5,000 cubic feet per minute (CFM) of 25F outside air mixes with 70F return air. The mixed air is heated to 95F as it passes across the heating coil, then across the cooling coil, before being delivered to the building by the supply fan at the specified setpoint of 80F. The unit only operates in the winter to help supplement the load of the DOAS units which provide all the ventilation and typical load requirements of the space. Helpful Information: Density of air: Specific heat of air: Boiler efficiency: Chiller Plant Efficiency: Supply Fan HP (nominal): Electrical Cost: 0.075 lb./ft Density of water: 0.24 BTU/F-lb. Specific heat of water: 84% Natural gas energy 0.65 kW/Ton 30 HP content: Natural Gas Cost: $0.11/kWh 8.34 lb./gallon 1.0 BTU/F-lb. 1,015 BTU/ft $0.0095/ft 3 Calculate the energy cost in $/Hour the unit is current operating at, and identify any opportunities for improvement. Exhaust Air: 70 DEG F 5,000 CFM Outside Air: 25 DEG F 5,000 CFM M www MA 201 Heating Coil Leaving Air Temperature: 95 DEG F Heating Coil Valve: 80% Open Cooling Coil Valve: 0% Open Supply Fan Speed: 75% Return Air: 70 DEG F Supply Air: 80 DEG F 15,000 CFM