The Residence at Water Tower Place Condominium Association retained Elara Engineering to perform a holistic review of the building’s ventilation system to identify opportunities to improve performance, reduce energy consumption, and to improve occupant comfort.  The following two-fold design approach reduced energy costs by 50% ($210,000 over the first eight months of operation) and improved occupant comfort through upgrade of the building’s central ventilation systems including reestablishing central humidification and improving building pressurization.

Intelligent Ventilation Control

Demand Controlled Ventilation (DCV) with dampers behind each condominium unit’s exhaust grille that open when exhaust is required (morning, evening) and close when not needed (mid-day, overnight) was utilized to:

• Reduce Fan Power to save significant energy,
• Improve Building Pressurization to reduce air and water infiltration, drafty conditions, and stack effect, and
• Reduce Makeup Air Volume to save significant energy.

Optimization of Makeup Air Unit Performance

Once the building’s exhaust and makeup air systems were operating intelligently, the Makeup Air Units (MAU) were improved by converting the ventilation system to an intelligently controlled demand oriented system, converting existing electric MAUs to gas, and adding three forms of heat recovery.