One of the latest catchphrases in the school market is "high-performance school." From an HVAC perspective, you might expect this to be an energy-efficient room. You would only be partially correct.

According to Bob Johnson, institutional markets leader for Trane Americas, high-performance schools go beyond being efficient. "A high-performance classroom has two separate paths," he explained. "There's a design path and a delivery path."

Both paths should lead to the same destination, he continued: good indoor environmental quality (IEQ), acoustics, energy efficiency/sustainability - "a whole host of things." Administrators who want their buildings to be certified by LEED (Leadership in Energy and Environmental Design) need to take these considerations very seriously and, at the same time, keep their budgets intact.

"Administrators say, ‘I want to be LEED certified.' The designer says, ‘Here's what LEED costs.' There are budget pressures," Johnson said. "That's where we bridge the gap."

In New Bethel Middle School in Bryant, Ark., for example, "the administrator wanted to take the school to a new level of performance with long-term benefits for the school," Johnson said. (For more information on the project, see the story "HVAC Solutions For Schools" in this issue.)

With assistance from PACT (Performance Assurance for Comfort from Trane), "Part of the costs fell into the school's capital outlays, part lay in our product and service bundling package. It bridged the gap of the budget cycle."

High-Performance Triangle

The high-performance school is described by the Sustainable Buildings Industrial Council (SBIC, www.sbicouncil.org). According to the SBIC, a high-performance school has three characteristics:

1. "It is healthy and productive for students and teachers, in that it provides high levels of acoustic, thermal and visual comfort; large amounts of natural daylight; superior indoor air quality (IAQ); and a safe and secure environment."

2. "It is cost effective to operate and maintain, because its design employs energy analysis tools that optimize energy performance; a life-cycle cost approach that reduces the total costs of ownership; and a commissioning process that ensures the facility will operate in a manner consistent with design intent."

3. "It is sustainable, because it integrates energy conservation and renewable energy strategies; high-performance mechanical and lighting systems; environmentally responsive site planning; environmentally preferable materials and products; and water-efficient design."

Health, maintenance, and sustainability are not separate issues, Johnson pointed out. They can be achieved concurrently.

The PACT initiative is fundamentally the same as performance contracting, he said. "Ours is a measure of Btus reduced.

"We've been in the education market for many, many years," he stated. "Beyond that, if you look at the breadth and depth of the products and services we offer, we have everything that can go into an educational facility, plus the expertise to make sure they deliver what administrators want."

Delivery Of Performance

Gary Luepke is a Trane senior systems engineer working with the education market. He describes himself as a bridge between products and customers.

He has become very familiar with the financial aspects of school systems and how budgets are created. Getting something added to the budget isn't the easiest thing to do, as many budgets are created years in advance. "The construction budget is based on a square foot basis, and it is based on historical budgets," he explained. "The use of historical numbers in the budgeting phase sets them up for problems right away."

School projects tend to be quite complicated because the construction usually comprises additions to existing schools - for example, modifying two wings of the building. "How do you incorporate the new with the old? That's really the challenge," he said.

"For high-performance schools, there are three different pieces underneath it," Luepke said. "It has to be productive for both students and teachers.

"One area that gets a lot more attention is acoustics in the classroom. Children learn differently than adults; they have different hearing requirements," he explained. "Children need to hear every word - they don't fill in the blanks." With more children learning English as a Second Language, acoustics become even more critical.

"Also, there are a lot more children who are hearing impaired in mainstream classrooms, thanks to medical advances such as Cochlear implants," Luepke continued. Although these devices are superior to hearing aids, they still are more sensitive to background sounds. Luepke pointed out that the Acoustical Society of America's Standard ASA S12.60 spells out appropriate sound levels and echo times in different areas of schools. "The sound levels they came up with were quite low, but not unattainable." The standard has not been adopted into code, but it could be used for Americans with Disabilities Act (ADA) compliance.

In addition, "Schools are much more difficult to ventilate than other buildings," he said. Ventilation is based on the number of people for most spaces. In schools, there are 30 to 32 people in each 1,000 square feet of space, and 40 percent to 50 percent outdoor air is required. "It has to be conditioned," Luepke said.

More Training

Training is needed not only for the operation and maintenance of the operations staff, but also for in-house maintenance. "Over the years, as budgets have tightened, the first hits were on the maintenance staff such as housekeeping," Johnson said. Schools would either outsource the service or have teachers responsible for their areas. "We now end up with buildings that are not getting the life that they should."

Training is essential. "In many cases it's a recognized gap," he said. "It's somewhat of a sensitive point with some administrators now - they have a beautiful school built, and it deteriorates."

Automated controls can help, he continued, as long as they are operated properly. "You go back a ways and building automation controls existed, but they weren't understood," he said. "They were disconnected. State-of-the-art controls were intended to do a lot of things, but they were jumpered out to get comfort problems fixed for the moment. Over time, conditions deteriorate."

Training needs to be done annually, Luepke pointed out. "It's not a one-time thing. SBIC says that it's one thing to get that performance when the system is brand new. It's another thing to maintain that level of performance."

Trane's suite of services include training current staff to do a better job of servicing the facility, all the way up to taking over all HVAC service for the school.

"School districts now will sign up for long-term maintenance agreements," Luepke said. The manufacturer will train people who may work on systems for various schools in the area, HVAC contractors, or in-house personnel for the K-12 market. "We haven't even addressed the higher segment yet."

Once annual training is put into a school's budget, there is a much better chance of having it included in the budget for years to come.

Sidebar: School HVAC System Performance

Studies show that the indoor and outdoor environment - indoor air quality (IAQ), acoustics, and energy efficiency - can affect classroom learning. But how often are good, or even excellent systems, operated ineffectually? What can the people who operate the actual systems do to help optimize their performance? In particular, how can school operations staff control moisture, to help minimize potential IAQ problems?

According to Gary Luepke, a Trane senior systems engineer working with the education market, facility managers can minimize moisture problems in their HVAC system by:

  • Installing and regularly replacing air filters. It isn't done as often as it should be, but it needs to be driven home to operations staff.

  • Properly maintaining HVAC equipment, using either qualified internal staff or an outside service firm. In addition to filter changes, this includes checking the condition (cleanliness and level) of oil and refrigerant, maintaining hydronic systems appropriately, cleaning classroom PTACs and PTHPs during unoccupied times, etc.

  • Properly insulating potentially cold surfaces such as walls, roofing, pipes, ducts, etc.

  • Limiting wall and roof leaks as much as possible, by maintaining proper overhangs and limiting the number of holes put into a roof system; and by properly repairing them when they do occur.

  • Increasing air circulation during cold weather.

  • Providing regular housekeeping of carpeted areas and keeping dust (mold food) to a minimum.

  • Installing appropriate dehumidification controls and training staff to use them properly.

    Getting A Handle On Humidity
    When a school is contemplating adding or modifying its HVAC system to better control humidity, it is vital to ask the right questions, in order to get the equipment and control you need.

  • What is the right humidity level for the space? ASHRAE Standard 62.1 specifies that indoor relative humidity be controlled to 65 percent or lower at all operating conditions to reduce the potential for microbial growth. What are the outdoor humidity conditions, as well as uncontrolled indoor humidity conditions? Does humidity during occupied hours need to be raised or lowered?

  • How many hours a year does the school building need to maintain that level? How is it being controlled now?

  • What are the classrooms' occupied times? Are there after-hours classes or uses in the building? (Trane controls can sequence and achieve the humidity set points specified for Trane equipment and other pieces of an HVAC system.)

  • What type of air-handling equipment is available?

  • How do space condition requirements play a role? For instance, is there a swimming pool (natatorium) with naturally higher humidity levels than the rest of the school? Do chemistry labs require special ventilation?

  • What kind of maintenance will the system require, and is the staff qualified to perform it? The performance of systems without proper maintenance decreases over time; therefore, maintaining the system is critical to continue to the required/designed performance (energy consumption, humidity control, acoustics, etc.).

  • Classroom and facility usage changes over time; a maintenance and upgrade program can help ensure that system performance continues to meet the needs of the facility. Make it a point of checking space usage and configuration changes in order to make sure the mechanical system can serve them appropriately.

    Noise Control
    Humidity and IAQ aren't the only areas of concern for schools. Poor classroom acoustics interfere with learning and pose a particular barrier for students with special needs. Classroom noise can come from interior sources such as HVAC equipment and fans in overhead projectors and computers, as well as exterior sources such as aircraft and highway traffic. Excessive mechanical noise can be eliminated at little or no extra cost if the system is designed properly (source: Acoustical Society of America).

    A good listening and learning environment is achievable if classroom acoustics are considered at the outset of the design process. Prediction and analysis tools (like the Trane Acoustics Program [TAP]) assist designers by accurately modeling sound levels in spaces. Manufacturers' engineering experts frequently give assistance and help work out appropriate noise levels.

    - B. Checket-Hanks

    Publication date: 08/08/2005