Doernbecher Children’s Hospital  – Oregon Health and Sciences University – Portland, Oregon

 

Energy Modeling / Energy Analysis

 

Doernbecher Children’s Hospital was originally built in 1998.  In 2015, a new MRI wing and additional Operating Room were added.  SOLARC was retained to identify and analyze design changes that could significantly reduce energy use in the overall hospital while improving long-term maintainability for the mechanical systems.  As a result of SOLARC’s analysis and modeling effort, the mechanical design was significantly modified so that all new and existing operating rooms were served by a new dedicated air handling unit.  This allowed control and scheduling changes to be made to both new and existing systems.  SOLARC worked closely with the design team, and especially the mechanical engineer, to define the system changes and coordinate the representation of those changes in the construction documents.  SOLARC also worked closely with the Energy Trust of Oregon to identify and obtain financial incentives associated with the achieved energy savings.

 

Project Summary

 

Hospital size:  280,900 sq.ft.

Annual electric energy savings: 835,290 kWh

Annual natural gas energy savings:  39,600 therms

Annual energy cost savings: $76,150

Utility incentive: $209,000

Cost of efficiency changes:  $408,000

 

Energy Efficiency Strategies Identified and Implemented

 

- Increase the size of new air handler from 19,000 cfm to 37,500 cfm.

- Larger AHU will serve the new iMRI addition as well as existing ORs 1-6 (currently served by ASU-2).

- Re-commission the existing OR HVAC control equipment to ensure functionality.

- Turndown OR airflow (while maintaining space pressurization requirements) during unoccupied periods.     - Modulate fan speed on duct static pressure (DSP) setpoint.

- Reset static pressure on ASU-10 based on zone damper positions.

- Implement discharge air temperature (DAT) reset on the new air handling unit based on zone conditions.     - Install a new floor level network (FLN) panel on the 7th floor.

- Retrofit (18) non-critical terminal units on the 7th floor with digitally controlled terminal equipment controllers (TEC).

- Implement time-based occupied/unoccupied scheduling at zone level on the 7th floor.

- Re-commission mixed air temperature (MAT) control on existing hospital air handling units ASU-1 and ASU-2