case Study 5 Houston Center

The following article was published in High Performing Buildings, Winter 2009. ©Copyright 2009 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. It is presented for educational purposes only. This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. After decades of virtually no new construc- Building At a Glance tion, downtown Houston is experiencing a Building Name 5 Houston Center Location 1401 McKinney Street, revitalization. 5 Houston Center, owned Houston Size 580,875 square feet by Wells Real Estate Funds, is a 27-story, Completed september 2002 5 Use office 580,875-square-foot Class-A office Distinctions Building of the Year in 2007 by the Houston Building Owners and Houston tower on McKinney Street. Completed in Managers Association September 2002, the property is one of five Original design Team

multitenant towers built in the Houston Architect HKS General Contractor Beck central business district since 2000. Wells’ Mechanical Engineer HLM Design Center Civil/Structural Engineer Walter P. Moore portfolios include 113 buildings, with more Lighting Consultant BOS Lighting Elevator Consultant than 23 million square feet of space, across Persohn/Hahn Associates Landscape Architect 27 states and the District of Columbia. The Office of James Burnet Parking Consultant Walker Parking Consultants A Property Designed tive maintenance and tenant work order system. With all building Previous Owner/Developer With Tenants in Mind Crescent Real Estate Equities Designed by HKS, Inc., the lobby equipment logged into the system, consists of brushed stainless steel along with corresponding mainte- columns with grey granite and white nance and inspection tasks, the Present Owner/ marble floors. Its exterior facade of maintenance team is notified via Management reflective insulated glass and alumi- wireless device as each task becomes num curtain wall system is enhanced due. Tenants also can log on to a Web Wells Real Estate Funds REIT II by precast architectural accents. site and use a simple menu interface

Throughout the interior, imported to request maintenance, repair, and Local Wells Real Estate Funds marbles and granites, along with janitorial services, with requests dis- Management Team mahogany paneled walls, highlight patched quickly to an appropriate General Manager rob Nelson the property’s aesthetic quality. staff member. Because the system Operations Manager lubie Martin II resides on the provider’s servers, it is Assistant Property Manager Kelly Blevins Maintenance System Focuses essentially maintenance-free, allow- Taking Care of Tenants Administrative Assistant ila Fontenot On Tenant Convenience ing us to focus on our core business

By Lubie Martin II Proper maintenance and responsive- rather than time consuming data ness to tenant requests are important backups and software maintenance to maintaining efficient operations. issues that would ordinarily be Wells installed an electronic preven- required by our staff. The design features of 5 Houston Center contribute to a decreased electricity consumption of 8% when compared 38 High Performing Buildingsto similar propertiesWinter 2009 in the Houston and Dallas markets. Winter 2009 High Performing Buildings 39 A commitment to service also Tenant Comfort Meets features because of its recent means cost savings for tenants. For Energy-Saving Features construction. example, by partnering with a key 5 Houston Center includes many However, we continue to raise the lighting supplier for all its buildings, leading conservation features that bar for water and electricity savings Wells recently identified lightbulbs are exemplary of today’s approach to and have many projects in the pipe- that were more efficient — and more the environment. We were fortunate line that will make our operations than 35% cheaper — than through a that the building already included even better. We’re in the beginning previous supplier. many state-of-the-art energy-saving stages of pursuing LEED-EB O&M certification, and a number of con- servation projects are in the works. According to assistant property manager Kelly Blevins, who has spearheaded the kickoff of our recent recycling program, “We estimate that we have reduced building waste taken to the landfill by approxi- mately 50% to 60%. Several tenants formally requested a recycling pro- gram and we were pleased to kick off a program with such immediate success. Waste taken to the recycling center continues to increase as we work with tenants to educate their employees.” Blevins has also teamed A lesson learned: the oculus lighting fixture in the lobby is attractive, but the lamps are challenging to replace. The future up with our janitorial provider to strategy is to replace the fixture with a longer-lasting and more energy-efficient one. transition to using LEED-approved cleaning chemicals. The building features innova- for off-site monitoring, schedule When an air-handling unit (AHU) controls networked to the BMS. Each tive heating and cooling features changes, or necessary adjustments. starts or stops, the system acti- terminal box has an electronic ther- designed to maximize tenant comfort This convenient feature means that vates the chiller control. mostat that can vary the temperature while achieving optimal efficiency. authorized personnel do not have to Variable speed drives on the air in its immediate geographical area be physically on site to make adjust- handlers allow the system to supply and allow for greater control in meet- Flexible Centralized Control System ments to HVAC settings. the exact amount of cooling needed ing tenants’ comfort needs. 5 Houston Center uses a building Another service feature allows ten- to maintain comfort, yet can back off Other floors in the building, includ- management system (BMS) to give ants to conveniently call to schedule on the required fan motor horsepower ing areas that don’t contain usable operators an easy-to-use interface after-hours air conditioning. The system when full capacity is not required. By tenant space, are controlled and for tracking and adjusting building tracks the additional use and generates managing and reducing the amount of scheduled by the BMS. The garage systems from the convenience of a monthly report for billing purposes. AHU horsepower and chiller capacity takes up the basement floor through a single workstation. The system’s required, the VAV system minimizes Floor 8, except for Floors 1 and 3, graphical interface allows the opera- Optimizing Comfort and Economy wasted energy from running excess which contain the building’s lobby tor to easily review the status of the The air-conditioning system incor- air-conditioning capacity. areas and some tenant space. The HVAC equipment, perform schedul- porates variable air volume (VAV ) BMS maintains temperature setpoints ing activities, and respond to alarms. technology controlled by the BMS, Meeting Tenant Comfort Needs in these areas. The garage elevator The system allows operators and which modulates the electronic The Tower floors (Floors 9 through lobbies are air conditioned through

