rcx article-contracting business dec2006

8/6/2019 RCx Article-Contracting Business DEC2006

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Commercial Contracting

R etro -c omm is sio nin g a llo ws y ou r c om p an yto g iv e bu ild in g ow ne rs a s ec on d c ha nc eto 'd o it r ig h t the firs t tim e. I

B Y D IC K S TA R R

hat is retro-commissioning? TheNational Environmental Balanc-ing Bureau (NEBB) definesretro-commissioning as the sys-tematic process by which theowner ensures that a buildingand its systems are optimized to

perform interactively to meet the current opera-tional needs as closely as possible. This may in-clude remodeled design and construction to ac-complish this goal.

That's a pretty straightforward definition, but abetter explanation might be this: For savvy com-mercial contractors, retro-commissioning is a solidniche business. There is a huge market of buildingsthat need it; it's interesting, challenging and satisfy-ing work for your people; and, when done properly,it creates extremely happy and loyal customers.Retro-commissioning gets you out of the cutthroatnew construction market, and allows you to positionyourself as a premier existing building specialist

The Enterprise Corp. posi tioned itself for retro-commissioning as part of our "reengineering" strat-egy in the late 1990s. We went from a new con-struction mode (primarily with building controls) toan existing building contractor. We always had anactive service business, a strong building controlsknowledge, and we've been a NEBB certifiedair/water balance company for some time. Thesecapabilities are fundamental to a specialty contrac-tor performing start-up and commissioning service.

For 20 years (up tintil2001), our company was asignificant building controls contractor/subcontrac-tor. In the building control business, it 's incumbentthat you understand how the entire design and in-stallation of the HVAC system come together.

As a controls contractor, you're much like the"finish carpenter" on a new house. The HVAC sys-tem never functions properly until the control com-www.contractingbusiness.com

ponents are in harmony with the installed HVAChardware. Now superimpose the dynamics of theconstruction industry with its value-engineered de-sign limitations, prime contrac- 1II_--I'!_I!iiIF!I!("iil1 '. " ',: ,.-i\;;;::---------~=;;-iiiill,-tor failures, and project timelineadjustments. It can result in to-tal chaos by the time of ownerturnover- What a perfect recipefor system dysfunction and pay-ment obstacles for all contrac-tors involved.

Within the new constructionworld, we found ourselves cor-recting as many HVAC sins aspossible through the buildingcontrol system. Financial suc-cess was risky because of de-pendence upon the designlinstallation and time-line we inherited. It became increasingly obviousthat this was no way to run a specialty contractingbusiness that requires highly skilled personneland consistent cash flow. That's when we openedthe door to the world of retro-commissioning.

A n E p id e m ic o f D y s f u n c t io n a l S y s t e m sThe number of dysfunctional HVAC systems isscary. It's a virtual epidemic from coast to coast Howdo you know an HVAC system is dysfunctional? If itsuffers from any combination of factors that preventoccupants from being productive and safe due to themechanical-electrical-plumbing systems. It usuallyresults in higher-than-normal energy costs as well.

Let's take a look at a retro-commissioning projectThe Enterprise Corp. recently completed to give youan idea how the concept works in the real world.

The internationally recognized Cleveland ClinicFoundation (CCF) comprises a network of hospi-tals and medical office buildings throughout ourservice area of Northeastern Ohio. One of the

T he c av alr y a rriv es o nth e s c en e: Ente rpr i se'sF ie ld T e c h ni ci anFo r eman , J o e A z ar a,a t F a ir v ie w Ho s p it al.T h e m e d ic a l o ffic eb u ild in g is th eb u ild in g to th e le ft .

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An En te rp r isetechniciano otn ts to o neo f e ig h trefr igerantexpansionv a lv e s t hecompanyreconf igured.

