In Equal Measure

Creating education buildings that are conducive to learning depends on more than just providing sufficient space for students and faculty. Behind the scenes, heating, ventilating, lighting, finishes and furnishings all require careful consideration to achieve the highest quality and most productive indoor environment.

The range of spaces on a typical campus offers a broad array of indoor environmental conditions, from normal to extreme. At one end, general-studies classrooms are the most typical spaces, and the systems necessary to produce a high-quality environment are more commonplace. At the other end are swimming pools and ice arenas, each with unusually demanding requirements for space conditioning. In between these extremes are other typical areas, each with its own particular environmental requirements, such as large-group instruction and public assembly spaces, laboratories, museums and gymnasiums.

Long before selecting lighting, HVAC systems, materials and furniture, planners use energy modeling as a tool in project design. Modeling gives designers and administrators a clear picture of new energy technologies and facilitates decisionmaking. A preliminary design of the building's envelope can be created using energy-modeling software. Planners seek the most energy-efficient approach as various alternatives are explored for the building's orientation, space occupancy, lighting and HVAC systems and the overall envelope design. Building on this base, designers can study different options that affect daylighting, mechanical and electrical systems, glazing and insulation. Institutions can predict how each factor will affect the building's energy consumption by comparing the cost of various options with their life-cycle costs. The result can shape the building's design from early-concept studies through production of construction documents.

In general

Students spend the greatest amount of time in general-studies classrooms. In these spaces, a high-quality environment can greatly enhance learning. Classrooms also are the smallest of an institution's spaces, so the effect on an individual from lighting and ventilation, and the potential for toxic gasses can be the most intense. In these spaces, every aspect of environmental quality must be accommodated.

Providing ample daylighting is critical in classrooms. Recent studies demonstrate that natural illumination aids learning significantly. The design challenge is in maximizing daylighting so that the integrated use of artificial lighting can be controlled and reduced as much as possible. Producing high-quality, non-glare light will improve student performance and reduce energy consumption.

Design decisions that help reach this goal may include introducing light at the corners of a classroom, eliminating glare in the room's center. Large corner windows preserve the exterior wall for teaching space, maintain an internal connection with the natural world, and minimize the distraction that may occur in a classroom with a full wall of windows. In classrooms on a building's top floor, skylights also can be incorporated for natural lighting.

Lighting systems that are designed to achieve the correct proportion of indirect and direct light can reduce glare. Increased use of computer presentations and laptop computers make these concerns critical.

Providing the right level of thermal comfort for a typical classroom of 25 to 30 students must be coordinated efficiently with other systems in the building. The thermal load for each space is determined through the energy-modeling process for optimum energy efficiency. Controlling the use of artificial lighting can reduce the amount of time an HVAC system is operated.

The desired ceiling height for a classroom must leave ample space available to run ductwork for air conditioning. Air-distribution diffusers should be situated to reach the highest percentage of uniform comfort throughout the room. With a control zone engineered for each classroom, individual thermostats allow for flexibility and comfort accommodation.

Noise control of ventilation systems also enhances the quality of a classroom. Motors positioned at the beginning of an air stream can result in subtle, although annoying, noise in the pathway of the ductwork. Using certain controls can minimize this distraction. Again, the small size of a typical classroom makes this decision more critical, because the effect of ventilation air noise is greater than in a larger space such as a gymnasium.

The selection of materials can contribute to the well-being of the room's occupants. Finish selection backed up by an efficient building-envelope design with proper air barriers can ensure that moisture does not reach materials and produce deterioration and mold. Overall control of the construction process should ensure that materials are properly fit together so that materials such as gypsum, for example, are not exposed to moisture. Ideally, interior finishes should not be installed until the building envelope is complete and humidity control is in place.

Toxicity of interior finishes is a concern. Vinyl products and byproducts that emit volatile organic compounds (VOCs) should be discouraged. A non-VOC paint is a better option and is more affordable. For flooring, carpet tiles are available with low-VOC emissions and provide acoustic benefits for the classroom.

In selecting furniture and cabinetry, wood products with a minimum of urea formaldehyde, such as wheat board, are the best choices. Plastic coverings on furnishings, both fixed and movable, should be removed as soon as possible, allowing several weeks for internal air circulation to eliminate any emissions before occupancy. Air ductwork should be installed so that no dust or debris enters before it is operational.

