Hello,

How are the Thermostat values (Upper and Lower limit) to be selected for LEED CS please? We are currently working on a project for which the climate (Sao Paolo) indicates that the use of natural ventilation may offset the cooling load considerably when the thermostat lower and upper limit values were set to 18°C and 26°C respectively.

When we applied the ASHRAE Internal Conditions presented in EDSL TAS (the dynamic thermal simulation software) the office space is set to have 21.1°C and 22.8°C as the thermostat lower and upper limit values during occupancy hours. TAS explains that this band is set according to 2005 California Standards. This would reduce the effectiveness of a mixed-mode (mechanical + natural ventilation) scenario considerably. Are these thermostat values mandatory for any climate? Does ASHRAE recommend what thermostat values to use? Is it possible to use the 18°C and 26°C as limits?

Your help would be very much appreciated. Thank you in advance for your assistance.