Hot Tip

The surface area of window openings must be equal to or greater than 4% of the total floor area that the design considers naturally ventilated. Multiple windows can provide the operable area needed to meet the requirements.

The calculation for operable openings will only apply to the floor area adjacent to the window: 25 feet to either side and in front of the opening.

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.

Refer to the commissioning plan regularly throughout the project to understand the roles and responsibilities of all team members relative to completing a quality project. It is a valuable document and is regularly under-utilized.

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.

Specifications need to include commission details. If the

A good commissioning specification clarifies subcontractor responsibilities associated with verification and testing.

For Core and Shell projects, occupant densities can be used to determine the number of full time equivalent (

The Ventilation Rate Procedure calculation includes occupancy counts based on space types.

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.