An HVAC Contractor proposes to weatherstrip an office building and install improved controls. This will reduce ventilation rate to 10 CFM per occupant (a total of 1,600 CFM). Added costs for weatherstripping and controls total $2,000. Estimate the first year return on investment if:

Current design is 2,970 CFM winter and 2,400 CFM summer. New design is 1,600 CFM both summer and winter. Annual full load heating hours are 1,600. Annual full load cooling hours are 1,400. Winter TD = 60F, summer TD = 20F; GD (grain difference = 40). Heating will be with the existing equipment, a 75%-efficient oil-fired furnace with $1.00 per gallon oil (140,000 BTU/gal.) Cooling will be with existing equipment with a SEER 8 electric chiller with electricity costs are $0.07/kWh. Note: Add 20% for air handler fan energy.