Air ducts are one of the most important units in all household or commercial areas. They are the pipes that carry conditioned air (hot or cold) from the AC unit to the room. It also takes the stale air from your room and sends it to the cooling unit for cooling and ventilating it with fresh air from outside. Ducts also have air filter fitted in them to screen the air of all aerial contaminants such pol lens, allergen smites,dirt,dust,and also mold spores. Some ducts have UV lights to terminate microbial being that get into your room with the air. Air ducts could be of two types active and passive. Ducts are actually passive because they have no moving parts. Active ducts use fans to help move the air. The return duct of a house take sin the room air for cooling and the supply ducts give the cool air form the AC to the rooms. It is very important to have properly insulated ducts without leaks to enable your machine work at the peak of its efficiency. Leaky ducts lose considerable portion of energy and needs to be repaired as soon as possible. Let’stake a look at varioustypes of HVAC ducts:

 Flexible Duct work

These are also called spiral ducts. They are made of a wire coil covered with a bendable, durable plastic, and are wrapped with insulation.They are very popular because of their aesthetic appeal. The biggest advantage they offer is that they can fit in tricky and limited spaces. However installing them requires a separate set of procedures. Installing them is easy and takes less time. A single professional can work on installing spiral ducts which cuts down your labor cost. However these duct shave to be installed in a way so that there is no snaking, sagging. Kinks, bends, and turns are to be avoided as these reduce airflow and could hamper the efficiency and effectiveness of the air conditioner. The spiral ducts are often hanged with wires. Wires work well with rigid ducts and cannot constrict the cross-section of hard pipes. But when you use wire on flex ducts it constrict sits cross-section, where it is tied for hanging the pipe. This constriction creates an extra bump for the flowing air inside. To support flex duct properly, use straps that are at least 1.5 inches wide.

 Rigid Duct work

Rigid ducts have been around since long. They are made of different materials and come in various sizes. The can be either cylindrical or rectangular. They are also often insulated. They are surely more durable, hard, and enduring than spiral ducts. They have more weight and installing them requires time and lots of detailing. Here we will take look at various types of rigid ducts-

 Sheet metal ducts

If you are a movie buff, you could not have missed the sight of these ducts. In Hollywood action thrillers, you will often see the hero crawling through these metallic ducts to chase the villain. Sheet metal ducts are commonly made of galvanized steel and aluminum. Aluminum is more popular than galvanized steel as it is lighter and easy to install. The main advantage of sheet metal duct is that it does not harbor dangerous molds because it has non-porous surface.However, they cannot fit in limited spaces. Your ducts will need to be appropriately sized in order to match the heating and cooling system. That way, you can be sure to have excellent performance and energy efficiency.

 Fiberglass lined ducts

These are sheet metal ducts too, the type discussed already. But they have an internal fiberglass lining. Some of the type may have both internal and external lining of fiberglass. You will commonly find these ducts in offices and commercial areas. A lining of fiberglass helps these ducts dampen the sound of the air conditioner unit.

 However, there are some major disadvantages of fiberglass ducts. When these ducts deteriorate after years of use, they release fiberglass particles into the air. This can give rise to many health hazards with long-term exposure. It is difficult clean fiberglass lining as improper cleaning can damage the lining. These ducts can also become contaminated with molds and bacteria. These ducts are always recommended for replacements rather than repair.

 Fiberboard ducts

These ducts are made of fiberglass strands. These are compacted and bonded with a resin and then wrapped with a sheet of foil laminate to protect them from moisture. This type of duct is good for cooling and heating systems because it is well insulated by itself. The major disadvantage this duct is that it is not good or ventilation purposes. They get easily affected with microbial growth like mold and mildew in humid climates. Once affected, they are better replaced. Cleaning and wiping these ducts will not bring much result. Having rough surfaces, these ducts also do not allow smooth flow of air. If your ducts are made of fiberglass duct board or insulated internally with fiberglass duct liner, then follow the recommendations of North American Insulation Manufacturers Association's (NAIMA) to maintain them.