Fan Demand and Energy: Three Air-Distribution Systems ✓ Most Recent

Points out that air system friction losses, high ventilation rates, filter efficiency requirements, part-load air distribution methods and the lack of space for ductwork can combine to make fan demand and energy the largest components in HVAC systems. Writes to place fan power and energy in perspective so that engineers can decide what level of attention to devote to minimizing the operating costs. Focuses on three options for air distribution systems in the cooling mode with a high efficiency 500 ton (1760 kW) chiller rated at 0.5 kW/ton (COP = 7.04). The options include two variable air volume systems and a non-central system with multiple fan coil units. States the options are selected to span the possible range of parasitic fan power from relatively high pressure air handling units coupled with fan powered terminal devices in the zones to low static pressure constant volume fan coil units. Includes corresponding pump and cooling tower power in the analysis, Attempts to compare the resulting system demand. Summarizes in a table suggestions for efficient air distribution system design.