Thermal Comfort (ASHRAE 55) - Select Spaces in Assessment 90.1 2013
Just like in previous versions ASHRAE 90.1 2013 states that schedules and setpoints should be the same for the
baseline and proposed model. However, it now allows the following exception:
Setpoints and schedules for HVAC systems that automatically provide occupant thermal comfort via means
other than directly controlling the air dry-bulb and wet-bulb temperature may be allowed to differ, provided
that equivalent levels of occupant thermal comfort are demonstrated via the methodology in Section 5.2.3 of
ASHRAE Standard 55, "Elevated Air Speed," or Appendix D of Standard 55, "Computer Program for
Calculation of PMV-PPD."
This means the proposed HVAC systems may take advantage of more efficient conditioning methods so long as the
spaces/zones that it serves meets the PMV + elevated air speed analysis from ASHRAE 55-2010.
If applicable, users should set up their space/HVAC parameters with this in mind using the existing action items in
the navigator and, if required, the Macoflo view for setting up operable openings.
A new ‘hermal Comfort’section has been added into the navigator. The three actions allow the user to:
Select spaces to undergo a ASHRAE 55-2010 analysis
Set the ASHRAE 55-2010 options
Enter local comfort conditions
Once complete a new report is available in the results section called ‘hermal Comfort Report’ which outlines if the
ASHRAE 55 analysis has been successful.
In the BPRM report, the UMLH table has also been updated to exclude the ASHRAE 55 spaces from the UMLH
calculation for the proposed model. Note that these spaces will be excluded by virtue of being included in the ‘elect
spaces in assessment’action item regardless of whether they pass or fail the ASHRAE 55 analysis. It is up to the
user to ensure that all spaces included in the ASHRAE 55 analysis have successfully passed all criteria and are
valid.
