A method of assembling a fan wheel comprising: forming a first wheel portion including a first plurality of impeller blades and a first circular connector; forming a second wheel portion including a second plurality of impeller blades and a second circular connector; affixing an end of each of the first plurality of impeller blades to a first surface of a support ring; affixing an end of each of the second plurality of impeller blades to a second surface of the support ring; and directly coupling the first circular connector and the second circular connector to one another; wherein affixing the end of the first plurality of impeller blades to the first surface of the support ring includes positioning the ends of the first plurality of impeller blades at a plurality of blade receiving areas of the first surface of the support ring; characterised in that each of the plurality of blade receiving areas includes a land and at least one groove (152,154) adjacent the land, and positioning the ends of the first plurality of impeller blades at the plurality of blade receiving areas of the first surface further comprises positioning the ends of the first plurality of impeller blades in direct contact with the plurality of lands; wherein affixing the end of each of the first plurality of impeller blades to the first surface of the support ring further comprises welding the ends to the plurality of blade receiving areas of the first surface of the support ring; wherein welding the ends to the plurality of blade receiving areas of the first surface of the support ring further comprises welding the ends of the first plurality of impeller blades to the plurality of lands; wherein welding the ends of the first plurality of impeller blades to the plurality of lands displaces a portion of material of the lands into the at least one groove (152,154); wherein each of the first and second circular connectors (130, 132) include a raised surface and a first and second groove (182, 184) disposed on opposing sides of the raised surface; and wherein directly coupling the first circular connector and the second circular connector to one another comprises applying heat to melt the raised surfaces together, the melted material flowing from the raised surfaces into one or both of the first and second grooves (182, 184). forming a first wheel portion including a first plurality of impeller blades and a first circular connector; forming a second wheel portion including a second plurality of impeller blades and a second circular connector; affixing an end of each of the first plurality of impeller blades to a first surface of a support ring; affixing an end of each of the second plurality of impeller blades to a second surface of the support ring; and directly coupling the first circular connector and the second circular connector to one another; wherein affixing the end of the first plurality of impeller blades to the first surface of the support ring includes positioning the ends of the first plurality of impeller blades at a plurality of blade receiving areas of the first surface of the support ring; characterised in that each of the plurality of blade receiving areas includes a land and at least one groove (152,154) adjacent the land, and positioning the ends of the first plurality of impeller blades at the plurality of blade receiving areas of the first surface further comprises positioning the ends of the first plurality of impeller blades in direct contact with the plurality of lands; wherein affixing the end of each of the first plurality of impeller blades to the first surface of the support ring further comprises welding the ends to the plurality of blade receiving areas of the first surface of the support ring; wherein welding the ends to the plurality of blade receiving areas of the first surface of the support ring further comprises welding the ends of the first plurality of impeller blades to the plurality of lands; wherein welding the ends of the first plurality of impeller blades to the plurality of lands displaces a portion of material of the lands into the at least one groove (152,154); wherein each of the first and second circular connectors (130, 132) include a raised surface and a first and second groove (182, 184) disposed on opposing sides of the raised surface; and wherein directly coupling the first circular connector and the second circular connector to one another comprises applying heat to melt the raised surfaces together, the melted material flowing from the raised surfaces into one or both of the first and second grooves (182, 184).