A n ew c on de ns er fa nv ar ia b le f re q ue n cy d ri vea llo ws th e s ys te m's lo wam bie nt c on tro l to s ta geproper ly.

larger facilities within the CCF network isFairview Hospital. Recently, Fairview made a $12million dollar acquisition ofa 53,000 sq.ft.medicaloffice building (MOB) and 765car open-air park-ing garage located adjacent to its campus.A property management firm is responsible for

leasing tenant space in the MOB, while anothercompany operates the garage.Meanwhile, FairviewHospital's operations department is 100%responsi-ble for the MOB infrastructure, including HVAC,plumbing, and electrical.When Frank Simecek, Fairview's director of fa-

cility services, called about this new acquisition,the situation in the MOB sounded dire: doctorswere threatening to move out, there were numer-ous complaints of temperature discomfort, and in-door air quality was poor. It was time for a retro-commissioning.S t e p - b y - S t e pThe first step in a retro-comrnissioning is to find

out what you're working with. In this case, thebuilding's core system consists of two condensingunits which total 175 tons ofcooling (one 75 ton,one 100 ton); a cooling only air handling unit withsupply and return fan variable frequency drives(VFDs), and 65 variable air volume boxes withelectric reheat. The controls are a hybrid configu-ration: a manufacturer's building automation anddirect digital control system (BAS /DDC) integratesthe central equipment, while pneumatic tempera-ture controls power the VAVboxes.Our initial site visit was designed to inspect,

test, evaluate, and listen to the occupants' com-plaints, while also promoting the hospital's initia-tive to fix the problems to everyone's satisfaction.Afterthisfirstphasewas completed, we were able

to centralize the problems around fourmain issues:..A.The space temperature within the building was

64 CONTRACTINGBUSINESS I DECEMBER 2006

unpredictable. Tenants might need a sweater oneday and a bathing suit the next, no matterwhether it was winter or summer...A.The doctors suites were stuffy. Air stagnationwas everywhere...A.Indoor air quality (IAO)was a pressing issue.Some days garage odors permeated the entirebuilding...A.Buildingenergy costs exceeded $3.50 per sq.ft.The International Facility Manager's Association(IFMA) Operat ions and Maintenance Bench-marks 2005 estimates an average healthcare insti-tution's utility costs at $2.28/sq.ft., an averageclinic at $2.06/sq.ft. This facilityfar exceeded anyutility benchmarks the hospital had studied.A F o u r M o n t h P ro c e s sFrom the initial inspection in February 2006,

through the discovery and implementationprocess, it took Enterprise approximately fourmonths to resolve the HVAC system's dysfunc-tions using the retro-commissioning process.Here's how we did it.When we arrived, supply air duct static pressure

of the building's I25-ton air handling system wasset at and operating at 2.5-in. w.c. The industrystandard for this type ofsystem is 1.5-in. w.c.This over-pressurization of the supply ductwork

was placing undue stress on the 75-hp. supply fanand its associated ductwork. This also contributedto the building's high electrical energy costs. Ourexperience with systems that are set to run at ex-cessive static pressure is that the higher set pointconceals the real problems that are present.Our first step was to lower the staticpressure set-

point from 2.5-in. w.c. to 1.5-in. W.c.to see whatwould happen. Immediatelythere was tenant falloutof "it's too hot." This feedback occurred on a 38Foutside air temperature day in early March. Whenwe accessed the complaining zones, we found theirVAVboxes (remember, the BASonly read the cen-tralsystems,not the zones)with any or all ofthe fol-lowing problems: missing damper actuators, spacethermostats loose on the wall, disconnected pneu-matic control lines, and failedcomponents.The most prominent complaints were in the pe-

rimeter suites (about one-third of the building),where the air was stale and musty and return airwas non-existent. After researching the originaldrawings of record, we learned that somewhereduring the build-out of this five-story facility, re-turn air was stubbed at the return air risers andnever run out to the perimeter zones.Toprovide proper return paths for these SUites,

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we used a reverse engineering approach to size and locate thenew return air openings.The return air system is an often over-looked component ofa healthy and properly functioning HVAC system. Providing a

path for the building air to get back to the HVACequipment isas important as the supply air that heats and cools the building.We then created all new return air openings during early

morning hours to reduce impact on tenant activity and comfort.Resultswere immediately feltas return air openings were cut in.Previouslystagnant areasnow had proper air movement.When the occupants felt the results ofour work, they were

immediately convinced the hospital was serious about makingthis building a productive facility.Another issue found during our discovery phase was that

both supply and return VFDswere operating from the samestatic pressure signal. Minimum industry standards mandatethe return fan track at a speed 10% less than the supply. This"as found" condition resulted in the return fan moving exces-sive amounts ofair, which caused a building negative pressurecondition and hallway draftiness.This was most noticeable in every floor's elevator lobby.

