Question: For most building design projects, the architectural trade tends to be the consultant (i.e., the lead consultant in the project) who hires the mechanical trade as a sub consultant on the project. In some cases, the mechanical engineering sub consultant has expertise in the design of ductwork to transport air for the purposes of heating and/or cooling an occupied space. A section of a second floor tenant plan of an office space has been designed and presented by an architect.

For the offices shown in the plan (complete with the occupant and work function), the architect has requested that the design temperature in each room be 75?F. If an air distribution system was used to heat the spaces, the following table shows the total amount of air that would be required. The exit temperature of the air from the diffusers would be 110?F in order to ensure the indoor design temperature under winter conditions.

However, instead of an air distribution system, the client has requested that a finned-tube heating system, complete with a dedicated condensing boiler be designed and installed. Comment on any trade-offs between boiler efficiency and heater lengths. Further Information: The length of a standard door is 3 ft.