Larger spaces

Larger student spaces need greater flexibility. In rooms for large-group instruction and public assembly, the numbers of occupants may vary dramatically from day to day and hour to hour. These spaces can be more “dormant” than other areas on campus, yet a wide range of demand is placed on their environmental systems.

System controls need to be designed to strike a balance between the space's maximum capacity and the actual capacity at any given time. One effective approach is through carbon-dioxide-demand ventilation control. This automatically measures the current level of CO in a space and provides fresh air to maintain the carbon dioxide presence at a level below appropriate preset limits.

Just as the right amount and quality of air at different times for varying capacities requires acute control, the same approach applies to the lighting of large assembly spaces. It needs to be controlled appropriately to provide the right quality and intensity for various functions such as recitals, lectures or large performances. A more versatile control system should be installed, making certain that it be designed to accommodate the space when subdivided into smaller areas.

In these larger spaces, the acoustical requirement is higher. A greater amount of acoustical products for ceiling and flooring must be reviewed and selected, especially in music-related rooms. Again, concern for toxicity must be kept in mind and alternatives sought for fiberglass-based products. Noise from the HVAC system persists as a concern in these larger spaces, but can be mitigated by putting fans and motors on a rooftop or remote location.

Special spaces

Isolation is the key responsibility of environmental systems in laboratories. These spaces vary in nature, ranging from physics and teaching labs, both essentially dry labs, to biology and chemistry labs, with wet chemicals. In all laboratories, containment of or isolation from toxic fumes and vibrations is essential to the safety of the occupants and the protection of the experiments.

Mechanical systems working in concert with fume hoods must have the capacity to isolate the exhaust and fumes of one experiment from another, and from adjacent rooms and corridors. For physics labs, in particular, the space must be protected from electrical and static charges. Laboratory partitions should extend from floor to floor and be sealed top and bottom.

Lab illumination depends on the specific function. Lab spaces with multiple computer screens may benefit by less natural illumination and potential glare. In other labs, creativity and innovation in design may permit natural lighting to contribute a positive psychological effect for students and faculty who spend large amounts of time in such spaces.

Museums often are found on college campuses. The importance of a museum's artifacts and art objects determines the planning of environmental systems for these spaces. Protection of valuable objects requires that humidity and temperature be highly controlled to prevent drying, saturation and deterioration.

Natural and artificial light in museums must be controlled to protect objects from ultraviolet radiation. However, effective lighting always must strike a balance between exhibition and conservation. For occupancy comfort, normal environmental technologies are applied, such as thermal conditioning and acoustics.

Gymnasiums

In gymnasiums, occupant thermal comfort is of the highest importance. These are large spaces in which people may come out of a locker room cold and then work out, heating up into a sweat. The challenge is to direct properly conditioned air into the right places because air stratifies easily in such a large space. A three-level occupancy scheme for the HVAC system provides adequate controllability for thermal comfort.

Daylighting at the top of a gymnasium is a solution to eliminate glare that can be a distraction at the gym floor playing surface. Glass block or translucent panels placed high around the entire perimeter of the gym can have a positive effect on the space.

Natatoriums and ice arenas

At the extreme end of indoor environmental requirements are natatoriums and ice arenas. The migration of humidity challenges systems in spaces with large amounts of warm or frozen water. The production of fog is the negative result. In dealing with the atmosphere, humidity in the air needs to be prevented from migrating through the building envelope. This humidity surplus has to be controlled mechanically in concert with an architectural envelope designed to support that control.

In the ice arena, the design of the air system must take into account the need to keep the ice frozen. In this case, the presence of fog is evidence of an ineffective system design. A barrier to humidity can be found in the use of plastic films, glass and other materials. The objective is to design a thermal environment equal to the challenge of a building that often operates 24 hours per day, seven days a week. If the building envelope is not impervious to humidity migration, it is like leaving a door open to moisture migration. Eventually, moisture will fill up the wall cavity fully. Adjacencies to these high-humidity spaces must be controlled so that their space is not pressurized more than adjacent spaces, thus creating the opportunity for moisture to migrate with resultant fog or mold.

Frenette, AIA, is principal-in-charge of education; Dion, AIA, LEED, is senior associate; Halm, PE, is senior associate, HVAC engineer; Ferzacca, PE, is senior associate, electrical engineer; and Oldeman, PE, is associate, HVAC engineer; for Symmes Maini and McKee Associates Inc., Architects, Engineers, Interior Designers and Planners, Cambridge, Mass.