Tag Archives: lighting

Analysis: Best Practices for Providing Effective Daylight in Mid-Century Modern Structures

DOCOMOMO_OREGON and the Northwest Chapter of the Association for Preservation Technology recently held an Energy Conservation Symposium that explored issues facing mid-century modern buildings: How can modern historic buildings comply with today’s energy conservation standards? Is it possible to maintain the integrity of the historic building materials and aesthetics while also meeting new energy conservation requirements?

At PMA we believe that while challenging, it is possible to maintain the integrity of these historic mid-century modern buildings and meet new energy conservation requirements. In an effort to explore this possibility, we submitted an abstract for the symposium, and Halla Hoffer, AIA, subsequently presented on Best Practices for Providing Effective Daylight in Mid-Century Modern Structures.

BACKGROUND
Effective daylighting can reduce both lighting and cooling loads while improving user comfort, satisfaction, and health. Despite plentiful glass, using daylight in mid-century modern building can be challenging. Glare and uneven light distribution can cause user discomfort and pose challenges to effectively daylighting spaces. Frequently, artificial lighting is used to balance lighting in spaces over lit by the sun, negating any potential energy savings. For existing buildings, the available methods to provide effective daylighting are limited by the existing constructions and configuration. To both preserve existing structures and provide ample daylight a critical question must be answered – what are the best practices for improving daylight in existing buildings? This study provides insight to daylighting existing structures, specifically, how light can be controlled and distributed in mid-century modern buildings with plentiful glazing.

1963 RESIDENTIAL TOWER
This study explores and analyzes how common daylighting strategies can be implemented on existing mid-century modern structures. The study focuses on a sixteen-story 1963 residential tower in Portland, Oregon, and explores how interior reflectivity, interior/exterior light shelves, shading, and glazing can impact daylight availability and distribution. The study looks at a variety of ways each strategy can be implemented and analyzes the results to determine best practices based on daylight distribution/availability, glare, lighting loads, and heating/cooling loads.
on Best Practices for Providing Effective Daylight in Mid-Century Modern Structures

TOOLS USED FOR SPECIFIC ANALYSIS
Emerging tools and technologies provide effective methods of analyzing hundreds of different daylighting simulations. Applications such as Grasshopper and Dynamo, which are visual programming environments for Rhinoceros 3D and Revit respectively, allow users to explore a variety of different design interventions and determine optimal solutions. Prior to starting the daylight analysis, we began with a “base geometry” of the existing conditions that we modeled in Rhinoceros 3D. We then developed a Grasshopper file to create daylighting interventions. For this study the interventions consisted of interior light shelves and exterior shading devices based on numerical inputs for shelf depth and height. Using Grasshopper in lieu of traditional 3D modeling allowed us to systematically test multiple variations of intervention geometry. In addition to studying how new geometries would impact daylighting we also studied how existing/new materials could impact daylighting performance.
on Best Practices for Providing Effective Daylight in Mid-Century Modern Structures

The daylighting analysis was performed using DIVA for Rhino, a plug-in that performs daylighting and energy analysis directly in Rhino. DIVA also offers several Grasshopper nodes, allowing the analysis to be controlled and managed directly in Grasshopper. For this analysis the primary results we extracted and used to measure performance included:

Annual Daylight: Percentage of time space receives at least 300 lux. This value can be mapped over the area under analysis. Typically, areas that receive 300 lux at least 50% of the time have the potential for daylighting.

Spatial Daylight Autonomy (sDA): Percentage of a space that receives 300 lux for at least 50% of the annual occupied hours. This metric provides a single number for quickly determining daylight potential. A value over 55 indicates that daylighting will be at a minimum nominally accepted by occupants. A value over 75 denotes a space where daylighting will likely be preferred by occupants.

Annual Sunlight Exposure (ASE): Percentage of a space that receives over 1,000 lux for at least 250 hours per year. High values indicate that the space may be overlit and cause glare/discomfort.

Daylight Factor: A ratio comparing light levels on the interior of the structure to the light levels on the exterior. Typically, a value under 2% indicates that the space cannot be adequately daylit, a value between 2%-5% is preferred for daylighting, and a value over 5% indicates that the space is well daylight, but may be overlit.

on Best Practices for Providing Effective Daylight in Mid-Century Modern Structures

CONCLUSIONS
Reflective interior surfaces can have a significant impact on daylight distribution.

