Hotel and multifamily projects may have difficulty achieving this credit if they are naturally ventilated and have interior spaces that are further than 25 feet from an operable wall or roof opening. These projects might consider increased window areas, shallower floor plates, or using mixed-mode ventilation so that mechanically supplied outdoor can support areas outside the 25-foot natural ventilation boundary.
Natural ventilation systems may require a more robust and intense integrated design process, consisting of several focused workshops analyzing several alternatives. Computer modeling may be necessary to test various design alternatives to determine which is most effective and efficient.
Laboratory facilities generally require very high ventilation rates. Consider installing separate mechanical systems for lab spaces and other spaces to maximize return-air mixing. Other strategies may include using a heat exchanger to capture energy from laboratory exhaust, using low-flow or variable-flow fume hoods, minimizing ventilation rates during unoccupied times.
New construction projects had median commissioning costs of $1.00/ft2 (or 0.6% of average total construction costs) in a 2004 study of 224 buildings, and yielded a median simple payback period of 4.8 years from energy-efficiency improvements (and excluding quantified non-energy impacts).
Spaces served by the same VAV (variable air volume) controller can be grouped together in the 62MZ calculator, but grouped spaces should have similar exterior exposure.