The 27-story, Class-A, 5 Houston Center uses an electronic preventive maintenance service personnel to access the con- chilled water valve to maintain the 27) have an average of 31 terminal small fan coil units with two-position and tenant work order system. The maintenance team is notified via wireless trol workstation remotely via modem leaving air temperature setpoint. boxes per floor, each with electronic chilled water valves. The lobby and device as each maintenance and inspection task becomes due. Tenants request maintenance, repair, and janitorial services online using the same system. 40 High Performing Buildings Winter 2009 Winter 2009 High Performing Buildings 41 tenant space are air conditioned tem’s chiller controls. The BMS mon- systems and to provide thermal insu- superior energy efficiency that identi- by several multizone AHUs with itors the temperature of chilled water lation and sound attenuation for the fies the building as one of the most electronic modulating chilled water leaving and entering the system to interior of AHUs. However, these efficient in the nation. Commercial valves and staged electric heat. determine cooling load. The sys- porous surfaces provide favorable buildings that earn the ENERGY STAR tem can then stage or automatically conditions for microbiological growth use an average of 40% less energy than Chiller Control Minimizes sequence the chillers on and off to when they become damp and acti- typical buildings. Energy Consumption meet cooling load demand. By add- vate any dirt that may have become By achieving this designation, we A direct digital control system ing or subtracting chillers from the lodged in the insulation. The build- have demonstrated our commitment orchestrates the air-conditioning sys- run sequence as the load changes, ing’s systems are designed to mini- to environmental stewardship while the system optimizes the number mize the exposure of conditioned also lowering our energy costs. We of chillers required to meet the air to porous insulation surfaces. last scored an energy performance Electricity Use building’s actual cooling load while This, combined with routine main- rating of 86 out of a possible 100. minimizing the central plant’s energy tenance of the AHUs and air filters, The building’s management tracks Month kWh* consumption. This feature allows for enhances indoor air quality for monthly electrical costs with the adjustments due to occupancy and building occupants. ENERGY STAR Portfolio Manager, October 2007 1,096,623 weather and determines the most 5 Houston Center’s AHUs feature including any tenant submeters. 5 Houston Center has three chillers. Running a minimal number of chillers reduces efficient time to start cooling indi- double-wall construction that encases Data are used to compare the build- operating costs. November 2007 1,055,106 vidual floors to achieve a comfortable the insulation between the inner and ing’s energy consumption with simi-

