The Importance of Having Insulation in Your Ductwork
Typical HVAC Ductwork
Ductwork insulation is important because it ensures that the air traveling through the ductwork will stay at the desired temperature and that the air won't "leak" out. If the air is leaking out then there is unnecessary energy loss, which means that your HVAC system will have to work even harder to deliver the air you want into your home. This will cause higher energy bills as a result of wasted energy, which is not good for you or the environment. In other words, without proper ductwork insulation, the air in the ducts will quickly cool off, and instead of heating your home, the ducts will blow out cold air. Without proper ductwork insulation, it's estimated that you could be losing 10-30% of the energy used to heat or cool your home. A good level of ductwork insulation can prevent this, as well as leaks, temperature drops and condensation buildup. HVAC contractors recommend that ductwork insulation have an R-value of at least 5. Read more about R-values for ductwork.
What are air ducts/ductwork?
Ducts are often made of thin material, which is why it is so easy for the air traveling through them to be lost. Proper insulation will ensure that the regulated temperature will be maintained as the air makes its way to your living areas. The ductwork in unconditioned areas, such as basements, floors and ceilings is where ductwork insulation is most necessary.
Ductwork Insulation Prevents Condensation
Proper insulation levels can actually prevent condensation form occurring in your ductwork. Cool air passing through warm areas in your home can cause condensation in the ductwork. Cool air is a result of poor ductwork insulation, and moisture can lead to all sorts of problems such as mold and mildew growth.
Seal Ducts Before Insulating
Before adding ductwork insulation, it is highly recommended to first seal leaks in the ductwork. Contact an HVAC contractor to seal the ductwork, specifically all of the points in the duct run. The proper way to seal is to use a material called mastic that is brushed on and then left to dry for about a day. Mastic is used because it does not deteriorate or shrink away from the joints. Keep in mind that duct tape should not be used for sealing ductwork, as it could deteriorate and decompose and cease to be effective to seal the leaks, leaving you with a sticky, useless mess on the ductwork itself.
Types of Ductwork Insulation
The most common ductwork insulation material is fiberglass. A newer and more effective option is duct wrap, such as Reflectix.
Fiberglass Insulation:
- Used to line ducts
- Cost-effective
- Easy to install
- Easy to replace
- Absorbs noise
- Needs to be inspected often for any moisture absorption
- Comes in 1 or 2 inch thickness
Reflectix (Duct Wrap):
- Very efficient and stable
- Lightweight
- Made up of foil faces on the outside that hold bubble pack between layers of polyethylene
- Is much thicker than fiberglass wrap; Reflectix is available in under 1 inch with seven insulating layers
- Has an R-value of 5.6
- No risk of moisture problems as with fiberglass
Remember: The key to successful ductwork insulation is having a professional, experienced HVAC contractor install it for you.
