Do you really need to pay good money to have your ? The short answer is “probably not.” But before you call up dad to chant “I told you so,” it’s important to understand why you probably don’t need to do it — and why we just italicized “probably.”(Because some people actually should. Hope it’s not you!)In order for your forced-air furnace or HVAC to deliver warm and cool air into your rooms, that air has to go through a system of ducts. So technically, you’re breathing in any dust, cobwebs, pet hair, and dander that line those ducts. Not according to the experts. Dan Stradford, National Air Duct Cleaners Association treasurer and CEO for Action Duct Cleaning in Los Angeles, says there are no conclusive studies saying that duct cleaning will improve your home’s indoor air quality.Asa Foss, LEED residential technical director for the U.S. Green Building Council, concurs. “I’ve never seen any data that suggests duct cleaning has a positive impact on indoor air quality and human health,” he says.

But Foss also says that’s only true when your ducts are airtight. Leaky ducts can pull in dirty air and allergens from basements, crawlspaces, garages, and attics — and blow it all around your house, Foss says.So unless your ducts are leaky (easily fixed with foil-backed duct tape and insulation), or you have a special need, like a compromised immune system, nasty allergies, or you just did major construction, you probably don’t need to worry about air quality when it comes to the state of your air ducts. Of course, there are always exceptions to the rule. Both the EPA and the National Air Duct Cleaners Association recommend professional duct cleaning if you have , vermin (vermin!), or excessive amounts of dirt and debris in your ducts.How do you know if you have vermin in your ducts? You can actually look yourself. Do a visual inspection by pulling off the register grill and looking around with a flashlight, or stick your arm in and take a photo with your phone. (Finally, an excuse to use that selfie stick you got stuck with at your work’s white elephant gift exchange.)

If you see mold, or a dead mouse, or any run-of-the-mill nasty stuff like droppings (ew, we’re so sorry), go ahead and call in a pro. Get those ducts cleaned.Another situation that calls for cleaning, says EPA spokesman Mark MacIntyre, is right after . “You wouldn’t want to have that being dispersed into the house when you turned on the heat.”car ac repair winnipegAnd finally, if you’re just finicky, you just be you. air handling unit autocad blockBe your own special circumstance.“lowes window ac heater unitsWe have customers [for whom] just the thought of dirty ducts is upsetting to them,” says Stradford. OK, so you’re gonna clean your ducts. Your dad will be proud. But be wary of scams. Stay away from companies willing to clean your ducts for $49 or another lowball figure, Stradford says.

Often they’ll do a quick inspection and some vacuuming, tell you there’s mold growth and charge you thousands for clearing it out. It’s common enough that the National Air Duct Cleaners Association has an anti-fraud task force.Look out for duct cleaners claiming they will sanitize your system. “We can’t legally use the words ‘sanitize’ or ’disinfect,’” Stradford says. “By definition sanitizing or disinfecting requires extremely high kill rates and there’s no way we can guarantee 100 percent saturation.”Also, cleaning your ductwork alone is not going to make a difference. A real professional knows that, and should do annual maintenance on your entire system, including the air handler (that’s what they call that big metal box outside that cranks out the noise). {{ start_tip 7 }}Otherwise it’s the same as dusting your ceiling fan after you’ve vacuumed.So how much will it cost, and how long is it going to take? Typically, duct cleaning takes two to five hours, but it can go on for two days if you have a large house with lots of ducts, Stradford says.

On average you should spend $300 to $700.Related: 7 Household Expenses You’re Probably Wasting Your Money OnMOLD can cause health problems that range from itching eyes, sneezing and coughing to serious allergic reactions, asthma attacks and even permanent lung damage. And what many people do not know is that mold could be growing in their homes right now.''I've gone into houses that are so neat and clean there's not even a teacup out of place,'' said Jeffrey C. May, principal of J. May Home Inspections, an indoor air quality testing company in Cambridge, Mass. ''Then I go into the basement and find mold growing on the legs of the furniture.''Mr. May, the author of ''My House Is Killing Me: The Home Guide for Families with Allergies and Asthma'' (Johns Hopkins University Press, 2001), said that while mold in a house is most often found on walls, floors, ceilings, carpets and fabrics exposed to moisture, one particularly troublesome hiding place is inside the ductwork and associated components of central forced-air heating and air-conditioning systems.''

