Duke Eye Center






Duke Eye Center – Duke University Medical Center


Durham, North Carolina


Off Site Construction – Penthouse Replacement


Project Overview:

EAS was contracted to provide design assistance, off-site construction, shut down planning and installation for a new penthouse to replace two existing penthouses.

EAS was responsible for complete demolition of an existing penthouse and the “gutting” of another penthouse. Total shutdown was for a period of five (5) days over two weekends. The speed of this project could only have been achieved through an EAS Off Site Construction (OSC) approach. A traditional design-bid-construct contract method would have added substantial project cost and trade coordination issues.

Duke’s original plan was for 60 to 90 days of construction — EAS reduced that timeframe to two weekend shut downs.

This is one example of many projects EAS has completed for Duke over the years.

Project Highlights:

1. 80,000 CFM System measuring approximately 66’ x 38’ x 12’ high

2. EAS had the task of removing one penthouse, with AHUs that were installed in 1974 before installation of the new EAS penthouse could start

3. First shutdown commenced about 6:00 PM on a Friday afternoon

4. System start up took place about 6:00 PM on the following Sunday afternoon

5. During the first weekend shutdown, ductwork from the new EAS penthouse ran to the existing penthouse, keeping it operational

6. Second weekend shutdown was for 2 days to demolish the AHUs in the second penthouse that EAS took out of service

7. The job required two (2) 12-hour shifts per day, comprised of 32 men per shift

8. The existing penthouse which had the mechanical equipment removed, was given a new exterior to the match the new penthouse, leaving Duke with a 50’ x 30’ storage building for filters, etc.

9. EAS worked in a design/assist role with IES Engineers, the Consulting Engineer, and RND Architects, the Architectural Consultant

10. EAS provided phasing coordination, feasibility studies and budget development

11. Down time was limited due to good planning, coordination and communication

Technical Details:

Hot Deck / Cold Deck Design to match existing HVAC Scheme

80,000 CFM Cold Deck Supply, using two (2) 75 HP Class III Supply Plenum Fans

58,000 CFM Hot Deck using (1) 100 HP Class III Supply Plenum Fans

Two (2) Return / Relief Air Fans at 36,000 CFM each, Plenum Fans

One (1) Vertical Exhaust Fan

Variable Frequency Drives


Cooling and Reheat Coil banks, 304 Stainless Steel

Relief Air, Return, Bypass, Return Air and Outside Air Dampers

Pre, Intermediate and Final Filters Sections

Schedule 40 chilled water and hot water piping systems with valves and accessories. At the shipping splits, there are flanged or grooved connections for the hot water and chilled water piping