A heater bank (aka heat bank) usually consists of multiple heating elements, often in a parallel or series configuration, installed into air conditioning ducts.

ACM sheeting was often installed around the elements as insulation and for fire protection.

Multiple units were commonly installed in air conditioning systems within each floor of multi-storey buildings.

The ACM sheeting type used tended to vary depending on local construction practices:

• LDB provided greater resistance to humidity and was favoured in the northern areas of Australia.
• Millboard was more commonly used in southern areas of Australia.
• Common AC sheeting or compressed sheeting may also be encountered in these structures.

The sheeting may be installed as an interior lining within a constructed (metal) duct housing around the element, or as the actual duct housing attached to frames.