7/28/2019 Casestudy14 CISCO-Custom AHU

1/2

Cisco Systems, of San Jose, CA, the w orld leader in netw orking for the Internet, w as rapidly expand-ing its corporate off ices. Their Site 4 location w as adding 19 new buildings betw een January 1998and M ay 1999, w hile Site 5 w ould add five in 2000. Containing costs, both in construction expensesand building operation, was a major project consideration. Cisco was looking for cost-effective qualityHVAC systems that w ould deliver reliable performance. Quiet system operation w as a key require-ment, particularly for employees w orking in close proximit y to t he buildings HVAC equipment.

W hile early buildings on Ciscos campus used packaged air conditioning unit s, chilled w ater systemswith air handlers were chosen for the new buildings for more economical operation and flexibility forexpansion. Racan-Carrier saved Cisco $1.2 mil lion in construct ion costs $50,000 per buildi ng bycustom designing air handling units so quiet that the need for ductw ork sound attenuators w as elimi-nated. Using four air handling units per building instead of one large unit simplified installat ion, asthe larger units w ould have been shipped in pieces, requiring costly reassembly. It also eliminated t heleaks that had plagued other Cisco buildings using a competit ors large rooftop air handling unit.

CustomAir Handling Design and Installation

Saves Cisco Systems $1.2 Million

The superior acoustic design properties of Carriers air handlers eliminat ed the need for soundattenuation saving $1.2 mil l ion dollars in construction costs.

Case Study Cisco SystemsCase Study Cisco Systems

AIRSIDE/APPLIED/CONTROLS/SERVICE/SPECIAL SOLUTION/TOTAL SYSTEM/UNITARY

EDUCATION/HEALTH CARE/LODGING/MANUFACTURING/ OFFICEBUILDING / RETAIL/SPECIAL

Project Objectives

Solution

Carriers solution deliveredimpressive sound levels ofNC=3538 vs. competitorsestimated levels ofNC=4042.

7/28/2019 Casestudy14 CISCO-Custom AHU

2/2

Case Study Cisco Systems continued

Cisco Systems w orld headquarters is located in San Jose, California. The multi-bil l ion-dollar company hasexpanded its physical space steadily since the mid-1990s to accommodate its explosive growth. Betw eenJanuary 1998 and April 2000, they added a total of 24 buildings to Sites 4 and 5.

Buildings on the Cisco campus range from three to f ive stories. Some existing buildings used a single airhandling unit on the roof to cool the entire building. These large units had to be shipped and installed inpieces. Not only w as the reassembly diff icult and costly, but it sometimes resulted in leaky equipment.The leaks cost Cisco in repair charges and also caused the equipment t o lose performance, lowering ef fi-ciency and wasting energy dollars. W ith the large number of new buildings being constructed, Cisco engi-neers want ed cost competit ive equipment; streamlined installation; and long-term, reliable performance.

Racan-Carrier emerged wit h a creative design solution. Instead of using one large air-handling unit for eachbuilding, the team proposed using four smaller custom units wi th the same combined total CFM . This con-cept provided several benefits. First, units could be shipped and installed in one piece, greatly simplifyingthe installation process and virtually eliminating the potential for leaks. Second, Racan-Carrier designedthe units using internal w all baffles that reduced the sound levels at intake and discharge, making the unitssignif icantly quieter than any competitor version. In fact, the systems w ere so quiet, they eliminatedCiscos need to purchase any sound attenuators for the ductw ork. This saved the company an impressive$50,000 per building adding up to w ell over a mil l ion dollars in construction cost savings, in addition tothe air handler installation savings. Sound levels on the buildings top floors are NC=35 and on other f loors,NC=38 approximately 15% quieter than the competit ion.

Early buildings at the headquarters used packaged units, said M ichael Lavazza, Cisco manager of mainte-nance operations. As w e expanded, w e decided to go to a built-up chil led water system, which created

the need for air handlers. It w as an economic decision. It s a lot cheaper to cool the buildings using thatkind of design. Plus, it s more versati le for expansion. If we w ant to install additional labs, w e have achil led w ater header system throughout each building so we can just tap off of that to f an coil units orcomputer room air handler units. It was a tw o-fold approach.

Both the project engineer and Ciscos manager of maintenance operations were extremely happy wit h theresulting performance of Site 4s new air handling systems. So happy, in fact, that Racan-Carrier wasselected to design air handlers for f ive buildings at Site 5. [Cisco] facil i t ies have the best of everything,said Ravi M aharaj, Alpha Tech consulting engineer, so w hy not have the best in air conditioning as wel l?

Project Synopsis

Cisco does quality w orkand their off ices reflect

that. Their facilities havethe best of everything, so

w hy not have the best inair condit ioning as w ell?

Ravi M aharaj,consulting engin eer,Alf a Tech Consultin g

Engineers

2000 Carri er Corpo rat ion 08/ 00 811 -10 008

For more i nformation, cont act your nearest Carrier Representative, call 1.800.CARRIER or visit our w eb site at www.carrier.com

Project Summary

Location: San Jose , CA

Project Type:New construct ion

Building Type/Size: Glass andEifs f ront, steel construction;three to f ive stories; Site 4: 19buildings, totaling 3.3 mil l ion sq.ft.; Site 5: f ive buildings,1.5 mil l ion sq. ft.

Building Usage: Offices,conference rooms, computer

testing laboratories

Objectives: To install quiet,durable, cost-effective airhandling equipment

Major Decision Drivers:Cost; system design; reducedsound level

Design Considerations:M ult iple smal ler uni ts were

used per building so unitscould be shipped and installedin one piece

HVAC Equipment: 76 air han-dling units, ranging from 55,000CFM to 95,000 CFM

Unique Features: Air handlersdesigned to eliminate need forductw ork sound attenuators

Project Cost Range:M ore than $5 mi l lion

Installation Date: 1998 2000

Consulting Engineer:Alfa Tech Consulting Engineers

Contractor: Air Systems, Inc.

AIRSIDE /APPLIED/CONTROLS/SERVICE/SPECIAL SOLUTION/TOTAL SYSTEM/UNITARY

EDUCATION/HEALTH CARE/LODGING/MANUFACTURING/ OFFICEBUILDING /RETAIL/SPECIAL