Daylight Draws Library Patrons

The north and south sides of the main library space offer large window views which, combined with the skylights, provide ample daylight to the interior areas. Photo: Mark Luthringer

A zero-net-energy library uses skylights to help deliver daylight to interior spaces, creating an environment that makes patrons want to spend more time among the books.

“ H aving beautiful spaces was really important,” explained librarian Sarah Denton, “and a large part of that was having daylight available at the branch.” Denton is the manager for branch and children’s services for City of Berkeley, Berkeley Public Library, West Branch Library, Berkeley, CA. “But also feeling connected to the outside,” Denton said, expressing how brightening the space with natural interior daylight was an improvement over the darker interiors of previous buildings.

The West Branch library is a completely new building, designed to comply with the City of Berkeley’s 2009 Climate Action Plan. According to Neal DeSnoo, with Berkeley’s Energy Program Management team, the Climate Action Plan “sets the ambitious goal of reducing local greenhouse gas emissions by 80% by 2050 and envisions a city where new and existing buildings achieve zero-net-energy consumption through energy efficiency and renewable energy sources.”

To achieve the goal set by the Climate Action Plan, every new building Berkeley constructs needs to be a zero-net-energy building, according to Gerard Lee, an archi

with

The article is part of a collaboration with the Eneref Institute’s Natural Interior Daylight initiative (nid.eneref.org) to encourage use of daylight. Eneref, an independent research and advocacy organization for sustainable development, is located in Doylestown, PA. tect with Harley Ellis Devereaux, San Francisco, whose firm won the bid for the new West Branch library because of their attention to energy-reduction methods. In no small part, Lee credits the quality of the space to the natural interior daylight the design team created—including windows and skylights. “You give somebody a choice between being in a room that has daylight, as opposed to a windowless room with LED lights, they are going to pick the room with daylight,” Lee stated. While the previous library building had large floor-to-ceiling windows, the challenges inherent in natural interior daylighting design were not considered. Eventually the tall windows in the older building were covered with bookshelves stocked with books, blocking out all of the natural light and fading the books. The skylights, which bring in the majority of the

natural interior daylight, were installed in just two days. “It’s absolutely one of the highlights,” exclaimed Denton as she referred to the significant natural light flooding the interior of the library.

Designing a building with natural interior daylight, as opposed to artificial electric lighting, required the Harley Ellis Devereaux architecture team to account for the changing path of the sun as it sweeps across the sky from dawn to dusk. Harley Ellis Devereaux’s Building Simulation studio used a number of sophisticated modeling-software products to position Velux (Velux America Inc., Ft. Mill, SC) skylights “throughout the building to ensure a very even illumination,” Lee said.

The software also predicted the sun’s year-around motion to avoid shade on the rooftop solar thermal collectors (which generate heat) and solar photovoltaic panels (which generate electricity).

Poorly designed daylight systems can add unwanted heat or glare, something Lee was careful to avoid in the design. Despite the added complexities, Lee insists natural interior daylight is worth the extra effort. “In all the buildings I’ve ever designed, they always have had a daylight component, because it just makes sense,” said Lee.

The building uses numerous other sustainable-design technologies. Instead of a large air-handling unit on the roof, the building uses natural ventilation. The breezes that blow in from the San Francisco Bay create a Venturi effect. Storm water runs into special low-flow planters that filter and clean the water before it enters the ground.

The design team positioned the majority of windows on the north side of the building to minimize solar heat gain. Shades also help to minimize any heat gain through the windows. The north and south sides of the main library space offer large window views. On the sunny south side of the building Lee specified deep, recessed trellis windows, which avoid glare by bringing indirect light into the building. On the roof of the building are 30 skylights that give the building a feeling of “lightness and airiness,” according to Sarah Denton. To minimize glare, the skylights are tilted 20 deg. to the north.

Fifteen of the skylights open, allowing fresh air into the building. Those skylights also allow heat to escape during summer months. The air exchange also can rid the building of volatile organic compounds. “Skylights can come in many different kinds of configurations. The best skylights, in my mind, are those that can be vented,” stated Lee. Skylights tend to be at the very top of a building. Hot air rises. “The best way to eliminate hot air is right through your skylights,” explained Lee, who sees venting skylights as a way of “reducing the need for [traditional] heating and cooling.”

