System and apparatus for conditioning of indoor air

A control system comprising:

• a supply input port;
• a load return port;
• a recirculation pump for pumping liquid from a pump input port to a pump output port, the pump input port connected to receive a first portion of liquid flowing from the load return port;
• a junction configured to combine liquid flowing from the pump output port with liquid flowing from the supply input port;
• a load input port configured to receive such combined liquid from the junction;
• a supply return port connected to receive a remaining portion of the liquid flowing from the load return port;
• an actuator to vary a flow rate of liquid between the supply input port and the supply return port;
• a temperature sensor;
• and
• a control module to control the actuator based at least in part on a liquid temperature measured by the temperature sensor,
• wherein
• the control module is configured to receive an ambient temperature in a conditioned space and a setpoint temperature, and to additionally control the actuator based on the setpoint temperature and the ambient temperature,
• the liquid temperature measured by the temperature sensor is a load input temperature of the combined liquid,
• the control module is configured to determine a target liquid temperature for the load input temperature based at least in part on the setpoint temperature and the ambient temperature, and
• the temperature sensor is a first temperature sensor, and the control system further comprises a second temperature sensor to measure a load return temperature of the liquid flowing from the load return port.

A control system, comprising:

• a first supply input port;
• a load return port;
• a first junction to split flow from the load return port into a first portion and a second portion;
• a recirculation pump for pumping liquid from a pump input port to a pump output port, the pump input port configured to receive the first portion from the first junction;
• a first supply return port configured to receive the second portion;
• a second junction to combine flow from the first supply input port and the pump output port;
• a load input port configured to receive such combined flow from the second junction;
• a first actuator to vary a first flow rate of liquid between the first supply input port and the supply return port;
• a temperature sensor;
• and
• a control module to control the first actuator and the pump based at least in part on a liquid temperature measured by the temperature sensor;
• a second supply input port;
• a second supply return port;
• and
• a second actuator connected between the second supply return port and the first junction to vary a second flow rate of liquid between the second supply input port and the second supply return port.

A control system, comprising:

• a supply input port;
• a load return port;
• a first junction to split flow from the load return port into a first portion and a second portion;
• a recirculation pump for pumping liquid from a pump input port to a pump output port, the pump input port configured to receive the first portion from the first junction;
• a supply return port configured to receive the second portion;
• a second junction to combine flow from the supply input port and the pump output port;
• a load input port configured to receive such combined flow from the second junction;
• an actuator to vary a flow rate of liquid between the supply input port and the supply return port;
• a temperature sensor;
• and
• a control module to control the actuator and the pump based at least in part on a liquid temperature measured by the temperature sensor,
• wherein the control module is further configured to (i) receive an ambient temperature in a conditioned space and a setpoint temperature, (ii) determine a target liquid temperature based at least in part on the setpoint temperature and the ambient temperature, (iii) control the actuator based on the target liquid temperature and the liquid temperature measured by the temperature sensor, and (iv) control the recirculation pump based at least in part on an operating mode.