Ducting belongs to the part of HVAC systems, it plays an important role in distributing cooled or heated air throughout the building. With the proper installation of the HVAC system, you can improve indoor air quality and work efficiency. As we know, ducts are often installed in attics or some unconditioned spaces where the temperature is different from that air transferred in the ducts. The differences in temperature can affect the air conveying through the ducts and it may increase the air conditioning costs. The application of insulation for ductwork can improve indoor comfort, reduce space heating and cooling energy costs. There are two main types of ductwork which are flexible ductwork and rigid ductwork. Each type of ductwork has its own advantages and disadvantages. You should choose the right ductwork based on the HVAC requirements and professional advice from HVAC experts.
Flexible Ductwork & Rigid Ductwork
Flexible ducts are round tubes made up of steel spring coil covered in thick yet flexible plastic. This type of air duct is easier to install and can be installed in tight spaces due to its high flexibility. Additionally, because flexible ducts are made of plastic that is resistant to rust, mold and no dangerous particle are released into the air, the quality of air is able to stay clean over a long period of time. However, flexible ducts are susceptible to bends which may restrict the airflow and affect the efficiency of the HVAC system. They are also more likely to be punctured than rigid ductwork.
Rigid ducts can be either cylindrical or rectangular. They can be made of different materials and are available in different sizes. There are three main types of rigid ductwork, including sheet metal ducts, fiberboard ducts, and fiberglass lined ducts. Unlike flexible ducts, rigid ducts do not have the risk of bends restricting airflow and are unlikely to be punctured or torn. Rigid ducts are not suitable to be installed in tight and tricky spaces.
Benefits of Duct Insulation
When using the metal ductwork, you can expect a lot of sounds that come from it. Duct insulation with acoustical properties can help to absorb these operational noises and minimize the transferring of sound. This can greatly improve the environment and reduce sound pollution. Besides, the HVAC system handles the heating and air conditioning directly, by adding thermal insulation to the ductwork, you can see the improvement in temperature control and reduction in energy loss. This type of insulation also helps to keep the moisture and condensation away from the system during humid climates. A proper installation of duct insulation helps the HVAC system work efficiently and reduce your electricity bill in a long run.
Types of Duct Insulation
Insulation can be put on the internal surface or external surface of ducts. The insulation pasted inside the ductwork is good at suppressing noise, while the insulation put outside of the ducts can prevent energy loss and condensation. Both have different specifications and some are not suitable to apply on the internal duct surface. It is recommended to use insulation with an R-value (insulation values) of 6 or higher to insulate the ductwork.
Duct Board: Duct board is one of the most common types of insulation for the outer and inner layers of the ducts. It comes in a wide variety of R-values.
Duct Liner: It is used to line inside of the duct and is also available in various material and R values. Normally come in large roll forms,
Duct Wrap: It is used to be applied on the outer of ductwork that helps to increase the efficiency of the HVAC system and has better control the condensation. The available material ranges from bubble wrap to fiberglass.
Types of Insulation Materials
1. Fiberglass
Fiberglass is the most common insulation material for insulating heating and cooling ducts. It is available in various thicknesses, R values, and either a rigid or flexible form. The flexible type is in roll form which can be easily installed in the round and rectangular ducts. Normally, the fiberglass insulation incorporates aluminum foil or vinyl coating to prevent moisture that being absorbed by the insulation. In some cases, you also can find fiberglass ducts which ducts themselves are made of this insulation material.
2. Polyethylene
Polyethylene (PE) insulation foam is normally used to insulate exhaust ventilation ducts and air conditioning ducts, it is more preferred to be used for where the duct is exposed. When compared to fiberglass-insulated ducts, PE is more expensive. But it tends to be more appealing as they don’t have the wrinkled surface like what fiberglass looks. It is also safer to work with PE insulation.
3. Rockwool / Stone wool
Rockwool is a common sound-insulating material installed on the internal surface of the ducts to absorb noise. It is made of recyclable material and has better soundproofing when compared to fiberglass insulation. However, the cost is more expensive. Even fiberglass has a similar specification as rockwool and can be used to replace rockwool, but rockwool is still a preferred choice for applying inside the ducts as it won’t tear off easily with a strong wind speed inside the ductwork.
There are other types of insulation material available for ductwork. Choosing the right ductwork and insulation material can improve the efficiency of your HVAC system. MecHero hardware stores supply a wide range of ducting and duct insulation that meet your requirement. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for an inquiry about HVAC sysyem in Malaysia. As a steel and online hardware store in Malaysia, we also supply a wide range of steel materials, general hardware, or mechanical components. Tell us your requirements now and we can advise you accordingly.
Photo credit: kaempfandharris, progressivematerials