Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
ASHRAE appendix G says: The equipment capacities for the baseline building design shall be based on sizing runs for each orientation (per Table G3.1, No. 5a) and shall be oversized by 15% for cooling and 25% for heating, i.e., the ratio between the capacities used in the annual simulations and the capacities determined by the sizing runs shall be 1.15 for cooling and 1.25 for heating.
If you oversize more than 1.15 your chiller would work with a lower EER most of the time.
