CVEN 5020 BUILDING ENERGY AUDITS FALL 2007
University of Colorado at Boulder 1
Homework No. 7
Due November 15, 2007
Problem No. 1:
Solve Problem No. 7.2 of your textbook "Energy Audit of Building Systems: An Engineering
Approach" (p. 227).
Problem No. 2:
A 80,000-sq.ft. office building located in Chicago has a single-duct air conditioning system with
reheat having a 60,000-cfm air handling capacity (60 HP). The return temperature was measured at
74oF while the cold deck air temperature is set at 57oF. Determine the annual energy and cost
savings that could be achieved with a VAV conversion. The following data apply:
Winter Summer
Operating Hours 72 hrs/wk 72 hrs/wk
Length of season 30 wks 21 wks
Cost of Electricity* $0.08/kWh $0.08/kWh
Cost of Fuel (including boiler
efficiency)
$10.0/MMBtu $10.0/MMBtu
* Assume that the cooling system has a COP of 4.0
Assume that the average annual reduction in air flow is 40% when going to a VAV conversion
from a single duct system.
Problem No. 3:
Solve Problem No. 8.2 of your textbook "Energy Audit of Building Systems: An Engineering
Approach" (p. 244).
Problem No. 4:
Solve Problem No. 8.3 of your textbook "Energy Audit of Building Systems: An Engineering
Approach" (p. 244).
