Because single-duct air-handling units (SDAHUs) supply the cooling air to all zones with the same temperature, the cooling air is normally reheated to satisfy the heating demand inexterior zones in cold seasons. Supply air temperature resetreduces the reheat load; however, it increases the supply airflow rate to the interior zones, which increases the fan power. Dual branchair-handling units (DBAHUs) are proposed to mix the return air with the cooling air to simultaneously distribute the warm air to exterior zones and the cold air to interior zones incold seasons to reduce the reheat load. The purpose of this studyis to investigate the energy performance and control of the proposed DBAHUs through simulations. First, the thermodynamic models are developed for both SDAHUs and DBAHUs,then the system energy performance, including the fan power, terminal box reheat, and cooling coil load, as well as zone CO2 concentration and humidity, is simulated and compared among different systems. The simulation results reveal the proposed DBAHU can significantly reduce the AHU energy consumptionby 12.3 W/m² (1.14 W/ft²) in cold seasons and improve the relative humidity up to 6% with controllable indoor air quality with the CO2 concentration less than 1000 ppm in exterior zones.
Citation: 2018 Winter Conference, Chicago, IL, Technical Papers
Product Details
- Published:
- 2018
- Number of Pages:
- 11
- Units of Measure:
- Dual
- File Size:
- 1 file , 2.7 MB
- Product Code(s):
- D-CH-18-013
