If you heat your home using hot air blown through ducts then chances are you’ll need a system of hot air control using dampers for ductwork. The reason for this is quite straightforward in that from the source of the hot air, the temperature and pressure at which it is pushed into the ductwork system will be very high, but they might not be the levels at which you want it to enter all of the different rooms. To get around this, a series of Volume Control Dampers (VCD) can be deployed inside the ductwork to give manual or automatic control of the air flow.
With the hot air system also requiring external ventilation there is always a risk of a blow-back - blowing cold air from the outside into the hot air ducts. The risk of this too can be eliminated by installing dampers for ductwork.
Before beginning to install the ductwork dampers make sure the inside of the ductwork is thoroughly clean using brushes or a vacuum system. If you leave any dust in the ductwork it will impair the performance of the dampers and, for automatic ones, could ultimately lead to their premature failure. With the inside of the duct clean you can start fitting the dampers.
Consult the ductwork manufacturer for help in making sure you buy the correct damping components, if no manual or information is available carefully measure the diameter of the ductwork and ask your local or online DIY store which ductwork dampers they would recommend for that diameter and material that your ductwork is made from.
Remember dampers can be entirely manually controlled, control by time, temperature or time and temperature. If you’re fitting an automated damper you’ll need to access a power supply at some point, so check your local building regulations if you’re not a qualified electrician. Remember as well you’ll probably be wiring inside a metal duct, so be sure the power is shut off completely to that locality.
After gaining access to the ductwork you’ll need to drill holes that will line up with the holes in the damper frame. All you then need to do is fix the screws through the ductwork into the frame, fit the damper back into the frame and seal the screw holes on the outside of the ductwork with duct tape.
Adjusting Ductwork Dampers
One reason for fitting the ductwork dampers was probably to save money by not wasting energy unnecessarily. So, to make the dampers pay, if they’re manual ones, you need to remember to open and close them so as to make sure the air flow is directed into the rooms when it is most needed.
If they’re automatic dampers, you’ll need to do a bit of experimenting so that they are set to heat rooms according to their usual occupancy, rather than being on full all day long. This doesn’t just apply to seasons of the year either, with them closing off the air supply in warm weather and opening them up in cold weather.
For example, bedroom air duct dampers can be set to be ‘on’ for an hour or so before the time you normally go to bed and then to be altered to remain open at a lower temperature setting through the night.