While the passive ventilation cools the air during the summer, the skylights and south-facing windows provide passive heating during winter months. Research backs up Lee’s claim. A recent report by Group14 Engineering,

Left. Daylighting contributed to a notable growth in the number of patrons, who also spend more time in the net-zero-energy library. Photo: Harley Ellis Devereaux

Below. The library has 30 skylights, 15 of which open to allow in fresh air from the San Francisco Bay. In summer months, those skylights allow heat to escape from the building. Photo: Harley Ellis Devereaux

Denver, found that “venting skylights will result in energy cost savings” and “indoor air quality is significantly improved when the venting skylights are used, leading to a very quick dilution of predictable indoor contaminant concentrations.”

Naturalight Solar Inc., Santa Rosa, CA, installed the skylights. They coordinated the install with the building-control company to assure that the automatic blind controls would properly communicate with the building’s computer controls. The skylights have built-in augmenting shades and a sensor that detects when to lower shades. Shades can keep the heat out while still letting the right amount of light needed into the building.

All of the skylights use a recently developed Lo Ē³ glass, manufactured by Cardinal Glass Industries Inc., Eden Prairie, MN, that reflects most of the infrared light, while letting in almost all of the visible light. Therefore, the glass substantially reduces the amount of solar radiation that would otherwise enter the building as heat. The glass is also designed to reduce the potential of fading of interior furnishings.

As an added bonus, the Lo Ē³ glass prevents more heat loss during winter months than more common window glass with clear glass or with older low-e coatings. On top of the book stacks, traditional artificial light was employed, focusing all of their light on the book bindings for ease of locating.

The new building achieved the net-zero-energy rating that Berkeley’s Climate Action plan was seeking. The combined energy generated by the rooftop photovoltaic panels and solar thermal collectors is 17.4 kBtu/sq. ft./yr. The same amount of energy is needed by the building load, which includes the task lighting, heating, cooling

pumps, electrical outlets, hot water, and ventilation fans.

“The West Berkeley library is now the model for sustainable building, merging innovation and beauty,” said Neal DeSnoo of Berkeley’s Energy Program Management team. The community agrees. Compared with the older library building, the number of patrons has increased. “We definitely are seeing our usage numbers going up,” claimed Denton. She added that the library has also seen an increase in the amount of time people spend there. “Whereas previously people would sort of come in and grab stuff and go, they are much more likely to spend some time reading or browsing or chatting with people or just sitting and enjoying the space,” explained Denton. “It’s very busy, continuously, from when we open until when we close. Patrons want to be inside of a beautiful interior.” Library employee Amanda Myers agreed and took it one step further, “It’s easy to come to work because it’s a beautiful building.” CBP

Want more information? The resources below are linked on our website at cbpmagazine.com and our digital magazine at cbpmagazine.com/digital/sep2015.

Circle 8 on the Reader Service Card.

Visit the Harley Ellis Devereaux website page devoted to the West Branch library project.

View Herchong Mahone studies on productivity benefi ts of daylighting.

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How Sweet It Is

Modular lighting-control system is feature rich and intuitive.

Under one roof, Sweetwater Sound, Fort Wayne, IN, houses sales offices, a 100,000-sq.-ft. distribution center, four training rooms, three world-class recording studios, a state-ofthe-art performance theatre, game areas, multiple conference rooms, a workout facility, a music academy, and several large gathering areas.

Consequently, there were many different lighting-control needs for the facility. The typical approach to lighting control in such a situation has been to interconnect systems that are designed to control each specific function, i.e. a theatrical system for dimming control, an energy-conserving system for congregational areas, a modular system for office/warehouse areas, and a centralized solution for control of training and conference rooms.

For example, in Sweetwater’s case there was an existing theatrical-control system in the recording studios made by one manufacturer and an energy-based control solution for areas of congregation by another. At a very basic level, Sweetwater had the burden of maintaining two separate software packages for each solution.

