e-News #65: Saving Lives, Saving Energy

June 25, 2009
 
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Saving Lives, Saving Energy: Top Strategies for High- Performance Hospital Design

Ongoing construction and major retrofitting of hospitals in California, driven by aging facilities and the demand for new medical technologies, offers an unprecedented opportunity to dramatically improve the energy performance of healthcare facilities for decades to come.

Operating Room In today's healthcare setting, day-to-day operations are equipment intensive, and correspondingly energy intensive as well.

Designs that reduce energy use and related emissions of pollutants and greenhouse gases - as well as maintain high indoor air quality - can complement the healthcare industry's mission of saving lives. This issue of e-News gives an overview of some of the top energy-saving strategies for new construction of hospital buildings.

Challenges of Hospital Design

Hospitals, in general, are unique and highly specialized buildings that present distinct design challenges for both architects and engineers:

  • Hospitals must operate 24/7, with high demands for cooling, electricity, and hot water.
  • Hospitals require redundancy and emergency backup power at all times, and must remain operational even during natural or other disasters.
  • Very tight controls are required for temperature, humidity, and ventilation, and those requirements often vary among different space types.
  • Precautions must be taken to reduce or eliminate the transmission of infectious diseases through HVAC systems.
  • Day-to-day operations are equipment-intensive, but no efficiency rating systems exist for medical equipment.

Although highly energy intensive, a hospital's energy costs constitute a small percentage of its overall operating budget, so in the past, design for energy efficiency was often overlooked. However, according to the EnergySmart Hospitals Program, every dollar a non-profit hospital saves is equivalent to $20 in generated revenue.

Top Strategies for Energy-Efficient Hospital Design

Chilled Beams

Seismic Safety Regulations Driving Boom in Hospital Construction

Many older hospitals sustained considerable damage as a result of the 1994 Northridge earthquake. In response, the State Legislature enacted SB 1953, which strengthened the state's requirements for seismic safety of hospitals to increase the likelihood that they will be capable of remaining intact and continuing to operate after an earthquake.

According to Office of Statewide Health Planning and Development (OSHPD), the state agency that has jurisdiction over hospital construction, approximately 470 general acute care facilities, including 2,673 hospital buildings, are affected by SB 1953. The requirements of SB 1953 are triggering a boom in the new construction and major retrofits of hospitals across the state.
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The chilled beam is one of the latest innovative cooling technologies to make its way to the U.S. market. The system works by running chilled water through cooling coils located at ceiling level to cool the rising warm air. The cooled air then gently descends to occupant level, providing a cooling effect with minimal air movement and fan power, while providing an unobstructed radiant heat sink above the occupied zone. Chilled beams achieve their cooling effect by convection, using finned elements through which the water is passed between 59°F to 65°F.  This technology is most applicable to interior environments where heat gain in the space (solar radiation, equipment heat, etc) is the primary impetus for determining air flow quantities.

Chilled beams are available in three types: passive chilled beams, active chilled beams, and multi-service chilled beams. Common to each category is a radiator element which provides radiant cooling via circulated cool water. The primary distinction between passive and active chilled beams is the mechanism by which air flow is promoted and how fresh air is introduced into the occupied space. Passive beams utilize natural convection, while active beams offer increased cooling capacity using a primary air supply to induce convection over the elements. Active beams can also be used for heating. The primary air is then supplied to the room through diffusers built into the beam. Multi-service chilled beams can integrate a wide variety of other building services such as lighting, speaker systems, IT systems, fire protection (sprinklers and detectors), and photocells.

In a hospital setting, energy savings are realized through higher supply air temperatures and using chilled beams to cool air locally.  Allowing higher supply air temperatures reduces cooling loads at the central cooling plant, as well as energy required for reheat.  Chilled beams may be an efficient, cost-saving alternative to traditional variable-air-volume (VAV) systems in hospital wards where medical equipment is a significant source of internal heat gains.

Thermal Energy Storage

Thermal energy storage (TES) systems are used to produce large amounts of stored cooling energy, preferably during periods when power plant electrical demand is low and electricity prices are lower as well. A typical TES system will charge a large storage medium such as an ice reservoir during the night, and use the stored energy to meet peak air conditioning and equipment loads during the day. Employing a thermal storage system can thus significantly reduce electricity and cooling costs and can also result in less strain on local electricity infrastructure. Further cost savings can be achieved by downsizing required cooling equipment, as the stored cooling energy will help to reduce or eliminate peak cooling loads. If designed and planned properly, a TES system may result in a less costly cooling and distribution system, which may completely negate the added expense of the TES components. Medical facilities in California are among the building types most well-suited to take advantage of TES systems because of their high demand charges along with their high air conditioning and other cooling loads.

