Fresh air plenum module for a fan coil unit

Abstract

A fresh air plenum module (10) for attachment to a fan coil unit (12) for introducing air from an outdoor setting, wherein the fresh air plenum module includes: a first inlet (14) for connection to an outlet (24) of the fan coil unit; a second inlet (16) for connection to an air handling unit; an outlet (18) for discharge of the outdoor air and the conditioned air; and a merging volume (20) in communication with the first inlet, the second inlet and the outlet; in use, a flow of the outdoor air from the second inlet through the merging volume to the outlet generates a pressure gradient which induces a flow of air through the first inlet and into the fresh air plenum module from the fan coil unit.

What is claimed is: 
     
         1 . A fresh air plenum module for attachment to a fan coil unit for introducing air from an outdoor setting, wherein the fresh air plenum module comprises:
 a first inlet for connection to an outlet of the fan coil unit;   a second inlet for connection to an air handling unit;   an outlet for discharge of the outdoor air and the conditioned air; and   a merging volume in communication with the first inlet, the second inlet and the outlet;   wherein, in use, a flow of the outdoor air from the second inlet through the merging volume to the outlet generates a pressure gradient which induces a flow of air through the first inlet and into the fresh air plenum module from the fan coil unit.   
     
     
         2 . A fresh air plenum module as claimed in  claim 1 , wherein the fresh air plenum module comprises at least one nozzle fluidly connected to the second inlet for injecting the outdoor air into the merging volume. 
     
     
         3 . A fresh air plenum module as claimed in  claim 2 , wherein the fresh air plenum module comprises a first plenum compartment connected to the second inlet and configured to supply outdoor air to a first set of one or more nozzles; and a second plenum compartment connected to the second inlet and configured to supply outdoor air to a second set of one or more nozzles. 
     
     
         4 . A fresh air plenum module as claimed in  claim 3 , wherein the first plenum compartment is located on a first internal side of the fresh air plenum module; and the second plenum compartment is located on a second internal side of the fresh air plenum module; wherein the first internal side and the second internal side are in a facing spaced relationship. 
     
     
         5 . A fresh air plenum module as claimed in  claim 3 , wherein the second inlet is configured to divide the outdoor air flow from the air handling unit equally between the first plenum compartment and the second plenum compartment. 
     
     
         6 . A fresh air plenum module as claimed in  claim 3 , wherein the fresh air plenum module is configured to direct more than half of the outdoor airflow from the air handling unit to the first plenum compartment; or the fresh air plenum module is configured to direct more than half of the outdoor airflow from the air handling unit to the second plenum compartment. 
     
     
         7 . A fresh air plenum module as claimed in  claim 3 , wherein a volume of the first plenum compartment is greater than a volume of the second plenum compartment; or the volume of the second plenum compartment is greater than the volume of the first plenum compartment. 
     
     
         8 . A fresh air plenum module as claimed in  claim 3 , wherein the first set of nozzles comprises more nozzles than the second set of nozzles; or wherein the second set of nozzles comprises more nozzles than the first set of nozzles. 
     
     
         9 . A system comprising the fresh air plenum module of  claim 1  and a fan coil unit, wherein the first inlet of the fresh air plenum module is coupled to the outlet of the fan coil unit. 
     
     
         10 . A system as claimed in  claim 9 , comprising an air handling unit, wherein the second inlet of the fresh air plenum module is connected to the outlet of the air handling unit. 
     
     
         11 . A system as claimed in  claim 9 , wherein the fan coil unit has a controller configured to independently operate the coil of the fan coil unit and the fan of the fan coil unit. 
     
     
         12 . A method of installation of a fresh air plenum module or system as claimed in  claim 1 , the method comprising: providing the fresh air plenum module; fitting the first inlet of the fresh air plenum module to the outlet of a fan coil unit; and connecting the second inlet of the fresh air plenum module to the outlet of an air handling system. 
     
     
         13 . A method of operating a system as claimed in  claim 9 , the method comprising operating the system in an induction mode, the induction mode comprising:
 providing outdoor air to the second inlet of the fresh air plenum module;   operating a coil of the fan coil unit; and
 not operating a fan of the fan coil unit;
 wherein the flow of conditioned air through the fan coil unit is induced by the pressure gradient generated by the flow of outdoor air through the fresh air plenum module. 
 
   
     
     
         14 . A method as claimed in  claim 13 , the method comprising operating the system in a boost mode, the boost mode comprising:
 providing outdoor air to the second inlet of the fresh air plenum module;   operating the coil of the fan coil unit; and
 operating the fan of the fan coil unit;
 wherein the flow of conditioned air through the fan coil unit is provided by the pressure gradient generated by the flow of outdoor air through the fresh air plenum module and the operation of the fan. 
 
   
     
     
         15 . A method as claimed in  claim 13 , the method comprising operating the system in an eco mode, the eco mode comprising:
 providing outdoor air to the second inlet of the fresh air plenum module;   not operating the coil of the fan coil unit; and
 not operating the fan of the fan coil unit;
 wherein the pressure gradient generated by the flow of outdoor air through the fresh air plenum module induces a flow of air through the fan coil unit.