In a multifamily building with scores, possibly hundreds of people living under one roof, cooking, cleaning, dusting and breathing, it’s no surprise that the airways, chutes and garbage rooms of these buildings can get clogged and dirty over time. Waste material, debris, and allergens can build up in a building’s airways and passages, causing everything from noxious smells to pest issues to bona fide health problems for residents. Air conditioning, climate control and proper handling of waste play a huge role in maintaining not only quality of life, but health as well.

Maintenance and Upkeep

Donald Weekes, CHI, CSP, the Ottawa, Ontario-based president of The Indoor Air Quality Association (IAQA) says that ventilation systems in multifamily buildings should be cleaned on a building by building basis.

“For example if you have a building in Midtown Manhattan or downtown Chicago, it's subject to a variety of different types of pollutants; everything from construction dust to traffic fumes. So you may want to clean your ducts more often than if you are on a farm in Vermont,” says Weekes. “You make sure to gear the frequency of cleanings based on the amount of pollutants you have coming into your ventilation system.”

“The cleaning of duct work is dependent on each individual’s indoor air,” says Bill Benito, ASCA, and president of The National Air Duct Cleaners Association of America (NADCA). “Do you have dogs? Do you have cats? Do you have allergies? Do you have a lot of dirt collecting surfaces like rugs and curtains? There is no easy answer to how often ventilation systems should be cleaned. “

“You should have ducts cleaned only as needed. Ducts have to be inspected and based on the inspection then we recommend you have it cleaned, or not,” says Mike Zouak, CIH, president of Airtek Environmental in New York City. “If there is any visible mold in sight then it should definitely get cleaned. If the ducts are insulated and the insulation gets moldy then it cannot be effectively cleaned, it needs to be replaced. “

“For residential high-rise apartment buildings, cleaning the kitchen, bathroom and building’s hallway air ducts are the first step to improving the indoor air quality,” says Maria Vizzi, president and co-owner of Bronx, New York-based Indoor Environmental Solutions (IES). Another area that should be kept clean is the trash chutes and dryer ducts, Vizzi explains. It’s important to periodically inspect the ductwork in your dryer vent to prevent fires from starting and causing major damage to the unit or the building, she says.

Common Causes

According to the U.S. Environmental Protection Agency (EPA) there are numerous sources of indoor air pollution in any home. Oil, gas, kerosene, coal, wood, tobacco, and building materials and furnishings as diverse as wet or damp carpet, pressed wood products and household cleaning supplies are among common pollutant sources found inside the home.

Immediate effects of indoor air pollutants may show up after one exposure or repeated exposures. These include irritation of the eyes, nose and throat, headaches, dizziness and fatigue. Most immediate effects are short-term and treatable. Oftentimes treatment is simply eliminating the person’s exposure to the source of the pollution if it can be identified. Symptoms of diseases such as asthma, hypersensitivity, pneumonitis and humidifier fever may also show up soon after exposure to some indoor air pollutants.

“Children are especially sensitive to bad air and toxic substances, more vulnerable to their adverse effects. The per capita rates of asthma, for instance, are higher in cities, and the effects of exposure to burning fossil fuels has often been cited as the core culprit,” Vizzi explains.

The EPA says that ‘duct cleaning services typically—but not always—range in cost from $450 to $1,000 per heating and cooling system, depending on the services offered, the size of the system to be cleaned, system accessibility, climatic region, and level of contamination and type of duct material.

“We live on a big ball of dirt. Everybody brings dirt in from the outdoors. When you come in there is all kinds of things on you. When you take off your jacket or your clothes or when your dog or cat comes inside after being outside, all of this accumulates,” says Benito. “The HVAC can be considered the lungs of your house and it breathes the air that you bring in and re-circulates it. A lot of people don’t understand the HVAC system. It only vacuums the air out of the living space - so whatever it’s vacuuming out of the living space is what’s getting caught in the duct system.”

How They Do It

Air duct cleaning removes dust, dust mites and other contaminants from the air duct system and prevents them from being circulated continuously. Ducts have also shown to be an ideal place for spores and other micro fungus to develop and grow. Due to the dark nature of the duct and the available nutrients from outside pollutants the duct can become a breeding ground. In addition, various studies have shown that air duct cleaning can preserve a heating and cooling system. Therefore air duct cleaning is not only cost efficient but mandatory for the health of a building.

According to NADCA, the most effective way to clean air ducts and ventilation systems is to employ source removal methods of cleaning. This requires a contractor to place the system under negative pressure, through the use of a specialized, powerful vacuum. While the vacuum draws air through the system, devices are inserted into the ducts to dislodge any debris that might be stuck to interior surfaces. The debris can then travel down the ducts to the vacuum, which removes it from the system and the home.

“I would call in a professional if I had unwanted smells or odors, or if you had a fire in your condominium or one that was in your same building, if you have allergies or if you have a high humidity situation then you should bring in a certified ventilation inspector.”

Preventative Maintenance

A comprehensive preventative maintenance program can prevent the need for repeated duct cleaning and unnecessary repair costs.

“You should check the air filter and check it often, at least once a season,” says Benito. “I recommend pleated filters and there are Minimum Efficiency Reporting Value (MERV) ratings right on the filters. I would recommend a six to 10 rating, depending on the system.”

“Heating systems filters should be changed regularly according to the manufacturers’ recommendations,” says Zouak. “Filter changing is very important. If you change the filter on a regular basis there would be no need to change the ducts.”

“Consumers need to be very aware that there are unscrupulous duct cleaners out there. They have actually been targeted by attorney generals in various states,” says Benito. “They will do a poor job. The EPA has done a study saying you are better off not cleaning your ducts than having a poor job done. That’s why you should deal with a NADCA certified company. If there are any issues we have an ethics committee.”

At the end of the day, when it comes to providing a healthy indoor environment, the proper monitoring, maintenance, repair and education are imperative. Once that is done, the only thing left to do is to breathe easy.

Christy Smith-Sloman is a staff writer for The Cooperator. Freelance writer George Leposky also contributed to this article.