Intermountain Health Medical Building Sees Big Energy Efficiency Gains

Trust but verify. That’s what CBRE Energy Manager Tim Sullivan thought when he began analyzing energy use at the Midtown Medical building, located at Ogden Street and E 20th Avenue.  

“Starting to look at the data… I started just asking questions like, ‘Hey, what happened to this building? Why is the energy use dropping off a cliff?’” 

Located on the Saint Joseph Hospital campus, Midtown Medical is a tan six-story building constructed in 1988 that hosts hundreds of patients every day for a wide variety of needs—everything from cardiac and pulmonary rehabilitation to primary care and OB/GYN appointments.  

Between 2019 and 2023, the building’s Energy Use Intensity (EUI) score, which defines total energy use divided by total building square footage, dropped 17% from 105.9 to 87.6 kBtu/ft². Sullivan knew that the building’s owner, Intermountain Health, hadn’t made capital investments in energy efficiency during that time period. There wasn’t a large drop in patient traffic. The seasons weren’t any milder with their heating and cooling demands.  

The efficiency gains were so dramatic that Sullivan next reached out to Xcel Energy to check that the meters were working properly. 

“I have seen it happen before that when a utility meter is at end of life it literally just slowly stops spinning/turning as much,” he said. 

But, Xcel verified that the utility meters were working properly. The building’s efficiency gains were real. 

So what caused the huge drop in Midtown Medical’s EUI score?   

The answer, Sullivan discovered, came from a colleague’s tinkering with the building’s antiquated Building Automation System. The trial-and-error process, done by CBRE HVAC Mechanic Mike Engelkes, cost just a few thousand dollars and brought Midtown Medical into compliance with its Energize Denver 2025 interim EUI target in only a few months. After a year of the changes being in place, the building is tracking to meet the Energize Denver final 2030 target as well.  

“This one, it responded really well to changes,” said Engelkes. “I'm really happy with that.” 

Coaxing an Old Automation System Back to Work Its Magic 

Energy Managers know how important automation systems can be. It’s like the thermostat in your house: You save money on your utilities by letting temperatures creep up at night in the summer and drop down in the winter. When the family is using the home during waking hours, temperatures sit between 70 to 74 and everyone’s comfortable. 

But decades-old automation systems aren’t like your average home thermostat. They can be stubborn, finicky devices. Speaking to them and getting them to do what you want can take a lot of trial and error.  

This is why working with old systems is both an art and a science. The “science” is simple: Building managers connect to the old system via a computer interface and use simple commands. The “art” is more complicated: Managers never really know how an older building is going to respond to the new requirements. 

Getting Midtown Medical’s energy savings took some back and forth.  

Engelkes started back in the summer of 2023 when he looked into the occupancy schedules programmed into the building automation system (BAS) to see when the old system thought the building was occupied. 

“There was a schedule in place, but it didn’t work. The building pretty much stayed occupied 24/7,” explains Engelkes. 

Essentially pre-2019 and pre-efficiency, Midtown Medical’s HVAC system saw no difference between 3am and 3pm in terms of temperature and air flow. This meant that building owner Intermountain Health spent thousands on that comfortable 70 to 74 range for building tenants who weren’t there to enjoy it. 

After weeks of tinkering, Engelkes finally got down to the root of how the automation system worked. He tinkered with changes in occupancy hours, and saw how the supporting air handlers, chillers, and other equipment responded.  

All told, he eliminated nearly 49 hours a week of high occupancy temperature control and air handling. This “after hours” sequencing translates into thousands of dollars saved on utility bills. It also means less wear and tear on the components of the HVAC system, which means more savings over the long run. 

The only major spending (just over $23,000) for this project came in when Engelkes worked to make Midtown Medical’s cooling towers more efficient.  

Engelkes fixed a motor mount in the cooling tower and had the tower’s water cleaned to make it more efficient.  

In the end, it’s like Midtown Medical’s HVAC system, the air handlers, the chillers are “just taking your light and dimming it [after hours],” said Engelkes. “And that's where your energy savings are.” 

A Replicable Approach 

Another positive byproduct of Midtown Medical’s changes is fewer tenant calls about building temperature. Pre 2019, some spots were too hot in the summer and too cold in the winter. Getting the system dialed in translated directly into a significant reduction in tenant calls.  

For Tim Sullivan, the CBRE Energy Manager who first crunched the numbers and calculated the building’s EUI score, it all adds up to what he hopes can be a replicable approach. His company manages energy performance for several Intermountain Health buildings near St. Joeseph’s Hospital.  

“The other buildings, you know, every building has its own quirks to it,” notes Sullivan. “We are definitely using the lessons learned here. We're rolling out a similar approach.”  

In other words, working with older buildings’ automation systems can cause a few headaches. But with a bit of elbow grease, the payoff in dollars saved and efficiency gains are undeniable.