When It Comes to Steam Boilers, Size Matters
Feb. 27, 2019 — These retrofits to steam heat systems can cut energy costs by 20 percent.
Once upon time in New York City, way back in the 19th century, there were powerful boilers that allowed people to overheat their apartments, which was believed to help prevent Spanish flu. Fresh air was considered healthy, so it was also common for New Yorkers to leave their windows open during the wintertime since those powerful boilers kept apartments from getting cold. This was not a smart system.
Fast forward 170 years. Today, about 80 percent of all New York apartments still have steam heat, boilers still tend to be oversized, and many windows are still open on frigid days. Most energy in New York is consumed by buildings, and most energy in buildings is devoted to producing heat. Multifamily buildings, including co-ops and condos, spend a fortune on fuel – about $1,000 per apartment annually to keep most New Yorkers uncomfortable. This is still not a smart system.
To address the problem, the nonprofit Urban Green Council has produced an invaluable research report called “Demystifying Steam” that can help co-op and condo boards reduce waste and save big on their steam heating systems.
“In the report, we came out with nine specific recommendations which can achieve a 20 percent energy saving,” says John Mandyck, chief executive officer of Urban Green Council. “It all starts with installing the right-sized boiler when the boiler needs to be replaced. That will save capital, which can then be redeployed to other techniques such as thermostats, sensors, and controls, which will bring additional savings.”
Besides getting the right-sized boiler, other fixes include upgrades to the heat distribution system, such as valves, vents, and insulation between radiators and walls.
According to Sean Brennan, Urban Green Council’s associate director of research, most boilers operate far below capacity. “The output is mostly set to something like 50 percent,” he says. “None of these boilers are firing at their full capacity, but a boiler doesn’t function efficiently when set back to 50 percent.” This is why boiler size matters.
“Most boilers are twice as big as they should be, and steam systems are notoriously unbalanced,” says Jonathan Flothow, senior building systems consultant with Steven Winter Associates. “Cold tenants complain, so the super lengthens the heating cycle until everyone’s warm, at which point most apartments are overheated. The goal of balancing is to get steam to the cold apartments more quickly, so that the heating cycles can be shorter. This is how savings are achieved.”
Urban Green Council also published a simple one-page information sheet for co-op and condo boards called “Simple Steam Fixes Save Money.”
Depending on the upgrades, savings will range from $100 to $500 per apartment. It would be pricey to do all the recommended boiler and distribution improvements at once. If the building would contract out all the work, the project would cost about $300 per unit, but paybacks would still be under 10 years.
Flothow recommends working with the building’s personnel. “The radiator work should be well within the competence of the building personnel,” he says. “That would cut the cost in half. I've done several projects this way, always with good results.”
In Flothow’s experience, finding the right contractor is a crucial issue. “Neither installers nor engineers are familiar with these work scopes,” he says. “Fortunately, boards can contact NYC's Retrofit Accelerator program to find trained contractors. Right now that's really their best option to find people who know what they’re doing.”