High efficiency furnaces and central air conditioning units do increase the overall efficiency of a home. But replacing your furnace or air conditioner may not be as efficient a purchase as you may think. If your ductwork has holes, or the seams are not sealed, you are losing a significant amount of air through these areas. Sealing these areas could increase the efficiency of your entire HVAC system without the costly upgrades in new equipment, read more from here. There are a few different sealing methods for increasing the efficiency of your HVAC system.
Using duct mastic around the horizontal seams of the supply ductwork is important in keeping the air that is being distributed throughout the house inside the duct work. Wrap the seams with a mesh tape and apply the pre-mixed duct mastic with your hands. Wear a rubber glove and be generous. The mastic should be smoothed out over the tape and should go all around the duct seams. The duct mastic takes about an hour to dry. At that time the HVAC system can be turned back on.
Duct tape has a metallic backing with a peel and stick surface that adheres to the ductwork. In order for the duct tape to adhere properly to the duct work, the ductwork must be free of dust and debris. Wipe the area down with a damp, clean cloth and wrap the tape around the duct seams. Use a small piece of wood to push along the taped seam to make sure that the tape has fully adhered. This is good for harder to reach areas.
Closed Cell Spray Foam
Using closed cell spray foam seals the seams of the ductwork completely and adds rigidity to the ductwork itself. The surface of the ductwork must be free of any dust or debris before spraying the foam onto the ductwork. Use a piece of cardboard in back of the area you are spraying to prevent overspray from going everywhere.
One of the major benefits to this method is that it is easy to apply and will also insulate the ductwork if you choose to insulate the supply duct lines. This can add enormous efficiency, especially in crawlspaces.
Health and Sanitation
One aspect of duct sealing that is rarely discussed is the health and sanitation aspect of the duct work. Seams and gaps allow insects and rodents to enter your ductwork and can create a major sanitation issue. Sealing the ductwork keeps these creatures from entering your ductwork and keeps the ductwork cleaner. Duct cleaning is a recommended practice by the Environmental Protection Agency for optimal indoor air quality.
Before you invest in a high efficiency furnace or air conditioner, seal your ductwork properly. Not sealing your ductwork will not create nearly as much efficiency, even with new equipment.