To address the drawbacks of such a configuration, Touché Lighting

Control, Fort Wayne, IN, was called in to upgrade the existing lighting-control system.

“Our solution for Sweetwater is not a collection of existing systems, rather it is a solution designed with the criteria of supporting many different applications. The result is a system that runs on one software platform; a solution where coordinated control between varying functions, i.e. energy conservation and theatrical control, is realized; and a solution that provides additional features and benefits because of the built-in coordination between applications,”

Above. Sweetwater Sound houses sales offices, a distribution center, training rooms, recording studio, a performance theatre, game areas, conference rooms, a workout facility, a music academy, and several large gathering areas.

Left. Touché’s multi-button wall stations allow the user to select the number of buttons and the labeling for each button through an intuitive-configuration software interface.

Top. There were many different lightingcontrol needs for the facility. Requirements for the 100,000-sq.-ft. distribution center naturally were quite different from those of performing areas.

Above. Offi ce space for sales operations is another of the areas with specifi c lighting-control requirements at Sweetwater.

Touché president Mike Picco said.

The modularity of Touché’s solution simplified the installation process, reduced operating costs, and provided a foundation for expansion. Its modularity allowed Sweetwater to expand into existing areas with a very low front-end cost and caused minimal impact on the operations of areas currently under control by the system.

Touché’s multi-button wall stations allow the user to select the number of buttons and the labeling for each button through an intuitive-configuration software interface, instead of using engraved plates or stickers to represent the functions.

Sweetwater Studios is an example of the need for redundancy in a lighting-control system. With other systems, if a user interface in one of the recording studios failed, then all operations would cease. This obviously causes major interruptions in the recording rooms. To prevent this scenario from occurring, Touché was able to provide three levels of redundancy to control the lighting at Sweetwater. Control can be handled from any of three connected iPads, a touchscreen computer in the mechanical room that allows all areas to be remotely controlled, and each dimmer can be controlled locally at the relay-dimmer (RD) panel, using the touchscreen interface.

Control logic can become complex, especially when multiple modes of control are implemented in a common area. For example, when occupancy sensors, daylight sensors, override switches, and system schedules are combined to control a common area, the logic behind that level of integration can become daunting. This was avoided at Sweetwater with the use of distributed intelligence on these devices to simplify the interactions between the functions. The lighting company also offers simple methods to integrate other systems with the lighting-control system with the use of interfaces like native BACnet and an RS232 interface module.

Lighting control was simplified at Sweetwater by allowing the end user to configure the system without requiring the system to be programmed. To accomplish this, Touché used a simple press-and-hold technique that’s designed to set scenes on touchscreen computer interfaces. The user simply sets the light levels using intuitive on/off buttons for relays and sliders for dimmers. Next, the user presses and holds the selected scene button to save the scene. All the user has to do is press the same button to retrieve the desired state/scene with no special programming required.

Setting up and calibrating system devices, one of the main challenges in implementing a lighting-control solution, proceeded smoothly at Sweetwater. Installers commented on the lack of DIP switches and dials on Touché’s sensors. Thanks to the automatic calibration capabilities of the sensors, switches and dials are not needed. Calibration is taken a step further by having the sensors continuously calibrate themselves; as environmental conditions change, the sensors automatically adapt.

Standard Cat 5 cabling connects all of the devices. The communication and control power between devices uses this same structure, greatly reducing the learning curve for the installer. In addition, the devices are mounted to industry-standard electrical boxes and integrated with standard device plates, resulting in lower installation costs.

Just as important, the Sweetwater facility benefited from improved functionality. End users are now able to set just the right lighting scene, from the recording studios to the retail area and everywhere in between. CBP

Want more information? The resources below are linked on our website at cbpmagazine.com and our digital magazine at cbpmagazine.com/digital/sep2015.

Circle 7 on the Reader Service Card.

Download a Touché lighting brochure.

Download a catalog. Watch a video on integrating Touché with BACnet.

Watch a video on confi guring a touchscreen switch.

Watch a video on custom interfacing.