A chilled beam system was employed for this building.  This system, along with zoned air handling units running at low coil face velocities and a low pressure drop ductwork design provided considerable energy efficiency and minimized reheat within the building.  The chilled beams being primarily a hydronic system, delivered heating and cooling at the point of use.  A 70% reduction in total fan CFM (compared to a conventional all-air HVAC system) was achieved while still meeting LEED Energy & Atmosphere Credit 2 (ventilation rates at 30% greater than ASHRAE 62.1).  Fan energy was thus reduced considerably, with a small penalty in pump energy.  The chilled beam system also provided the capability of reducing the building height by three feet and reducing the shaft footprint by 75% compared to the requirements of a traditional VAV system.  The project participated in the statewide Savings By Design utility incentive program, which contributed $192,000 in owner incentives for energy efficient design.

Ultimately, the building was projected to perform 35.4% better than the minimum requirements of the 2005 California Energy Code, and 35.1% better (based on energy consumption) than the Baseline Building reported under LEED Energy & Atmosphere Credit 1.  Metered data shows that as a result of the implemented energy-saving strategies, the building is performing over 55% better than the LEED Baseline Building.  After our evaluation, it is our opinion that the ability of DOE-2.1E to model the operation of a chilled beam system is likely to be the major difference in modeled versus actual savings.

Because the chilled beam system operates close to the fresh air requirements for occupancy, this allowed the design to be based on 100% outside air.  Being a healthcare facility, this is particularly important because it can contribute to improved infection control.  The 100% outdoor air configuration also makes it very easy to ensure adequate ventilation of the building at all times, resulting in increased comfort for the staff and patients.  The north waiting areas are fitted with operable windows, which allow the users to connect with the outdoor environment. 

Chilled beam HVAC systems are relatively unfamiliar to most building owners in the Unites States, and, until recently, were used more widely in Europe and Australia.  For this reason, it took some convincing of the clients that this system could be reliably delivered, and that the project could be delivered on time and on budget.  The benefits outweighed the negatives, however, and areas of concern were addressed through meetings with bidders, the use of highly detailed installation methods in the Bid Documents, and Contractor pricing during design.  Energy efficiency, thermal comfort, and indoor air quality won out over risk management concerns.  It was a worthy effort, as the chilled beams proved to be more energy efficient and cost effective than alternative solutions. 

The system also applies the selected chilled beams at the lower end of their operating pressure range.  All chilled beam selections were made at 0.25” WG or less, which is far less than the industry average of 0.5” WG through the beams. 

Occupied in 2010, the building has operated without any issues, and has not required any unusual maintenance.  The chilled beams operate with no moving parts or filters, and are very easily maintained.  The chilled beams generally need only basic cleaning with an industrial vacuum to clean the coils; the frequency of cleaning is expected to be no more than once per two years.

Use of the chilled beam system resulted in many cost benefits.  The floor-to-floor height was able to be reduced three feet, resulting in significant first cost savings.  The fact that over 50% of the zone level cooling is met at the zone level virtually eliminates reheat, which is prevalent in systems where minimum air changes for infection control are used.  Elimination of reheat energy is a significant contribution to the overall energy efficiency of the system.  The system also reduces energy transport costs, as pumping water is a more efficient means of heating and cooling than blowing air, thus further reducing energy costs.  The envelope’s high window-to-wall ratio (42%) allowed for plenty of natural day light to be provided, which along with an efficient lighting design (the building has an overall installed lighting power density of 0.98 watts per square foot) resulted in high electricity savings.  The chilled beam system was initially thought to be unfeasible due to project budget constraints.  Thorough analysis of the chilled beam design as well as alternate designs proved that the system could be delivered on budget when all of the possible cost savings were properly factored in.  With the first cost problem solved, the projected performance of the chilled beam system made the cost effective choice painfully obvious.

The Health & Wellness Center is pursuing LEED Gold certification.  The level of energy efficiency is particularly notable, given the fact that the building taps into the University’s campus steam and chilled water system, which means that chiller and boiler performance has virtually no contribution to the projected energy efficiency.  The chilled beam system must be mentioned here again, as it was the key component to reducing energy consumption through efficient heating and cooling methods.  The building’s use of natural day lighting, along with an efficient lighting design, resulted in high electricity savings as well as contributing all of the Evidence Based Design benefits of daylight and views in a medical facility. The reduction in building height saved a considerable amount in materials costs and environmental impacts material mining, fabrication and transportation.  The tremendous reduction in ventilation rate reduced the size of the air handling equipment, reducing the building’s structural requirements. The Carbon Dioxide Equivalent (CO2e) emissions of the building total 473 metric tons of CO2e/year compared to 872 metric tons of CO2e/year based on the ASHRAE 90.1-2004 Standard building; a 46% reduction in emissions.

The following credits have already been awarded by the GBCI towards final LEED certification of the project:
SSc7.1                     Heat Island Effect: Non-Roof
SSc7.2                     Heat Island Effect: Roof
EAp2                        Fundamental Commissioning
EQp1                       Minimum IAQ Performance
EQc2                        Increased Ventilation
EQc3.1                     Construction IAQ Management Plan: During Construction
EQc3.2                     Construction IAQ Management Plan: Before Occupancy
EQc4.1                     Low-Emitting Materials: Adhesives and Sealants
EQc5                        Indoor Chemical & Pollutant Source Control
EQc6.1                     Controllability of Systems: Lighting
EQc7.1                     Thermal Comfort: Design