Without any shading there is a high probability for glare according to ASE and DF values.

Interior light shelves alone can reduce the ASE values and the probability of glare.

Interior light shelves alone are not as effective as exterior shading devices in reducing glare.

A combination of reflective interior materials, interior light shelves, and exterior shading devices is the most effective method to provide adequate levels and even distribution of light.

Written and presented by Halla Hoffer, AIA, Assoc. DBIA / Associate

Abstract: Best Practices for Providing Effective Daylight in Mid-Century Modern Structures

When we think of energy conservation standards for our built environment an increasing amount of existing buildings do not comply with today’s standards. A large portion of these existing buildings are from the mid-century modern era. Additionally, mid-century modern buildings are approaching historic status, if not already there. This status compounds finding the best way to integrate current energy standards because aesthetic impacts to a historic resource must be kept to a minimum. At PMA we believe that while challenging, it is possible to maintain the integrity of historic mid-century modern buildings while meeting new energy conservation requirements. In an effort to explore this possibility, we have submitted an abstract for an upcoming Energy Conservation in Mid-Century Modern Buildings Symposium presented jointly by APT Northwest and DOCOMOMO_Oregon.
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ABSTRACT: BEST PRACTICES FOR PROVIDING EFFECTIVE DAYLIGHT IN MID-CENTURY MODERN STRUCTURES
Effective daylighting can reduce both lighting and cooling loads while improving user comfort, satisfaction, and health. Despite plentiful glass, using daylight in mid-century modern building can be challenging. Glare and uneven light distribution can cause user discomfort and pose challenges to effectively daylighting spaces. Frequently, artificial lighting is used to balance lighting in spaces over lit by the sun, negating any potential energy savings. For existing buildings, the available methods to provide effective daylighting are limited by the existing constructions and configuration. To both preserve existing structures and provide ample daylight a critical question must be answered – what are the best practices for improving daylight in existing buildings? This study provides insight to daylighting existing structures, specifically, how light can be controlled and distributed in mid-century modern buildings with plentiful glazing.

Emerging tools and technologies provide effective methods of analyzing hundreds of different daylighting simulations. Applications such as Grasshopper and Dynamo allow users to explore a variety of different design interventions and determine optimal solutions. This study explores and analyzes how common daylighting strategies can be implemented on existing mid-century modern structures. The study focuses on a 1963 residential tower in Portland, Oregon, and explores how interior reflectivity, interior/exterior light shelves, shading, and glazing can impact daylight availability and distribution. The study looks at a variety of ways each strategy can be implemented and analyzes the results to determine best practices based on daylight distribution/availability, glare, lighting loads, and heating/cooling loads.

Speaker Bio
Halla Hoffer, AIA, Assoc. DBIA
Associate / Peter Meijer Architect, PC

Halla is passionate about rehabilitating historic and existing architecture by integrating the latest energy technologies to maintain the structures inherent sustainability. Halla joined PMA in 2012 and was promoted to Associate in 2016. She is a specialist in energy and environmental management, as well as building science performance for civic, educational, and residential resources. Halla meets the Secretary of the Interior’s Historic Preservation Professional Qualification Standards (36 CFR Part 61).

Historic Atrium Lighting Design

The concepts for our lighting schemes were based on the intended function of each identical space. The focus of the design and specified need of the client was to provide lighting for evening social gatherings, networking, and overall entertaining. Lighting needed to be adequate enough for speakers presenting to a crowd and for listeners to be able to read any related literature. Therefore, it was crucial to design lighting schemes that could provide ample lighting for evening events without compromising the historic integrity and ambiance of each space.

The prominent design goal was to increase overall light levels through a refined, modern scheme that would provide juxtaposition to the historic architectural elements and hanging sculpture. As in any historic project, it is important to avoid solutions that are faux historic, competing with, compromising, or confusing the original historic character. The few pragmatic design parameters defined by the client allowed for design freedom to provide several unique, distinct solutions.

While creating our designs, PMA experimented with the type of fixtures (down lights, sconce, defused) and placement of these fixtures within the large volume of the atriums. PMA explored these options in a Revit model of the atrium spaces, which enabled evaluation of the design solutions through lifelike renderings that portrayed the quality and levels of light.