Each floor lobby was connected to one of the six level open-airgarage doors, and negative pressure presented a wind tunnelofair, dirt, and odors that permeated each floor's environmentwhenever any garage access door was opened.This also meant the lobbies were cold in the winter and

hot in the summer. We fixed this condition by allowing theexhaust fan to track correctly with the supply.When we accessed the building automation/DDC system,the programming was a mess. We corrected many control is-

sues, with one ofthe most major being revising the existing se-quence byletting the return air fan be controlled through build-ing static. This was a win-win modification, because now thereturn fan speeds up onlywhen required, which means electriccosts are lowered.When the air conditioning was activated, we found com-

pressors short-cycling due to refrigerant flood back. The ex-pansion valves were set improperly, and the hot gas bypasswas incorrect. Furthermore, the sensing bulbs were alsomounted in a poor location. They were relocated to achieveproper superheat control.As a further refinement, we also installed a separate con-denser fan VFD to the lead 50-ton unit. This ensures reliable

hot gas to aid capacity control. It also minimizes prematurecompressor failures.And what a surprise it was when we found the global DDC

outside air temperature and humidity sensors located in thebathroom and AHUexhaust ducts. Depending upon wind con-ditions, one of the two exhaust temperatures would alwayshave a negative effect on the building control sequence.T u r n i n g O v e r a F u n c t i o n a l S y s te mWith each day on Site,we continued to make improvements

to the building mechanical and control systems (both pneu-www.contractingbusiness.com

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Commercial Contracting

matte and DDC). Work included decluttering 120V controlwiring between the condensing units and the central equip-men t room on the fifth floor, and also reconfiguring theowner's front end building automation system.At the owner turnover

meeting, Fairview's staffwas given final submittalinformation that includeda pictorial of the correc-tion process. Similarly, as-built drawings were alsoincluded, complete withsequence of operation. En te rp ri se r elo c ate d t he g lo b alTrue to the retro-com- o uts id e a ir te m pe ra tu re a ndmissioningmodel, the hos- hum id it y s e ns o rs to u ti li ze o u ts id epital staffwas shown how a ir fo r 'free ' coo l ing.to keep the HVACsystem functional. During a training sessionwith the hospital's maintenance personnel, we reviewed and dis-tributed submittal booklets that described the retro-commission-ingwork we had done, includingthe revisedmechanical and con-trol schematics and new return air openings.A G o o d I n v e s tm e n t

Fairview's investment to diagnose and repair their dysfunc-tional HVACsystem, document the results, and train their per-sonnel was approximately $2/sq.ft. Was this a good invest-ment for them? Let's ask.

Paul Slebodnik, Fairview Hospital's vice president of facili-ties, sent over one unsolicited e-mail during the peak ofcoolingseason which read, "Dick, / have to tell you that we are veryhappy with the wor k your t ec hn ic ia ns are doing. / cannot be-li eve ho w th e p revious contractor thought they wer e doing agood job. I'm certain the tenants will be ve ry a pp re cia tiv e. Iknow that w e are. "

During the fall changeover season, Frank Simecek wrote aringing endorsement to the incumbent property manager thatread, in part, "I just recently had E nterprise do the M OB next tothe ho spital and redo the whole sys tem that {the previo us com-pa ny} used to m snege. I am com plaint free now sin ce th ey d id a llthe w ork to get the system running properly. I j ust thought I'dshoot you a note to tell you wha t a great com pa ny th ey are.The y' re very professio nal and they get the job done rig ht . "Retro-commissioning: it's good for your company, and it'sgood foryou customers. Any further questions?

rcx article-contracting business dec2006

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