Working inside a hospital that never closes

The challenge

Hendrick Medical Center

You cannot turn off a hospital. A chilled-water loop serving an operating suite cannot be drained at ten on a Tuesday because it suits the contractor. Every repair has to be planned around a window the facility gives you — and finished inside it.

What we did

• Froze the pipe instead of draining the loop. Isolation valves had to go into the condenser water system on the fourth floor, and draining it would have taken that floor's HVAC down far longer than the window allowed. Our crew shut down the systems serving the floor, isolated the pumps, froze the condenser water lines, held them while the plumbing contractor set the new valves, then flushed and cleaned the condenser water coil before restoring the system and restarting the equipment.
• Four in the morning at the emergency department. An air handler serving the ED at Hendrick Medical Center South needed its coil cleaned. Rather than pick a time that suited us, we proposed 4:00 a.m., the facility approved it, and the unit was back in service before the department filled up.
• Fixed the cause, not the symptom. A boiler kept dropping out on a low-current alarm. The obvious repair was the hot surface ignitor, and we replaced it — but it was failing because the boiler was short-cycling. Working with the manufacturer's technical support we installed a common water temperature sensor across both boilers and set them to cascade. The short-cycling stopped, and so did the service calls.
• Left a number behind, not an impression. On one rooftop unit our technician recorded a 54°F supply air temperature against thermostats set to 74°F, with both cooling stages verified — so the facility has a reading on file rather than a note saying it seemed fine.

Why it matters

Nineteen buildings, one contractor, and a crew that has been in those mechanical rooms enough times to know which valve is which. In a hospital that is worth more than a lower hourly rate.