The Form and Function of Lighting Design

When we experience an interior architectural space, lighting plays a large role in setting the mood and functionality of a space. No matter an existing, modern or historic building, light of a space is a critical aspect of great interior design. Lighting elements can be designed to enhance the space and architectural details, set the mood, and compliment furniture, color schemes, and art work. For spaces without an abundance of natural light, lighting design becomes even more critical design consideration. For a recent project, PMA designed lighting schemes for two historic four-story tall interior atriums.

The existing atriums utilize natural light from skylights above; however the original design provided no artificial overhead lighting in the space. During the winter months or at dusk and night, the light quality of space relies on the little ambient light from the skylights or artificial light from the surrounding rooms and halls. The light during these times is inadequate for the necessary function of the space. PMA was tasked with providing a lighting solution that would sensitively address the historic nature of the atriums and provide adequate visibility in the space.
pmapdx-lighting-design-004
Defining the Project Challenges
The concepts for our lighting schemes were based on the intended function of each identical space. The focus of the design and specified need of the client was to provide lighting for evening social gatherings, networking, and overall entertaining. Lighting needed to be adequate enough for speakers presenting to a crowd and for listeners to be able to read any related literature. Therefore, it was crucial to design lighting schemes that could provide ample lighting for evening events without compromising the historic integrity and ambiance of each space. To provide a solution for our clients’ challenge, we considered the following when approaching our design for the lighting schemes:

How to provide power to the source of lighting without compromising the historic elements.

Designing for large volumes of vertical space: hanging lighting within the atrium versus lighting from the top; how the light travels in the space, how it casts down shadows, the reflections off the floor and other surfaces.

One atrium exhibits permanent hanging sculptures and art; the lighting design required minimal approach to integrated and highlight the sculpture without distracting from it.

Designing for and highlighting the atriums’ architectural details, like the cornices, in addition how to hide or incorporating other non-historic architectural details like the structural support columns.

pmapdx-lighting-design-002
Methodology for Design Solutions
The prominent design goal was to increase overall light levels through a refined, modern scheme that would provide juxtaposition to the historic architectural elements and hanging sculpture. As in any historic project, it is important to avoid solutions that are faux historic, competing with, compromising, or confusing the original historic character. The few pragmatic design parameters defined by the client allowed for design freedom to provide several unique, distinct solutions. While creating our designs, PMA experimented with the type of fixtures (down lights, sconce, defused) and placement of these fixtures within the large volume of the atriums. PMA explored these options in a Revit model of the atrium spaces, which enabled evaluation of the design solutions through lifelike renderings that portrayed the quality and levels of light. Illuminance studies of lux levels provided a way to evaluate each design and provide refinement to meet necessary levels defined by the function of the space. Some lighting design options included:

Design lighting to highlight and contrast architectural features from surroundings, for example placing fixtures in the cove of architecture cornices located above openings within the atrium.

One atrium has a glass block floor element which could be illuminated from below to provide a dramatic light feature.

Accenting the verticality of the space with defused ribbon lighting set within the non-historic structural C-channels. This would transform these elements into elegant vertical lines leading the eye to the above skylights.

Pendant lights interspersed between sculptures would provide orbs of light to highlight elements of the sculpture. These fixtures would provide defused-light with optional downlights within the same fixture.

Suspended down lights at top of atrium with lights accenting sculptures from above and side.

Wall sconces to accents light and wash the atrium walls and columns; this would provide an overall glow to the space.

pmapdx-lighting-design-001
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Scheme 1 unified serval lighting design ideas to provide different light level options in the space. Wall sconce lights provide general illumination of the space. Large circular hanging fixtures consist of defused tube lights and large circular defused downlights. Each group of fixture types can be controlled independently and dimmed to provide the ambience desired.

Scheme 2 specifically works with the sculptures in the second atrium space. Vertical ribbon lights provide ambience illuminance of the space while concealing non-historic structural elements. Pendant lights hang interspersed within the sculptural elements. These have a defused light with an option for downlights. Each grouping of fixtures can be illuminated together or separately depending on the quality of light needed.

Scheme 3 was chosen by the client and until announced must remain confidential. Stay tuned for the reveal.

Written by Hali Knight.