A support structure for a rotary regenerative heat exchanger, the support structure comprising: an upper section comprising an upper ring having a first exterior surface, an upper hub and at least three upper spokes (60A, 60B, 60C) each extending between and secured at respective ends thereof to the upper ring and the upper hub; a first rotor assembly support area an upper bearing a lower section configured to be supportable in use by a foundation mounting structure (254, 254A, 254F, 254F', 254H, 254M, 254P, 254Q, 254Q', 254R, 254R') mounted on a foundation, with the lower section being spaced apart from the upper section; and a plurality of support members, each of the plurality of support members being fixedly secured, directly or indirectly, to the upper ring and the lower section thereby creating an annular space between the upper ring and the lower section, the annular space being configured to receive compartments of a rotor assembly; wherein the upper hub, the upper spokes (60A, 60B, 60C) and the support members cooperate to provide rigidity to the support structure such that the support members cooperate to support and transmit the weight of the upper spokes (60A, 60B, 60C), the upper ring and the upper hub to the lower section, characterized in that said first rotor assembly support area is located substantially axially below an upper axial boundary of the upper ring and the upper spokes (60A, 60B, 60C) of the upper section of the support structure; and said upper bearing is disposed in the first rotor assembly support area; wherein at least one of the upper ring and the lower section have an axial spacing defined by the length of each of the plurality of support members. an upper section comprising an upper ring having a first exterior surface, an upper hub and at least three upper spokes (60A, 60B, 60C) each extending between and secured at respective ends thereof to the upper ring and the upper hub; a first rotor assembly support area an upper bearing a lower section configured to be supportable in use by a foundation mounting structure (254, 254A, 254F, 254F', 254H, 254M, 254P, 254Q, 254Q', 254R, 254R') mounted on a foundation, with the lower section being spaced apart from the upper section; and a plurality of support members, each of the plurality of support members being fixedly secured, directly or indirectly, to the upper ring and the lower section thereby creating an annular space between the upper ring and the lower section, the annular space being configured to receive compartments of a rotor assembly; wherein the upper hub, the upper spokes (60A, 60B, 60C) and the support members cooperate to provide rigidity to the support structure such that the support members cooperate to support and transmit the weight of the upper spokes (60A, 60B, 60C), the upper ring and the upper hub to the lower section, characterized in that said first rotor assembly support area is located substantially axially below an upper axial boundary of the upper ring and the upper spokes (60A, 60B, 60C) of the upper section of the support structure; and said upper bearing is disposed in the first rotor assembly support area; wherein at least one of the upper ring and the lower section have an axial spacing defined by the length of each of the plurality of support members.