Consider space programming in collaboration with mechanical system zoning. You may want to link similar functions together for mechanical zoning reasons. A floor with an open-plan office space that will only be occupied in the daytime can be controlled by one zone that allows for a reasonable degree of efficiency. On the other hand, if that open-plan office floor also has enclosed conference rooms and private offices, a single zone won’t allow users to adjust temperature and airflow to the enclosed rooms when they are unoccupied, so energy will be wasted.

If they haven’t done so already, have your design engineer develop a cost estimate for the additional zoning and controls required to meet the requirements. Consider whether the benefits in terms of energy savings and improved indoor air quality of the additional controls are worth the cost of installation.

Review zoning and controls compliance. Make sure that under the proposed mechanical design each interior space with a different exposure is a separate control zone, all appropriate interior spaces have been zoned separately, and that the required demand responsive controls are included.

The majority of space uses can benefit from variable air volume (VAV) distribution. Some projects, like warehouses and data centers, may not include variable load parameters and so would not save energy with VAVs. In those cases, you can provide a supporting narrative arguing against installing VAV. These less typical projects might benefit from following Option 2. 

In typical air-conditioned spaces, 20%–30% of energy used is for delivering the conditioned air to the space through ducts and fans. The volume of air depends on the load requirement, which varies with occupancy, latent heat load, and outside weather. Because of variations within all these parameters, delivered air volume should be modulated in occupied spaces with CO2 monitors, VAV boxes, or both to save energy.

Following Section 3.10: Variable Speed Control, specify variable speed drives on pumps and fans greater than 5 hp. 

Following Section 2.9: Mechanical Equipment Efficiency, specify all systems within your project scope at performance efficiency equal to or higher than the minimum efficiencies listed in CPG Tables 2.9.1–2.9.6. 

If your project is also pursuing IEQc 7.1: Thermal Comfort—Design, the procedures and documentation for that credit will also work for following CPG Section 1.4.

Describe the features of your design that can facilitate efficient operation at part-load conditions, and document how your system plans to maintain adequate ventilation air and comfort as required by ASHRAE-55. 

Pay attention to these key points about implementing the requirements of CPG Section 1.4: Mechanical System Design: