The mechanical system design often includes the distribution of air and a refrigerated or heated medium. Pumps and fans are large components of energy usage. Use variable-frequency drive pumps and a variable-air-volume distribution system to address fluctuating demand. Install sensors and controls to maintain air volumes and reduce energy waste during low-occupancy periods.
Using an integrated design process, the team can easily reduce energy usage below ASHRAE 90.1-2007 thresholds. When designing the lighting layout, the team can take into account the daylighting design of the space in order to reduce the number of fixtures and lower the wattage. The architect can finish the interior space to further enhance lighting efficacy and reduce dependence on mechanical cooling and heating. If appropriate, the mechanical designer should evaluate underfloor air distribution or radiant heat instead of ducted air for higher efficiency.
Lighting loads can be reduced through the use of indirect lighting design, lower ambient light levels with increased task lighting, and efficient fixtures such as LEDs, T5 fluorescent lighting, and compact fluorescent lighting.
Use the ASHRAE compliance forms to update the status of your prerequisite compliance. Typical prescriptive requirements may include a certain heat-pump efficiency rating and the installation of economizers. Building owners may perceive these to be high-cost items, so keep the owner involved in your prescriptive requirement review.
Seek synergy in design disciplines. For example, the layout of interior partitions can have an impact on meeting the mandatory provisions for lighting controls.
If the owner has identified a percentage reduction in energy-use goals—over code or per square foot—the design team should identify measures to achieve them by optimizing mechanical and lighting design, plug-load equipment, and any other energy-using systems.
Explore opportunities to reduce energy demand by identifying all large, energy-using systems in the project. In a typical office, lighting can contribute 30%–50% of a space’s total energy use, with HVAC at 20%–30%, and the rest for equipment and power loads. If your project’s scope allows envelope modification, explore window size and performance, shading systems, and daylight optimization.
Provide independent controls for all task lights. (This can also contribute to earning EAc1.2: Optimize Energy Performance—Lighting Controls and IEQc6.1: Controllability of Systems—Lighting.
