Examine operating conditions to confirm how likely you are to meet the credit requirements.

Provide occupant controls for each individual space and avoid trying to normalize conditions in large areas or zones of a building. Separate controls will make it easier to achieve the credit in all spaces and improve occupant comfort while reducing unneeded energy use. For example, if there are ten adjacent offices, provide controls for each office separately. This strategy can also help you earn IEQc6.2: Controllability of Systems—Thermal Comfort. Added controls may increase upfront costs, but reduced energy consumption should help offset those costs.

Natural ventilation designs are more significantly affected by climate and weather than mechanical systems. Although the methodology and inputs for documenting compliance are the same as for mechanical systems, in certain regions project teams using passive systems may have difficulty meeting ASHRAE-55 due to program constraints or seasonal temperatures that are outside of the prescribed range of 50°F–92°F. 

Don’t assume that projects in Southwestern or other dry climates will automatically meet the humidity requirements of ASHRAE-55. These climates may have a significant number of days in which operating conditions will exceed the ASHRAE-55 requirements for humidity. Refer to the National Climatic Data Center for regional weather data (see Resources). 

Include credit-related information in the Basis of Design for the commissioning credits EAp1 and EAc3. At a minimum this should include:

that you require compliance with this credit;
that you require compliance with ASHRAE-55;
and what operating ranges should be maintained.

Review how thermal controls and operable windows affect credit requirements. Projects in very temperate climates may meet the credit requirements through the use of operable windows exclusively, as long as mean monthly outdoor temperatures are between 50°F–92°F. See ASHRAE-55 section 5.3 for details. 

Review ASHRAE-55 section 6.1.1 to understand the credit documentation requirements. Assess these inputs:

Weather design conditions for peak load
Hours per typical year that outdoor temperatures exceed design conditions
Maximum design humidity
Design air speed
Radiant temperature asymmetry (refers to the changes in personal temperature around the body as affected by differences in nearby surface temperatures, such as heated floors and cold windows)
Vertical air temperature difference
Floor surface temperature
Drafts

When beginning to consider thermal conditioning systems, review which system types will not only meet credit requirements, but will balance performance, efficiency and cost while creating an optimal thermal environment in the given climatic region. In some regions, direct evaporative cooling may be an appropriate option, while in others dehumidification may be needed to meet the credit requirements. Review the feasibility of natural ventilation systems versus mechanical systems and consider their effect on energy use, programming, and credit achievement. 

Determine which HVAC system types (mechanical, mixed mode, or natural) and system components can best meet the credit requirements and review any special programming requirements for ventilation, humidity and thermal conditions. For example, consider whether in-floor radiant heating is preferable to forced-air systems and which are best suited to a project’s programming and budget, and confirm that the system will be capable of operating within the established comfort zone. 

Review how building systems might contribute to or hinder achievement of this credit and review site-specific conditions that will affect building conditioning.