Colleges and Universities
College and university campuses provide such a variety of services that they are essentially a small town or individual neighborhood in a city. The individual building energy needs vary widely and are dependent on the specific building use and its location on the campus. Some campuses are spread out with a great deal of grassed areas between buildings, while others are tightly packed into the downtown areas of a city. Buildings range from single story spread-out types to high-rise structures. Many campuses are installing central monitoring and building access control, even with distributed systems, to reduce labor costs and staffing. These combine fire and security systems as well as HVAC controls.
Functions also include:
- Scheduling remote equipment start and stop actions,
- Demand limiting load shedding for peak electrical load control,
- Duty cycling to cycle constant volume equipment during part load operation,
- Lighting controls to shut off lighting in unoccupied areas,
- Maintenance scheduling for failure prevention and routine repairs, and
- Accurate record keeping to track energy use and identify energy saving opportunities.
Some of these building types include:
|Gymnasium||Natatorium||Ice Rink||Tennis Pavilion||Storage|
|Stores & Eating Facilities||Student & Faculty Housing||Maintenance & Repair Shops||Central Plant (Boilers, Refrig., etc.)||Radio Station|
|Hospital||Chapel||Film/TV Studio||Student Union||Animal Quarters|
- Those designed with multiple unitary systems
- Those where the school started small and just grew and grew. (It is not unusual to encounter a conglomeration of energy systems on any one campus.)
- Central plants may serve some or many buildings while still others have independent systems.
Most college buildings were not constructed all at the same time; usually, the school started small and expanded as needs grew and funds became available. Therefore it is not unusual to encounter a conglomeration of HVAC systems on any one campus. In past years, ventilation dominated, however new buildings are being constructed with air conditioning.
Central plants may serve some or many buildings while still others have independent systems. The HVAC systems will vary widely depending on the size, age, and geographical location of the buildings. Larger campuses usually have a central boiler or boiler/chilled water plant with distribution piping to each building; others use central heating systems with one or more chillers in each building. In climates with low heating loads, electric resistance heating is often used.
Other buildings are designed with multiple unitary systems using roof-top heating and cooling units; one per classroom or zone. Some of the newer buildings on decentralized campuses are using a geothermal heat pump system. This is particularly necessary when occupancy hours vary. Loads can vary widely and quickly switch from heating to cooling; only requiring automatic and simple-to-operate controls. Special purpose spaces, such as gymnasiums, libraries, computer rooms, and offices, may require separate treatment.
Central plant systems usually have a lower installed cost per given unit of energy capacity. However, the cost of and losses in distribution, piping (above ground, buried, or in utility tunnels), and pumping may offset these lower energy unit costs. Detailed analyses of centralized concepts versus individual plants should be evaluated with considerations for projections of future growth.
These factors should be considered:
- Central versus individual building maintenance
- Noise and environmental controls and restrictions
- Topography and easement characteristics
- Distribution type (steam, high temp. hot water, chilled water, tower water, etc.) and location of piping (above ground, buried or in utility tunnels)
- Fuel availability and storage, as well as other potential energy sources (ground or well water, etc.), and planned diversity of equipment types and functions
- Building hours and operating schedules, and diversity factors
- Plans for future expansion
Decentralization, especially in steam plants, has been justified in some areas, because of the hidden operating cost. This is predominantly true where the central plant serves a wide range of loads which results in low equipment loading for much of the year. For example, a boiler serving space heat in a number of buildings may have to run year-round because of water heating in one building. An ASHRAE study found that the average central steam plant had an annual efficiency of fifty-five (55%) percent.
Proper ventilation is necessary to control odors and avoid "sick building" syndrome. Provisions should be made to shut any outdoor air dampers when individual zones or rooms are unoccupied. Many areas have stringent codes regarding fire, smoke, building design, ventilation, and noise control. In many cases, noise production and protection from vandalism must also be considered. As an alternative to roof-top equipment, geothermal heat pump systems are increasing in popularity as they have no outdoor equipment to create noise or be damaged.
Energy Saving Recommendations
Energy conservation concepts should be simple: cooling interior spaces with outdoor air-using economizer cycles, night setback in individual areas, and outdoor air damper control during the system shutdown at night. Water-loop heat pump systems may also be used to conserve energy if the building has significant interior zones. In fact, it may be possible to justify upgrading to higher-efficiency equipment, or even a complete redesign to geothermal heat pumps, as existing HVAC equipment ages and must be replaced. Some designs combine thermal storage, where excess heat generated during the day is stored and used for heating at a later time.
Service water heating is needed for janitorial work, restrooms, cafeterias, and occasionally for shower rooms and swimming pools. Cafeterias, shower rooms and swimming pools usually have their own water heating systems due to loading and temperature characteristics. Hot water used in cafeterias is about 70% of that usually required in a commercial restaurant, but can still be estimated with the same method used for restaurants. Where NSF sizing is required, follow Standard 5.
Energy Saving Recommendations
Most energy conservation measures regarding water heating in schools will be about supplementing cafeteria water heaters with either heat pump water heaters - located in the cooking area - or heat recovery water heaters attached to the refrigeration systems. If a central water heater is used for restrooms or laboratories, then point-of-use water heaters will also provide good payback. Provision must be made to supply 180°F sanitizing rinse in the kitchen, usually with electric booster heaters. Shower and food service loads are not ordinarily concurrent. Each should be determined separately, and the larger load should determine the size of the water heater(s) and the tank whenever a single system is going to supply both loads. The booster must be sized according to the temperature of the supply water. Please refer to the Water Heating section for more detailed assistance.
Colleges and universities typically have cafeteria-style and fast food-style restaurants. These restaurants are frequently out-sourced to commercial kitchens that have their own design preferences. Many of these restaurants are installed in buildings that weren't originally designed to handle them, so please review the technical section on building reuse for guidance.
Lecture halls differ from classrooms in that they're designed for larger groups of anywhere from 25 to several hundred students. The lecture room often has a sloping floor so that larger groups can maintain good visual contact with the instructor.
Energy Saving Recommendations
When placing fixtures, keep in mind that the desk/work surface in lecture halls is usually fixed. Light levels needed vary from 5 footcandles for audio/visual demonstrations to as high as 50-100 footcandles for reading and writing. Use light sources with a 3500 to 4100K color temperature and at least 70 CRI. Fluorescent and incandescent lamps are both appropriate. Incandescent halogen downlights are often combined with fluorescent to provide maximum flexibility. Fluorescent fixtures are generally not installed alone because they need flexible switching controls or dimming ballasts to provide varying light levels.