How to Seal Ventilation Ducts? Which Is the Most Used Duct Sealant?

Every HVAC system has its flaws. It is near impossible to build a system from the ground up without having any leaks. Even if you seal the leaks right after first testing the system, in time, new leaks can form and drop the performance significantly. In residential uses (HVAC systems for indoor climate control) the leaks could cause 20% to 30% of a drop in performance. This makes the temperature control in your home a hard task. No matter how you set your thermostat, the result won’t be quite near that figure.

Leaks in ductwork result in higher energy bills because it makes the heating/cooling core of your system work twice as hard. No one wants higher bills, right? In order to keep that heavy burden at bay, you need to run annual checks of your system and always keep it in good condition. This could save you money in the long term.

For commercial-grade systems, things are a bit more serious. Once again, leaks in commercial-grade ductwork lead to energy losses. The bad thing is that the costs are far bigger and can even result in wastage of production (if the cooling system fails) or even harm to employees. Let’s take a fume extraction system for an example. What will happen if you have a leak in your ductwork in a fume extraction system? Well, you can potentially leak toxic fumes in the breathing air of unsuspecting employees or even customers. Not something you want to deal with!

How to seal ductwork and keep everything in check

We have already mentioned that it is best practice to check your HVAC system annually when it comes to residential systems. For commercial-grade systems, it is best to run tests a couple of times per year.

In case any leaks are detected you have to use duct sealing products or repair damage by changing old ductwork elements with new ones. If you execute regular checks, you will most likely catch any problems in their early stages. This means that a quick repair job with a duct seal will be enough.

What is a duct seal

Duct sealants are special compounds designed to fill gaps and cracks in ductwork. Often people think that applying duct tape will be enough. They think they figured it all out, and finally understood why it is called duct tape. Hate to break your bubble, but this is not the case. Any tape product just won’t be efficient, because in time it will lose its adhesiveness and the problem will arise once more.

Quality duct sealing products must be used for such repairs. The most used duct seal is probably the LD410 Duct Sealant. It is a product with outstanding qualities. LD410 is a silicon-based duct seal that could be easily applied with the help of a mastic gun. This sealant will take care of any small cracks and holes. It is also perfect for connection points, where most of the leaks form anyway. If you are repairing a long crack you can apply a line of LD410, and push it in place with the help of a plastic spatula or your finger (ALWAYS WEAR GLOVES). After the sealant is in place you can additionally secure it using some fabric mesh. The mesh will stick to the sealant and will make the joint more flexible. You can even cover it all up with tin tape or strong construction grade tape. In time the tape may fall off, but the seal will be well protected. By then, all you would need to do is to apply a fresh layer of tape on top to keep condensation and other elements away. You can find tapes and gaskets on our product page.

You can learn more information about the different options on the duct sealant category page. If you still have any questions the professionals by the phone: 01455 616444 will gladly assist you in choosing the right product for you and can even give some additional guidance.