For much of the past 60 years, the 23,000-square-foot First Security Bank building in downtown Missoula was leaking so much air that, depending on the season, it was “heating and cooling Missoula,” according to property manager Scott Cooney. The building’s energy bills, accordingly, were massive.
So, in late 2012, building owner Carol Word worked with the Northwest Energy Efficiency Alliance to start work on a deep energy retrofit, a comprehensive transformation of the building’s insulation, heating, cooling, lighting and power systems. The project is expected to reduce the building’s energy consumption by as much as 70 percent and cut annual energy costs by as much as 46 percent. Because commercial office buildings represent a huge portion of the energy consumption in the U.S., Word said she would encourage other property managers to take a look at investing in energy efficiency as a smart business move.
“Despite the building being old, I was surprised by the opportunities that presented themselves to help not only save energy but also improve tenant comfort, above and beyond just updating our old heating/cooling system,” Word said. “I would encourage other building owners to look outside the box when they consider making renovations or changes to their systems to see where other energy savings lie.”
The building’s six stories house a variety of different tenant businesses, each with different hours and temperature requirements. Built in the 1950s and purchased by Word ten years ago, the building’s heating, ventilation and air-conditioning systems were “literally failing,” according to Cooney.
One of the floors of the building hosts a data center that requires large amounts of power, but even without taking that into account, the building’s electric and natural gas costs prior to the renovation added up to about $45,300 per year.
Word got a few estimates from different engineering firms for updating the HVAC systems, but the costs and proposals varied wildly.
That’s when Northwestern Energy stepped in. It turns out the Northwest Energy Efficiency Alliance was looking for a building in Montana to take part in a pilot project to demonstrate the viability of bringing existing older commercial office buildings into ultra-modern energy efficiency standards. The project is part of the company’s Existing Building Renewal initiative. There are three other larger projects in Boise, Portland and Seattle.
“What makes the EBR initiative innovative is that it focuses on the business benefits of re-positioning a building as energy efficient as well as providing the technical solutions,” said Emily Moore, senior initiative manager at NEEA. “In addition to the energy savings and lower operational costs that can be achieved, a deep energy retrofit can help improve the value of the building by distinguishing it in a competitive market.”
Focusing on commercial real estate office buildings, the goal of the project is to accelerate the adoption of deep energy retrofits in the region.
“We at Northwestern Energy spent a good amount of time trying to find a building in the right place where the building owner would be interested,” said Deb Young, an Efficiency Plus program manager at Northwestern Energy. “Energy efficiency is always about being in the right place at the right time. If she had gone and done a complete cosmetic renovation of this building and then we came along and said ‘oh gee, let’s redo your whole HVAC system,’ she would have thrown us out of here. You have to be here at the time that it works for the building owners. And we were delighted with how it turned out.”
After the Phase I operations and maintenance improvements in October 2012, the October, November and December 2012 bills were reduced by about $2,227.36, a reduction of 18.5 percent in just the first three months. Young said the bills have continued to go down.
Word said she agreed to work with Northwestern Energy because their proposal was an ideal fit.
“It wasn’t just energy savings,” she said. “It was about tenant comfort and the best bet for the future. They were able to do it on a floor-by-floor basis, so there was not as much intrusion and less tenant disruption.”
Air-sealing was one of the first recommendations for the building. The entire exterior surface was worked over, and hundreds of gaps, extrusions and cracks were sealed, insulated and caulked.
“It was exhaustive, their attention to detail,” Word said.
The windows, which before were often inadvertently left open by employees on their lunch break during the heat of the summer, were sealed.
The results were amazing.
“Sealing the envelope saved us 27 percent on our energy costs just like that,” Word explained. “And that was with our old heating and cooling system still installed. When we saw that savings, we were blown away.”
Cooney and Word realized that a staggering amount of heated air in winter and cooled air in the summer had been escaping the building.
“We’re very proud that we’re not doing that anymore,” Word explained.
Modern controls in each office building gave employees the ability to tailor their own comfort level, and street noise was reduced. Many windows are south-facing, so tenants can leave the blinds open to get the view and the sun and still have a cool room in the summer.
“The windows are no longer operable, but it throws the whole building out of balance when you leave ’em open,” Cooney explained.
“The building works as a system,” Word added. “The way we were doing it before, to increase one tenant’s comfort, you had to take air away from somebody else. We had people calling to complain on a regular basis before. Those calls have stopped now.”
Word said the response from the people who work in the building on a daily basis has been overwhelmingly positive.
The next step was to install a series of ultra modern inverters on the roof. They work much like a sophisticated refrigerator coil, but they are capable of sending cooled or heated liquid in insulated pipes to any given area of the building. They are all controlled by computers, so individual tenants can set their preferred temperature.
“The payback on these things is mind-boggling,” Cooney explained. “It can be 40-below outside and you stay warm.”
The inverters are variable-speed, which is the new fad for commercial buildings to manage utility costs. Basically, instead of flipping a switch to turn the whole HVAC system on full-bore in the morning, owners can now just turn on the portion they need.
The first phase of the project included insulating behind the spandrel panels at the south façade, which were previously completely uninsulated. Broken dampers were repaired, and cleaner filters were installed to improve air flow. Time clocks were added to exhaust fans and ventilation systems.
The next phase of the renovation included replacing all the old fluorescent light fixtures with new ones that spread the light out more evenly.
“In the 1950s, the way we designed lighting and office spaces was we put way more light on a surface than we would today with computers,” Young explained. “Lighting is one of the best and easiest ways to reduce energy efficiency in terms of the cost of the investment.”
Many times, Young said, building designers focus on aesthetics rather than energy efficiency when designing a LEED-certified building. As a result, many new buildings have less efficiency than older buildings that have been brought up to code.
There are many challenges and obstacles to retrofitting an older existing building than there would be from designing an energy efficient building from scratch. The old boiler system had to be ripped out, and the tenants still had to work in the building while the construction was underway. This project was meant to show that it can be done without much harm.
“It’s a whole different animal,” Word explained. “It’s challenging. But you have to think about the future. It’s one of the best paybacks you can make, and there are a lot of resources out there, like NEEA, that can help.”
For more information on rebates and incentives for implementing energy efficiency measures, visit northwesternenergy.com/eplus.