December 2007 991,490 temperature at occupancy time. outer casing, taking the insulation lar buildings and provide a rating. 5 Houston Center has three chill- out of the airstream and providing a With the support of major tenant the three-lamp fixture using 40 watt that use 1.6 gallons and 1 gallon January 2008 1,097,593 ers: one 300-ton unit and two smooth interior surface that is easily Ernst & Young, Wells is also pursu- T-12 lamps. In the case of 5 Houston per flush, respectively. To save even 800-ton units. Running a minimal cleaned during routine maintenance. ing LEED-EB O&M certification for Center, energy-efficient T-8 fixtures more water, building management is February 2008 1,120,435 number of chillers reduces operat- The air is distributed to the terminal 5 Houston Center. were part of the original construction exploring using 0.5 gpm aerators on ing costs. The 300-ton unit is used boxes through externally insulated and use energy-efficient T-8 lamps all sink faucets instead of the exist- March 2008 1,071,678 during low cooling load conditions to sheet metal ductwork that prevents Other Energy-Efficient that consume 30% less energy than ing 2.2 gpm units. We estimate this further enhance energy savings. conditioned air from coming into Features the T-12 fixtures. project to save 129,000 gallons of April 2008 1,137,318 contact with fiberglass insulation. In Wells has a national purchasing water and sewer per year, and the

May 2008 1,078,333 A Breath of Fresh Air addition, the AHU condensate drain Efficient Window Construction agreement with supplier Regency resulting savings to pay for the retro- Fresh air is brought into the building pans are sloped in two planes to pro- Double-pane insulated vision glass Lighting, which includes a cross- fit in approximately six months. June 2008 1,144,501 to ensure that indoor pollutants are mote positive drainage of condensate with high performance reflective coat- over provision to buy new, low- diluted via an outside air-handling water, which eliminates another chal- ing is used throughout the building, wattage lamps rather than older An Attractive, Yet Practical July 2008 1,233,870 unit. This unit filters and precondi- lenge to indoor air quality. further reducing the heating and cool- technology lamps, when building Roof Cover tions the outside air according to the ing energy load. According to the man- staff places an order. This pro- The mechanical penthouses and cool- August 2008 1,256,748 season, using heating and cooling Energy Efficiency ufacturer, the vision glass has a rela- cess is seamless, making it easy ing tower are located on the roof and coils. The outside air intake system 5 Houston Center initially earned tive heat gain of only 59 Btu/h/square to upgrade lighting as technology covered by an aesthetically pleasing September 2008 1,251,101 is designed to deliver 70,000 cfm of the U.S. Environmental Protection foot, compared to 169 for the typical continues to change. For example, mechanical screen that serves as a fresh air to the building, equating to Agency’s ENERGY STAR® designation 1-in. double-pane clear window. when a building maintenance per- prominent identifying feature of the Total kWh Consumption 13,534,796 20 cfm per person based on an esti- in 2005 and received the label again son places an order for a typical building. This screen also protects at

Approximate mated maximum occupancy of 3,500 in 2006 and 2007. The EPA’s national Energy-Saving Lighting 32 watt T-8 lamp, the system auto- least half of the roof area from direct 23 kWh/ft2 per year people. (ASHRAE’s estimated maxi- energy performance rating system pro- Building standard lighting fixtures matically crosses over the lamp to sunshine and helps reduce any radi- mum occupancy is seven persons vides a 1 to 100 scale that helps orga- use energy-saving T-8 lamps with a 28 watt T-8 lamp which is 12.5% ant heat gain to the roof’s covered Approximate 79,525 per 1,000 square feet of net nizations assess how efficiently their electronic ballast, and compact fluo- more energy efficient. portion. The resulting reduction in the Btu/ft2/year occupiable space.) buildings use energy relative to similar rescent downlighting is used through- roof’s surface temperature reduces the Historically, porous fiberglass buildings nationwide. A building that out most of the building. Historically, Water-Conserving Plumbing amount of solar heat absorbed into *Gross kWh consumption includes: Tenant submeters insulation matting has been used to scores a rating of 75 or higher is eli- the typical lighting fixture that has All restrooms in the building have the building and lowers the required Garage lighting line the ductwork of air-conditioning gible for the ENERGY STAR, a mark of been used for office space has been water-conserving toilets and urinals cooling load for the 27th floor. Tenant after-hours HVAC request

