Types of air ducts

A high quality duct system greatly minimizes energy loss from ductwork. Leaks in ductwork systems can contribute 20 to 60 percent of the air leakage in a house. The system should be airtight, sized and designed to deliver the correct air flow to each room. Regardless of material, the integrity of air ducts deminishes over time and require replacement. There are many types of air ducts that may be found in a home and each one should be looked at and treated differently. United Air Care is extremely knowledgable of the different types and our technicians are trained to spot each material:

Asbestos Ductwork

Asbestos ductwork, before it became classified as toxic, was considered one of the best insulators for homes. The natural mineral was able to stand up to intense temperature (heat resistant) and its fibrous structure was ideal for keeping temperature in. With low cost and effective attributes, asbestos made its way into millions of homes for up to 60 years. Research on asbestos has been difficult to gather because health problems might not show themselves until 30 years after the fact.

Many doctors are concerned with these lon-term effects, even from just low exposure. Asbestos fibers are able to attach to lung tissue and this can cause cancer growth in the lungs. Not all asbestos ductwork needs to be addressed. If the asbestos is still in tact, it might be wise to leave it be. Many times people try to remove the asbestos and disturb the fibers, releasing them into the air and causing more problems than initially anticipated.

Metal Ductwork
metal_duct

While Metal ductwork are the most durable and can be cleaned, they are old technology and do have their drawbacks. This type of ductwork can be extremely noisy and, although it's not typically excessive, condensation may occur to some degree. In attics this becomes a problem when condensation drips or runs out. This can cause mildew, discoloration, and sagging. Metal ductwork is also somewhat expensive and requires strict installation guidelines. All joints and connections must be sealed before the ducts are insulated.

Fiberglass Ductwork

Fiberglass

Fiberglass ductwork has been a topic of controversy and debate for a number of years now. The reason for alarm is because the fiberglass insulation on most of the ducts are left uncovered on the interior of the duct. When the air conditioner is operating, the air within the ducts becomes cool. This may lead to condensation and as soon as dirt particles are exposed to this, they stick to the surfaces of the duct and cleaning becomes nearly impossible. Additionally, indoor air quality specialists argue that fibers, from the insulation, have the potential to become airbone and cause harm to those living in the home. Note that all seams on fiberglass ducts need to be precisely sealed and quality cutting tools should be used for all penetrations in the ductboard.

Flex Ductwork

Flex ductwork are a favorite here at United Air Care. These type of ducts should have exteriors that have been approved and verifyed to withstand exposure to UV light. Typically, specialists will use an exterior reinforced with fiber scrim. The only issue with flex ductwork is the restricted air flow, due to convoluted interior surfaces. As long as the specialist accounts for this in the system design, there should be no serious issues. Note that flex ducts should be insulated to a R-6 rating (at least) and must include a reflective outer surface.

You may wonder why it is important to have insulated flex ducts in your home. Does this type of duct make a difference vs. standard ducting? The ducts United Air Care uses are UL181 listed, contain an R-Value of 6 and come with a 10 year warranty. Why insulated duct? The insulation in the ducting will prevent condensation from forming on the duct. Condensation forming on the duct is not a good thing. Another benefit of the insulated flexible ducting is that it further reduces any “air noise” caused by the exhaust fan, so your ventilation system works even quieter.

This natural mineral, drawn from serpentine rock, stands up to intense temperature. Prior to its toxic waste status, its outstanding resistance to heat, combined with its fibrous makeup and low cost, ushered it into the manufacture of thousands of products from toasters to ductwork for more than 60 years.