When air needs to move around a heating, ventilation, and air conditioning (HVAC) system, it’s ductwork that moves it. The ducting takes up air, heats or cools it, and puts it back at the right temperature. If necessary, it moves exhaust out of the system. Ductwork can be oval, rectangular or round and it comes in a number of different materials, including flexible plastics, alloys and fibreglass.
Ductwork is easy to forget about because we take it for granted as just part of a building’s infrastructure. However, unless it’s maintained well, it can develop faults and its ability to deliver clean air at the right temperature can be compromised.
When ducts leak, they can lose up to 35% of the air in the system with the result that more air needs to be drawn in and heated or cooled – http://www.greenhomeguide.com/askapro/question/how-do-you-seal-leaky-ductwork. Causes of leaky ducts include holes, joints that haven’t been sealed properly and connections that have been put together too loosely. While it’s fairly straightforward to find out whether it’s the supply or return that is leaking, it’s more difficult to locate the leak. A specialist HVAC contractor often needs to find the source of the leak by testing the air flow through the system.
A ductwork blast gate damper https://www.dustspares.co.uk/Blast-Gate-Damper.html needs to be made of robust enough material to operate without leaking. So materials such as cast aluminium are preferable. The shut-off blade that closes the damper may be steel coated with zinc for leak-free operation.
Flexible ducting can easily flex in a way that causes leaks. If it has kinks or is crushed or twisted, it will have trouble moving the air through the ducting, and airflow will, therefore, become restricted. So this kind of ductwork needs checking regularly.
Unfortunately, some pests can see ductwork as a nice warm (or in summer, cool) place to take up residence. The range of pests found in ductwork ranges from mice to wasps – cleaning and maintenance should make this kind of infestation much less likely.
There’s a huge difference in efficiency between a well-designed system, and one that is not properly thought out. So give the ductwork design brief to a professional. Then make sure that you use an installer who has been recommended by other clients.