heat transfer setpoint, the first temperature, and the second temperature;
- controlling flow of air from the hot air duct in response to the hot air flow setpoint;
- and
- controlling flow of air from the cold air duct in response to the cold air flow setpoint.
Dependencies are inferred from the claim text.