St. Mark’s Hospital – Salt Lake City, Utah


Strategic Energy Management / Re-commissioning


Solarc Energy Group led this comprehensive Strategic Energy Management (SEM) effort that reduced overall energy use by 10% and markedly improved patient comfort.  This team effort involved Solarc’s on-site experts, Rocky Mountain Power’s SEM team, and the hospital’s internal facilities staff.  Work focused on operating improvements to the hospital’s mechanical and electrical systems in a comprehensive and systematic way.  SEM duration was 18 months, starting with a detailed diagnostics effort and concluding with a final savings verification and persistence planning effort.


Project Summary


Hospital size:  517,600 sq.ft.

Verified annual electric energy savings: 1,400,000 kWh

Annual electric cost savings: $112,000

Percentage electrical use reduction: 7.8%

Utility incentive: $28,000

External implementation cost (controls work): $10,000


SEM Measures Implemented to Save Energy


- Occupant education and training

- De-lamp 3-lamp and 4-lamp fixtures

- Scheduling of VAV terminal units

- Increase chilled water enable setpoint

- Aggressive supply air temperature reset

- Optimize condenser water setpoint

- Optimize chilled water reset schedule

- Heating water pump optimization

- Optimize economizer high limit setpoint

- Reduce duct static pressures and inspect/optimize sensor locations

- Scheduling of air handlers

- Schedule exterior fountains both seasonally and at night

- Review and optimize operation of parking garage ventilation system

- Drop steam pressure setpoint by another 5-10 PSIG

- Optimize blow-down practices

- Drop minimum humidity target to 20%

- Reduce ductwork leakage

- Mixed air temperature control optimization

- Optimize primary-secondary chilled water pump and minimize bridge mixing

- Test, repair, and replace leaking hot water valves

- Re-commission stack economizer on boilers


Non-Energy Benefits


- Patient comfort satisfaction increased according to hospital surveys

- Hot/cold calls decreased allowing the maintenance staff to redirect their focus