Combined Heat and Power

UCSF Medical Center Pursues LEED Gold

The UCSF Medical Center plans to build a 289-bed integrated hospital complex that will serve children, women, and cancer patients and will target Leadership in Energy and Environmental Design (LEED®) Gold certification.

The first phase of the building at the UCSF Mission Bay campus is expected to be complete in 2014 and will include 50,000 square feet of green roofs intended to serve as therapeutic gardens, each with a unique design to address patient needs and hospital requirements.

Seventy-five percent of patient rooms have been designed such that their orientation allows direct sunlight penetration into the space without glare. Staff workstations have also been designed with daylighting strategies that will provide nearly all patient-care areas with daylight and views to the outdoors.

Other innovative design strategies include reusing cooling tower blow down for irrigation and a heat recovery ventilation system. Indoor air quality will be addressed through a number of efforts including a comprehensive materials assessment as well as delivering 100 percent outside air to all spaces.

The hospital is investigating the feasibility of additional conservation measures for the new complex including photovoltaic panels.
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Combined heat and power (CHP, also known as cogeneration) is the use of a generator, such as a steam turbine, heat engine, microturbine, or fuel cell, to simultaneously produce both electricity and useful heat. Conventional power plants emit the heat created as a byproduct of electricity generation into the environment through cooling towers, as flue gas, or by other means. CHP captures the byproduct heat for domestic or industrial heating purposes, either very close to the generator or for distribution through pipes to meet local heating requirements. Byproduct heat at moderate temperatures (100 to 180°C) can also be used in absorption chillers for cooling. Such a system is sometimes called combined cooling, heating, and power (CCHP) or trigeneration.

CHP is thermodynamically the most efficient use of fuel. In separate production of electricity, some energy must be rejected as waste heat that is given off to the environment, whereas in cogeneration, this excess thermal energy is captured and used, thereby reducing the energy required from other sources to meet heating loads. Depending on the technology used, the efficiency of the system can be raised to 60-80% if supplying heat along with electricity, compared to about 33%, the average efficiency of U.S. fossil-fueled power plants producing electricity only. Hospitals are one of the best cogeneration applications because of their year-round need for hot water or steam. In addition, cogeneration options may help hospitals meet their need for standby generation in the event of a grid outage.

Daylighting

Daylighting, with adequate solar control, can provide substantial energy savings in addition to the numerous other visual and psychological benefits. The intent of daylighting design is to provide a portion or all of the lighting needs of a space with daylight, while maintaining a visual connection with the outdoors for the occupants. Daylighting has the potential to provide significant energy and demand savings, with the latter often coinciding with peak loads. Daylight may be introduced into a building through a variety of approaches such as windows and glazed doors, skylights, clerestories, light shelves, and light tubes, typically used in combination with solar control elements. Daylighting design evaluates the building form, apertures, fenestration, roof, and other building components to determine the best strategy for introducing useable daylight into the spaces, avoiding problematic visual (glare) and thermal (solar gains, night losses) conditions for the occupants. The placement, design and selection of materials for fenestration and any solar control elements are extremely important and can tip the balance between a high-performance and a low-performance building.

Daylighting creates a healthier luminous environment and gives occupants a connection to the outdoors. The variance in daylight levels throughout the day actually helps maintain healthy biological cycles in the body. Daylighting can be supplemented with electrical tasklighting when specific tasks need to be performed. If a constant level of illumination is desired, photo sensors and dimmers may be used that will adjust light levels based on the amount of daylight in the space. Daylighting and views to the outdoors, along with bedside control over lighting and window shades, contributes to a patient's psychological outlook, rate of healing, and quality of stay.

Vegetated Roofs

Resources

American Society for Healthcare Engineering, Visit site >

Energy Design Resources' Design Briefs, e.g., Options & Opportunities, Integrated Building Design, Building Simulation
Visit site >

Green Guide for Health Care Visit site >

Labs for the 21st Century, Visit site >

Office of Statewide Health Planning and Development Visit site >

Utility incentives
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A vegetated or green roof is covered in part, or in full, by a structure that consist of vegetation, soil, a drainage layer, and a high-quality waterproofing membrane that protects the building structure. A green roof provides shading, insulation, thermal mass, and water filtration and thus offers multiple benefits including reduced heating and cooling loads, mitigation of the heat island effect, and lower stormwater rates and volumes.

