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Design Guidance

Overall Strategies

The HVAC (Heating, Ventilation, and Air Conditioning) system is the greatest use of energy within the workplace. HVAC systems are most efficient when run at full capacity, making it critical to choose a system that correctly fits the needs of the building. Reduce cooling and heating loads through implementing efficiency strategies such as: installing efficient insulation, preventing air leakage, installing energy efficient windows, and reducing solar gain (e.g. cool roofing and window tints). HVAC systems facilitate the exchange of air to the outside as well as circulation of air within the building, controlling the temperature, removing moisture and contaminates, and distributing fresh air. The mechanical system must be efficient, durable, and sized properly. Prior to occupancy, perform building commissioning. Learn more: Whole Building Systems.


A thermostat is a component of the HVAC controls system. Detection and communication of the space temperature is a critical component of overall HVAC controls. Most new thermostat controls are DDC. Older pneumatic systems can be upgraded to DDC for better control. Zone control is critical.

Sound boots

Sound-boots are integrated into the duct-work between the office walls in the ceiling. The duct work is often shaped like a boot. If properly specified and installed, the sound boot will help control the transfer of sound from one area to another.

Sound Masking

Electronic sound masking systems can be installed in office areas. A sound masking system generates "white noise" that helps mask other sounds. Sound masking systems help make an open office area more functional for the occupants.

Kitchen Exhaust Hoods

Kitchen exhaust hoods are a large energy consumer in cafeteria spaces. Significant amounts of energy can be conserved by utilizing transfer air – conditioned air from adjacent spaces – as replacement air, thus reducing the need for conditioned makeup air. Fan energy can also be saved by reducing air circulation when cooking activity is low. Demand ventilation systems (DVS) conserve energy by vary exhaust and makeup fan speeds in alignment with the demand of existing conditions. ANSI/ASHRAE/IES Standard 90.1opens in new window sets energy efficiency requirements for kitchen exhaust hoods.

Best Practices

  • Install occupant control thermostats that have prescribed temperature range limits to promote occupant comfort.
  • Ensure the air supplied by the HVAC system is properly conditioned - providing comfortable temperature ranges, removing moisture and air contaminants such as odors, dust, and carbon dioxide. Proximity to an exterior wall should be evaluated to minimize ductwork.
  • Ensure the minimum level, or higher, of outside air is circulated within occupied spaces to increase indoor air quality.
  • Use thermostats with occupancy sensors to reduce energy consumption.
  • Use filtration media to removing moisture and air contaminants such as odors, dust, and carbon dioxide.
  • Use underfloor air distribution for reconfigurable technology ready space as power, voice, and data services are easily accessible with access floors.
  • Install IT load meters to track consumption of the computer equipment as a separate item from HVAC or base-building load.
  • Planned in advance and separately zone HVAC in the corridor and set temperatures to conserve energy.
  • Separately zone HVAC in rooms with copy machines to help protect IAQ. Copier equipment gives off a lot of heat when in use, so supplemental air supply may be required.
  • For smaller data rooms consider use of exhaust fans and grills in place of CRAC units.
  • For larger data centers use hot/cold isle strategies to maximize HVAC system performance.
  • Use and maintain supplemental exhaust vents to effectively ventilate restrooms.
  • Consider using carbon dioxide sensors to regulate the circulation of outside air while the enclosed conference room is occupied to increase indoor air quality and save energy.
  • Design HVAC systems to have multiple zones, specifically near south and west facing facades to increase thermal comfort in areas with more severe temperature swings.
  • Conserve energy by using transfer air--conditioned air from adjacent spaces--in order to minimize the need for conditioned makeup air.
  • Design for high efficiency kitchen hoods with low capture and containment (C&C) airflow rates. Ensure air exchange rates are maintained above code minimums, including NFPA 96 and local restrictions, but below ANSI/ASHRAE/IES Standard 90.1non government site opens in new window recommended maximums.
  • Consider automating kitchen exhaust via temperature, smoke, or appliance energy use sensors to optimize performance.
  • Utilize demand control ventilation (DCV) kitchen hoods to conserve energy by reducing exhaust airflow when cooking is not taking place. ASHRAE provides guidance for DCV testing and configuration.
  • Consider heat recovery options to extract heat from kitchen exhaust to reheat ventilation air or service hot water.
  • Evaluate whether chilled beams would meet your laboratory’s cooling needs better than a variable air volume system. Chilled beams not only allow for efficient and even cooling but also minimize air blowing down on lab benches and disturbing scientists' work.
  • Design or retrofit existing labs with energy recovery systems. These may include devices that recover energy from exhaust air, such as enthalpy wheels, heat pipes, or run-around loops.
  • Design ventilation based on real or virtual laboratory models that simulate airflow patterns and optimize ventilation rates under different scenarios (e.g. a spill).
  • Specify low-pressure-drop design for each component of the air distribution system, including air handler coils, energy recovery devices, VAV control devices, zone temperature control devices, ductwork, and exhaust stacks.
  • Consolidate equipment that generates a lot of heat away in an equipment room or away from air supply to manage impact on laboratory cooling needs. Locate exhaust registers above the back of hot equipment to remove it before it recirculates into the room.
  • Control and group substances according to air change rate needs. For example, optimize airflows to do work only up to a certain control band or designate specific hoods for work with certain substances.
  • Provide options to easily increase ventilation in an emergency with an override button.
  • Tailor ventilation to specific tasks and to small labs within a suite, which are equipped with local exhaust (e.g. biosafety cabinet). Some recirculated air workspaces may be appropriate next to 100% exhaust rooms.
  • Design process water cooling into equipment rooms. Water cooled freezers may enable chilled beam cooling of equipment rooms. Be sure to have backup water flow in case of power outage.
  • Exhaust snorkels can be useful in limited applications to remove localized heat or nontoxic particles. They should always have a damper that can be closed off when not in use. Install as few as possible to meet current lab needs. Ducts can be stubbed through the ceiling and closed off to facilitate future snorkel installation if needed.
  • Use a 100% direct exhaust system operated by a timer or the building automation system in order to eliminate odors and improve indoor air quality.

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EB = Existing BuildingsNC = New Construction and Major Renovation

Federal Requirements

Guiding Principles