With so many New Yorkers working at home and spending extended hours indoors during the coronavirus pandemic, co-op and condo boards’ thoughts may be turning to indoor air quality. This might be a good time to refurbish a building’s ventilation system – a capital project that may lack great visual appeal but can reap considerable energy savings while improving residents’ comfort, health and peace of mind.
“They probably already have indoor air-quality questions and concerns,” says Amalia Cuadra, the senior director of engineering for the energy consultancy EN-POWER Group. “The biggest point we hear is, ‘I can smell my neighbors smoking or cooking.’”
Dave Sachs, the director of existing buildings at the energy consulting firm Bright Power, says: “Is it the sexiest of things to spend money on? No. But it can have a tremendous impact on health, safety and energy efficiency.”
Two New York City co-ops that EN-POWER has worked on have saved money by purchasing more energy-efficient equipment and sealing off faulty ductwork leaks that let cool air escape during summer and warm air during winter – forcing air conditioning and heating systems to work that much harder.
The dollar savings can get downright sexy. At the 15-story 10 Plaza Street East co-op in Prospect Heights, Brooklyn, a $184,000 ventilation refurbishment in the summer of 2016 is saving about $27,000 a year, Cuadra says. And at the 30-story Plymouth Tower at 340 E. 93rd St. in the Yorkville neighborhood of Manhattan, a ventilation project costing $200,000 (minus an anticipated NYSERDA incentive of $42,800) is expected to save that co-op $26,000 annually, according to Michael Scorrano, the managing director of EN-POWER. After a few years, these upgrades will turn into money-makers.
The Nose Test
How do you know if it’s time for your co-op or condo board to start investigating a ventilation system modernization or upgrade? Resident complaints are one good indicator.
“The specific concerns we often heard were regarding inadequate ventilation of cooking odors or other odors which apparently traveled between floors and were not being vented out of the building,” says Micah Garner of Maxwell-Kates, the managing agent at 10 Plaza Street East. At Plymouth Tower, Scorrano says, shareholders likewise complained of odors and also that the lower floors did not receive any airflow while the upper floors had too much.
Such imbalance occurs when apartments on higher floors, nearer the rooftop exhaust fans, get better ventilation than those on lower floors, which may be getting little or none due to their distance from the roof, poorly functioning fans or obstructions and leaks in the ducts.
The New York City building code requires mechanical ventilation in bathrooms and kitchens without a window. Roof-mounted exhaust fans suck air through vents in the apartments’ walls, then up through a ventilation shaft that runs from the basement to the roof. There can be one or more shafts per apartment line. A vent can be either a grille, with fixed slats, or a register, which allows the resident to adjust the slats.
Opening and closing the slats, however, can affect airflow along the entire line. A device called a constant airflow regulator can counter that by keeping airflow at a fixed level for all apartments on the line. An alternative is a constant exhaust regulator, a cylindrical mechanism installed at each vent. “You set it and forget it,” Scorrano says.
Among the instruments engineers use to test the efficacy of ductwork are an anemometer, which measures airflow rate in terms of cubic feet per minute, and a video inspection camera, which allows an engineer to do a “camera drop” in order to spot obstructions and leaks.
Among the other high-tech instruments: a piece of toilet paper. “An age-old test is the toilet-paper test,” says Sachs of Bright Power. “You take a piece of toilet paper and put it up to the vent. If the toilet paper sticks consistently, then you know you have exhaust ventilation. If it doesn’t stick, then you’re not getting any consistent exhaust ventilation.”
Before beginning any capital project, boards need to make sure of one simple thing, Sachs advises: that the fans are turned on. “You would not believe how often they’re not running,” he says, “either because no one knows about it, no one’s been up there in 20 years, or because it was cheaper to not run it.” Additionally, he notes, most such fans are belt-driven, and the belts wear out every six months or so.
At 10 Plaza Street East, the nine-member board addressed residents’ ventilation concerns by first commissioning a study. EN-POWER verified there was no airflow beyond certain points throughout the building, which was built in 1959 and has 134 units. “They then set up a camera inspection of all the ducts,” says Garner, the property manager. “At points there were complete blockages that looked like debris from original construction that was never cleared out.”
Working systematically from the top floor down, “we entered the units where known blockages were, opened up holes in the wall and had somebody clear up the blockages,” Garner says. “Then we would check further down to see if airflow returned or if there continued to be blockages.”
The board also replaced the roof fans and installed high-capacity constant airflow regulators, which range from about $130 to $350 apiece. With a regulator parked at each vent, Garner says, “we know that proper air is being pulled out of each apartment at the same rate, and there isn’t any backflow into any apartments.”
Cuadra of EN-POWER took a slightly different tack. “We cleaned exhaust ducts and apartment registers to remove debris, cooking grease and dust blocking air flow,” she says. “In addition to the regulators, we also installed fire dampers at the registers, which are designed to close during fires to prevent flames from spreading through ductwork.” Existing rooftop fans were replaced with more appropriately sized fans to match the exhaust rates from the apartments. The new fans run on direct-drive motors instead of belts. “They require less maintenance, consume less electricity and produce much less noise when operating, Cuadra says.
One unexpected problem: Some shareholders’ renovations covered kitchen vents with cabinetry. “We worked with the contractors,” Garner says, “and found the best possible way to access the duct from another wall, such as a bedroom on the other side or even within a closet adjacent to the duct.”
Good Housekeeping Seal
Importantly, at both 10 Plaza Street East and Plymouth Tower, ductwork leaks were sealed. This is done by using an injected spray sealant. “It goes into the ventilation system and finds every hole about the size of a golf ball or smaller, and it steals it,” Cuadra says.
Scorrano, her colleague adds, “It’s almost like a paint sprayer.” The sealant covers pits, pinhole leaks and spots where two ducts are connected with tape and the tape’s falling apart. Larger holes are sealed manually with fiberglass mesh tape and mastic, a type of plastic resin. With such leaks sealed, fans don’t have to work as hard to pull up air, which lowers energy costs.
The Plymouth Tower ventilation project came about as part of a larger energy overhaul, says Steve Dwork, the board president, who since 2014 has been spearheading the building’s conversion from No. 6 heating oil to natural gas, as well as the installation of dedicated domestic water heaters and two co-gen systems to provide electricity and backup power for the building, among other improvements.
Ventilation became part of this overhaul for a simple reason. “Airflow in the building was very inefficient,” Dwork says. “The fans on the roof were either not working, working too much or working too little. Totally out of balance.” Some residents of the roughly 366 apartments in the 1977-vintage building complained of odors. The board worked with EN-POWER, which went into roughly a dozen apartments and also did flow tests throughout the building to get a good overview.
The fans chosen were not the traditional kind but an upblast exhaust fan. “We had those (traditional) big spinning things,” Dwork says, but (the upblast fan) “is a little cleaner, sleeker, and it blows upward, where those mushroom ones kind of blow out and down. We have an active roof – it’s a full pool deck, people eat there – so (upblast fans) interfere less, and also they’re quieter.”
One possible concern can be laid to rest. No peer-reviewed scientific journal has produced any evidence that SARS-CoV-2, the virus that causes COVID-19, can travel from one apartment to another through ventilation shafts. “Let’s say someone in the apartment below who has COVID is cooking and is sneezing and coughing, and the ductwork brings the fumes upstairs,” says Dr. Dean Hart, a microbiologist who has spoken at the United Nations and on network television. “Will that virus live through the transportation of the vents? Theoretically there’s a chance it goes through the vents and sneaks into your nose through the air. Is that possible? Hey, it’s possible I could win the lottery. With all the positive testing in New York City, we would have seen a pattern related to ventilation.”