42 High Performing Buildings Winter 2009 Winter 2009 High Performing Buildings 43 Lessons Learned

Lighting The attractive oculus in the main location also needs consideration during HVAC schedules to ensure that lease lobby uses incandescent downlighting as the construction phase. Several air-handling requirements are met, but also making sure part of the original design. The downside is units placed in the mechanical room require that no rogue schedules have been left in that the lamps are challenging to replace maintenance staff to leave the room and place. We all know that even the most effi- when they burn out due to their height above enter through another door to gain access to cient machine running when it is not needed the main floor. A different lighting technology other side of the AHU to perform preventive wastes energy. We have audited schedules that features long-lasting energy efficient maintenance. Easy access helps ensure that and adjusted where needed to bring the lamps would have made more sense. To the equipment is properly maintained in a schedules in line with lease requirements. work around this issue, we coordinate group time-efficient manner.R elocating the AHU re-lamping with tasks that require lifts such 2 ft in one direction within the room would Education inadequate education often as window and metal refinishing activities have resolved this issue. derails maintenance teams. Examples to reduce the cost of multiple lift rentals. include adjusting airflow dampers to correct In the future we hope to develop a fixture Variable Speed Drives Two of the three a programming issue; improperly entering replacement strategy that incorporates cooling towers were not originally equipped an overtime air schedule so that it isn’t the design intent with long-lasting, energy- with variable speed drives for the motors. automatically deleted after an event; install- efficient lighting fixtures. Since motor horse power has a cube rela- ing a toilet flush valve repair kit (1.6 gallons tionship with fan speed the energy savings per flush) in a urinal that is designed for a 1 Equipment Access The central plant piping would be enhanced. 5 Houston Center plans gallon per flush kit. Maintenance personnel is supported by many pipe stands and has to install VFDs on the remaining two cells, need to ask more questions when a temper- control wiring run along the floor. This contrib- and incorporate their operation into the con- ature complaint occurs: Is a draft the prob- utes to a congested work area, which makes trol scheme. lem? When does the problem occur? Does chiller repairs more time consuming. A better the problem occur with the office door open solution would have been to design piping Retrocommissioning This will play an or closed (indicating a return air problem)? support that was suspended from the ceiling, important role in the near term to ensure Also, verify that the temperature sensor is Advertisement formerly in this space. and route the conduits overhead to provide that systems are operating at peak design. the one that should be in the space. free space to move dollies, carts, and techni- This includes simple steps, several of which cians throughout the plant freely. Equipment have been taken recently, such as auditing

Conclusions that we include partnering with our the fresh air delivery to the build- The many design features of 5 tenants to provide them with energy ing’s occupants based on ASHRAE Houston Center working in con- awareness information that they can standards. We anticipate these two cert with each other contribute to a distribute to their employees. items will reduce annual electri- decreased electricity consumption of Our employees, vendors and cal expenses by approximately 8% when compared to similar prop- corporate initiatives play an impor- $50,000, or an additional 4% of erties in a sampling of 150 buildings tant role as we partner with our our energy expenditure. • in the Houston and Dallas markets resources to not only maintain prepared by our energy consul- the energy conservation we have tant Summit Energy Services. This achieved, but to build upon the About the Author equates to 20 cents per square foot solid foundation that 5 Houston savings. With today’s soaring energy Center has already established. Lubie Martin II is operations manager with Wells Real Estate Funds. He has prices, we must constantly raise the Our near-term plans call for fur- more than 25 years of experience in bar when looking for opportunities ther reducing energy consumption commercial real estate, and holds a to further reduce energy usage. This by retrofitting the two remaining Texas air conditioning contractors’ includes embracing new technolo- cooling tower cells with variable license, BOMI’s Systems Maintenance Administrator® designation, and an gies as they emerge, and using the frequency drives and modifying associate degree in HVAC&R. existing building enhancements to the outside air intake system to their fullest extent. Also, it is critical monitor CO2 levels to optimize

44 High Performing Buildings Winter 2009 Winter 2009 High Performing Buildings 45