A vegetated roof has the potential to significantly reduce heat flow through the roof surface caused by solar radiation. As a result, green roofs provide greater savings in hot climates, because green roofs have a greater potential to reduce cooling loads compared to heating loads. In addition, a green roof can dramatically increase the life of a roof membrane by reducing temperature fluctuations. By some estimates, a green roof can last two to three times longer than a conventional roof system.

Beyond the environmental benefits of green roofs, many hospitals are finding that green roofs can serve as an exterior therapeutic environment to reduce stress and promote healing and relaxation for patients.

Incentives & Guidelines for High-Performance Hospital Design

Savings By Design

New healthcare facilities may be eligible for Savings By Design (SBD) incentives for high-performance design. SBD incentives calculations use Title 24 as a baseline, but because hospitals don't have to comply with Title 24, SBD has a special guideline for calculating hospitals' incentives. Website: www.savingsbydesign.com

Green Guide for Healthcare

A best practices guide to healthy and sustainable building design, construction, and operations for the healthcare industry, the Green Guide for Healthcare Version 2.2 was first released in January 2007, after two years of use as a pilot program. The Green Guide uses, with permission, the credit structure of the LEED Green Building Rating System. Unlike LEED, the Green Guide is a self-certifying toolkit that owners and designers can use to guide and evaluate their progress toward high-performance healthcare facilities. Website: www.gghc.org

EnergySmart Hospitals Program

The U.S. Department of Energy has created the EnergySmart Hospitals Program to provide the resources, tools, and strategies that will enable the nation's hospitals to identify clear pathways to cost and energy savings through efficient and renewable energy technology applications for both new and existing facilities. Goals of the program include a reduction of energy use by 20% in existing facilities and by 30% in new construction, in addition to reduced operating costs. Website: www1.eere.energy.gov/buildings/energysmarthospitals

Laboratories for the 21st Century (Labs 21)

This U.S. EPA's voluntary partnership program is dedicated to improving the environmental performance of U.S. laboratories. Although geared to laboratories, it offers design and best practices guides and other resources useful for hospital designers. Website: www.labs21century.gov

 

Training Highlights

California utilities offer outstanding educational opportunities that focus on the design, construction and operation of energy efficient buildings. Listed here are a few of the many upcoming classes and events; for complete schedules, visit each utility's website.

Daylighting for Buildings
This seminar covers the planned use of natural light in existing buildings and new building design, and the importance of improved energy efficiency to provide a healthy, productive interior space for building occupants. Architects and designers will learn about design fundamentals, human health, occupant performance and productivity, daylight delivery systems, controls, and design tools.

This course is offered August 4, 2009 in Irwindale.
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Daylighting Controls
This course for architects, energy managers, and other lighting professionals will provide a basic understanding of lamps and ballasts, as well as an overview of energy management strategies and lighting control systems. Topics covered include dimming versus switching scenarios, open and closed-loop systems, equipment selection factors, system verification, and commissioning.

This course is offer September 15, 2009 in Irwindale.
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Energy Saving for Hospitals & Healthcare Facilities
This seminar highlights the strategies and the latest available technology for energy-saving measures in hospitals and healthcare facilities. It examines unique approaches utilizing the building automation systems in compliance with OSHPD requirements to save energy while improving the conditions within a building. Real-world examples for various scenarios will be discussed and presented.

This seminar will be held on July 23, 2009 in San Diego.
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About e-News

Don't miss future issues - to sign up for a free email subscription, please visit our newsletter subscription page. Send letters to the editor, suggestions on topics for future issues, or other comments to the e-News editor via our Comments & Feedback form.

e-News is published by Energy Design Resources (www.energydesignresources.com), an online resource center for information on energy efficiency design practices in California.

Savings By Design (www.savingsbydesign.com) offers design assistance and incentives to design teams and building owners in California to encourage high-performance nonresidential building design and construction.

Energy Design Resources and Savings By Design are funded by California utility customers and administered by Pacific Gas and Electric Company, Sacramento Municipal Utility District, San Diego Gas and Electric, Southern California Edison and Southern California Gas Company, under the auspices of the California Public Utilities Commission.

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