Duct cleaning and a healthy indoor environment may be related, but only under certain specific circumstances. The average residential central cooling and heating system conveys about 1,400 cubic feet of air per minute through the ducts and into living spaces. Whatever is carried by that current of air tends to accumulate in the ducts, and whatever is in the ducts can be carried back into living spaces. Because today’s homes are tightly sealed with little natural ventilation, airborne contaminants can concentrate to levels that may exceed the threshold for good indoor air quality — particularly for persons with allergic sensitivities.
Do You Need Duct Cleaning?
A typical home incorporates a couple of hundred feet of trunk and branch ducts. The overwhelming majority of this span is inaccessible to the typical homeowner. Whatever happens inside ducts that are routed inside wall voids, through the crawl space and up into the attic is a mystery to anyone other than an HVAC professional with the expertise and tools to perform a thorough duct inspection.
A proper procedure involves directly inspecting ductwork by removing access plates and/or disconnecting spans of ducts at joints. The condition of ducts can never be accurately evaluated simply by making assumptions based on the age of the home, nor by merely peering into a supply or return vent with a flashlight.
What’s Happening in the Ducts?
First of all, there’s probably a light coating of dust and household dirt. Static electricity causes dust in the airflow to naturally cling to duct surfaces. That’s entirely normal and, by itself, not a red flag that requires duct cleaning. Here are some scenarios, however, that might prompt you to ask your HVAC contractor to take a closer look at your ducts:
- Suspected presence of mold – Dormant microscopic mold spores circulate in air everywhere, including inside ductwork. Active mold growth, however, is another matter. Growing mold releases reproductive spores that carry mycotoxins that may cause allergic reactions or even respiratory illness in certain residents. Any suspected organic growth inside ducts must be physically sampled and tested to confirm active mold as well as the type of mold.
- Water infiltration – If water has entered the ducts from sources such as a flooded crawl space or roof leakage that penetrates ducts routed through the attic, bacteria, mildew and active mold growth, not to mention noxious odors, may result when dry residue inside ducts becomes soaked. Duct drying and cleaning is the only way to eliminate these potential hazards.
- Infestations – Evidence of occupation by rodents, bees or other pests is a signal that duct cleaning is required. Even if the infestation is neutralized, decomposing remains and droppings will pose a potential health issue to your breathing air.
What’s Involved In Duct Cleaning?
Most qualified professionals utilize negative pressure, a standardized duct cleaning procedure that combines a powerful vacuum force with specialized tools to clean the entire span of ductwork without contaminating the home. The process requires four steps:
- Technicians access the ducts through inspection plates, via removable end caps, and supply and return vents. Where necessary, small access holes may be cut to accommodate tools and later re-sealed.
- The techs use air-driven brushes, compressed air streams and other agitation tools to loosen accumulated dust and debris from duct surfaces.
- Working in one duct segment at a time, vents and other openings not utilized for tools are sealed. A strong vacuum is connected to the segment, inducing powerful suction force that removes loosened particulates and debris from the ductwork, then channels it into plastic bags for disposal. The vacuum air exhaust stream is cleansed by a HEPA-grade filter to prevent dust infiltration into the living spaces.
- Associated components in the system airflow like the evaporator coil, blower fan and furnace plenum are also cleaned. After reconnecting all segments and sealing any access holes, a new air filter is installed and the system is test-run.
Learn more about Aqua Plumbing & Air’s professional duct cleaning services, or call (941) 306-3715 to schedule an appointment for your Sarasota area home!
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