At DeVos Its Full Steam Heat
GRAND RAPIDS — Facility managers who don’t do everything under the gray skies to keep a tight lid on heating costs this winter will likely get a cold shoulder from owners and find themselves sitting in a hot seat.
SMG — the firm that manages DeVos Place — may be facing the toughest cost challenge in the region with 162,000 square feet of high-ceilinged exhibit space to heat this winter, the building’s busiest stretch of the year.
Chris Machuta, the firm’s finance director, estimated that heating the convention center from November through March will cost $572,700, a figure that is 76 percent of the total heating charge for the year and 38 percent of all utility costs for the year.
But thankfully only 15 percent of that will go toward buying natural gas, which has risen in price by 37 percent for the state’s commercial customers and by 42 percent for industrial buyers since 1997.
The remaining 85 percent is spent on steam, which warms the building’s vast interior.
SMG’s director of facilities, Ken Dahlman, told the Business Journal that his company has a very practical plan that management follows to keep energy costs as low as possible.
“The policy has us monitoring the lights and the temperature, which could be wasted heat during dark times. The plan also has us utilizing the equipment in order to make it perform economically, even when we do have a heat load,” said Dahlman.
That last point is important. If the building’s temperature rises too high, Dahlman said the system shifts into its cooling mode and the result is wasted energy. Apparently very little was wasted during the previous fiscal year, though, as utility costs came in roughly $90,000 under budget at $1 million.
But Machuta prefers to remain cautious, rather than celebratory.
He said SMG is still learning about the building’s energy costs, and he noted that his firm will start a brand-new lesson in February when the expansive ballroom opens.
“FY 2006 into FY 2007 is when we will have a good handle on the average utility usage for the convention center,” he said.
Progressive AE co-designed the convention center and Progressive engineer Julia Smith — who is also LEED-certified — was the lead mechanical engineer for the $212 million project.
Smith said they used the latest technology to make an old idea work. They installed the most energy-efficient heating system they could find to use the steam that Kent County produces at its Downtown Heating and Cooling Authority.
So how does steam heat the building? Simply put, Smith said heating occurs because the heat exchangers in the building convert the energy from the steam into hot water, and then that water is distributed throughout the building via pipes.
But before that process can happen, the steam must be depressurized. It comes into DeVos Place at 125 pounds per square inch and is diminished by pressure-reducing valves to 50 PSI before the heat exchangers can handle it.
“After it goes to the heat exchangers, you have condensate that comes off it. This condensate still has a huge amount of energy because it is coming from high-pressure steam,” said Smith.
The condensate is then used to heat the ceiling of the parking garage, directly below the convention center floor. Then the heat rises into the exhibit space and meeting rooms.
“Normally, the condensate would go to a drain and would be gone. But we’re reheating it and reusing that condensate,” said Bill Culhane, a LEED-certified architect at Progressive.
“Extracting as much energy as we can,” added Smith.
At times, the amount of energy extracted can be more than needed. When the building is full of people and brightly lit with exhibits — as it was for the woodworkers convention last December — DeVos Place must be cooled, even though the temperature outside may suggest doing that would be silly. Still, the cooling is easily done.
“We just bring in the outside air,” said Smith, who was the lead mechanical engineer on the project.
“There are a couple of spaces that have 100-percent outside air, a steam shop and the lower level storage area. Those two spaces have heat-recovery units in them. That is another way that we tried to save as much energy as we could.”
Besides its efficiency, Smith said simplicity is another benefit of the system, as it doesn’t take up a lot of space. Much of the system consists of three steam-water heat exchangers that have no moving parts, plus a handful of pumps, piping and the converters.
“That’s it. There is a series of valves. But that’s pretty much it,” said Smith.
“There are air-handling units that are basically blowers that have heating elements. The steam heats the water and the water runs those elements, which look like a coil,” said Culhane, who added the elements “spin” the water with a motion that heats the air.
Without a furnace in the building, the boiler that heats DeVos Place is about eight blocks away at Market and Fulton, where the county has its heating and cooling authority.
Because neither unit is in DeVos Place and because no natural gas line runs to the building, Dahlman said the building’s insurance premium is lower than if boiler or line were on site.
Kent County uses natural gas at its plant to generate the steam that heats many buildings downtown, not just DeVos Place. The steam is piped to these structures via an underground system that winds through the central business district, and building owners buy that steam from the county instead of purchasing natural gas or heating oil.
If the county didn’t heat downtown, utility bills for DeVos Place would likely be bigger and the building would likely be smaller.
“We had to fit things within the confines of the building and to add boilers would have been very difficult because there wasn’t enough space, and we would have ended up with very large boilers that would have taken up a lot of space,” said Smith.
“We would have had to have a boiler operator, as well, for that level of boiler.”