Hi,
My daughter’s house has 9 heating vents in the open living/dining/kitchen/entry area, with the furnace directly under the living room. No heat gets to the bedrooms at the far other end of the house. I blocked off 7 of the 9 registers in the open area and solved the problem, but now I am beginning to worry about building up back pressure at the furnace, since there are so few vents open. Is there any way to check or see if there is a problem?
Are there any other good ideas in general for solving this common problem. The commom open area still gets heated ok, but some of the windows are condensating because the vent under them is closed off.
Thanks
Replies
IF the installation was done by a competent professional, there will be volume dampers at each supply branch. Look at the ductwork, if it is accessible, that supplies each of the registers in the living/dining/kitchen/entry area and see if there are volume dampers in the ducts. These are recognizable by the little (about 3") handles on the outside of the duct. These can be adjusted to regulate air flow through them to balance the system, such that the air goes where it is needed not just through "the path of least resistance". Else, see if the "vents" are grilles or registers. The difference is that registers have a damper included, behind the grille. These also can be used to adjust air flow as necessary.
Don't worry about the backpressure. The furnace will stop working if the flow through it is too low. Besides, it sounds like you diverted flow, not elimininated it.
Thanks,
Mostly I didn't want to screw anything up while I experimented. There are louvered registers but no volume controls. Now that I have established heat to the bedrooms I am unblocking the ducts to see how much air can go to the open area before the bedrooms lose their heat.
Thanks again
Like Tim says, a really good heating system would have dampers in the ducting to allow for balancing the system. Since most residential systems don't have them, the next best thing would be adjusting the heat registars. Very generally speaking, the registars farthest from the furnace (i.e. longest duct runs) should be wide open and the closest registars can be partially closed. I wouldn't "block" or completely close any registar.
Even heating throughout the house can also depend on whether the interior doors are open or closed, the location of the thermostat, and the location of the cold air return.
Make sure you're dealing with registars and not grills. Registars are inexpensive and come in standard sizes. Then, I would "unblock" those seven registars and star fiddling with the adjustments. If that doesn't work, you may need some help from a heating contractor.
good advice to check dampers first
if they check out fine then the next step is check proper fan operation, could be very dirty fan blades, this would account for some efficiency drop also some fans have multispeed settings that are not set or operational
if the fan is clean and working to spec then the penultimate option is to install booster fans into the ducts that have the reduced flow, rheostats can fine tune the flow rates so each fan will flow the correct amount, these can be wired to automatically turn on via relay when hvac fan is on, can be turned off in cooling system if need be..
last option is new hvac system
did the house with current system EVER work properly (heat bedrooms)?