This is the time of year my phone starts to ring off the hook,'' Mr. May said, explaining that as homeowners start up their central heating systems many find themselves suddenly coughing, wheezing and sneezing.Mr. May said that while mold needs moisture, oxygen, a food source and a surface on which to grow, a mold spore in search of a home can come by those essentials relatively easily, even inside a central heating system. That is because such a system constantly circulates mold spores found naturally in the air through parts of the system that often have dust on their surfaces.Once a mold spore has embedded itself in that dust -- which provides the nutrients it needs -- all the spore needs is moisture. And that moisture, Mr. May said, can come from condensation produced by the air-conditioning coil, from a faulty humidifier attached to the system, or even from high levels of humidity in the air itself. While it is possible for mold to grow in the ductwork of a central heating system, he said, it is more common to find it in the parts of the system that collect the most dust and have the greatest potential for being exposed to moisture: the air-conditioning coil and its fiberglass lining, and the cabinet that houses the blower fan.''

I've seen coil linings that were completely infiltrated by mold,'' Mr. May said, adding that when the heating system is turned on, the blower fan distributes mold spores throughout the house. ''Most people don't even know they have a problem until they start getting sick.''In most cases, he said, the only way to determine with certainty whether mold is growing inside a central heating system is to gain access to the coil, its lining and the blower, and take a dust sample from the surface of the components.That sample must then be examined under a microscope. ''I'm looking to see whether there's actively growing mold in the dust,'' Mr. May said.He explained that he looks for actively growing mold because it is possible for mold spores from other areas of the house to get caught in the dust in the furnace.''I'm trying to distinguish between mold that is being collected in the system and mold that is growing in it,'' he said. The cost of an inspection can range from $200 to $1,000 or more, depending on scope and complexity.

If active mold is found in the heating system, Mr. May said, a homeowner should hire a professional remediation expert -- preferably one certified by the National Air Duct Cleaners Association, a trade group based in Washington -- to clean the furnace and the ductwork. ''You want to make sure the whole system is cleaned thoroughly,'' he said, explaining that in addition to removing any dust and mold in the blower cabinet and air-conditioning coil housing, a remediation expert should also clean the interior surfaces of the ductwork with a brush and a HEPA vacuum.If there does not appear to be actively growing mold in the heating system, but members of a household have reason to suspect there is mold elsewhere in the house -- either because inactive spores were found in the heating system or because they are experiencing respiratory problems -- additional testing may be necessary.Joshua Sarett, president of ALC Environmental, a testing and remediation firm in Manhattan, said that when his company inspects a house for a mold problem, the inspector takes air samples from both inside and outside.''

The outdoor reading gives you a baseline,'' he said, explaining that since mold spores are always in the air, it is necessary to look for a difference between the amount and type of mold spores inside and outside.If high levels of hazardous mold spores are found in the house, Mr. Sarett said, the inspector will then make a visual inspection to determine where the mold is growing.Ira Whitman, president of the Whitman Companies, an East Brunswick, N.J., company that specializes in environmental science, said that in most cases the most obvious indication of mold in a house is the presence of dark-colored spots on porous surfaces exposed to moisture.If no obvious signs of mold are visible, Mr. Whitman said, it is possible that mold is growing inside a wall or ceiling.''If you don't see the mold itself, look for signs of moisture,'' he said, explaining that leaks from apartments or appliances on the floor above can saturate the wood, wallboard and insulation in walls and ceilings, creating an ideal incubator.

Determining that mold exists in interior wall cavities, however, requires more work.Damon Gersh, president of Maxons Restorations, a Manhattan company that specializes in restoring damaged property, said that to find mold behind walls it is often necessary to cut holes in wallboard or paneling to insert a small camera.In most cases, he said, small amounts of visible mold on an exterior surface can be removed by scrubbing with a 5 or 10 percent solution of chlorine bleach in water.Mold growing inside a wall, however, can be more difficult to remove. ''In some cases, we have to go in with respirators and Tyvek protective suits and take an entire room down to the studs,'' removing the interior surface of the walls, he said, adding that whenever a mold remediation project is completed, it is critical to make sure that the cause of the problem -- generally the infiltration of moisture into the house as a result of a leak from the roof or poor drainage -- is corrected.The cost of such a cleanup can range from thousands to tens of thousands of dollars.''