Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
By default OpenStudio has the DX heating coil configured to lockout at -8 C. Are you going below that often? OpenStudio also has the coil configured with 2kW electric defrost. Try eliminating that and measure the impact.
If you don't have any set point managers on the coil outlet nodes, OS will provide mixed air SPMs when it creates the idf file. These will be setup to track the supply outlet node, accounting for the downstream fan heat. Each coil will therefore be trying to reach the same temperature. If the dx heating coil is unable to hit that set point the electric coil is going to be left picking up the slack.
