Hello All,

I'm working on an energy model for a controls rebate for an office building in Kansas City, where I am comparing a VRF system with a DOAS with constant ventilation and a thermostat with 24/7 occupancy, to a similar VRF system with DCV and ASHRAE 90.1 standard office thermostat.

The DOAS for both models have an air-cooled DX coil with a setpoint of 70 F and a natural gas fired heating coil with a setpoint of 75?F. The terminal units are modeled with an air cooled DX coil with a design supply temp of 58?F and a heat pump with design supply temp of 95?F. Both systems model sensible and latent heat reclaim.

I would assume that under the option with controls, during the winter months, the DOAS would heat the building during scheduled occupied hours. Once the system goes in unoccupied mode, the terminal units would heat the space to the unoccupied setpoint. What is weird is that electrical heating consumption is highest in March (See attached for a building summary report). After reviewing the detailed hourly system reports, I'm still not able to figure out what would be causing a high heating load in March. My guess would be something to do the heat reclaim. My question is:

What, within the heat reclaim, be causing the electrical heating demand in March to be so high?

Any help would be appreciated,

Thanks