A couple of rooms in our house are too hot in the summer and too cold in the winter. Without installing an expensive zoning system, how can we make those rooms more comfortable?—Scott W.
This is not only a comfort problem, but often a costly one. When one or two rooms are too warm or cold, people usually change the thermostat setting. Each degree you raise the setting during the winter or lower it during the summer can increase your utility bills 1-3 percent.
First, try to determine why those rooms are not the same temperature as the rest of the house. Hold a thermometer in the airflow from a register and compare it to the register air in the comfortable rooms. Also, hold your hand over the register to feel if the airflow is equally strong as that in the other rooms.
If the register outlet air temperature is warmer in summer or cooler in winter than other rooms, but as forceful, you may need to insulate those ducts. They are likely longer ducts farther from the furnace and may not be insulated from the outside walls or attic.
If you find the airflow is not as strong, make sure the dampers in the ducts are fully open. It would be a good idea to wrap foil duct tape around all the duct joints.
Partially close the dampers in the ducts leading to the comfortable rooms. This will force more conditioned air to the problem rooms. Don’t close the dampers more than halfway because you don’t want to excessively increase the airflow resistance for the blower.
It is not difficult to install duct dampers if your existing ductwork does not have them. Another option is to install new register covers with adjustable louvers. This is more expensive than installing duct dampers, but the real wood and cast metal registers can be very attractive.
If the problem still exists, consider installing booster fans to force more conditioned air to those rooms. These are made to fit almost any round or rectangular duct and are easy to install. These fans use as little as 20 watts of electricity, so they are inexpensive to operate.
Whenever the main blower starts, the booster fans also run. The on/off switches can be wired to the blower control in the furnace or heat pump to operate the fans. It can be tricky to wire several of them this way, so professional installation of the wiring would be advisable.
A simpler setup for do-it-yourselfers uses a pressure or sail switch. A sail switch is a lightweight plastic sail on a hinged wire, installed in a small hole in the duct. The airflow from the blower moves the sail and triggers the switch. A pressure switch is even smaller, and it senses the pressure change when the blower starts to switch on the booster fans.
Another option is a quiet booster fan (Equalizer II by Suncourt) mounted over the top of the room floor or wall register and plugged into a standard electrical wall outlet. It uses only 27 watts of electricity. In addition to drawing more conditioned air through the duct into the room, the fins on its grille help to distribute the air in a more even pattern throughout the room.
If one warm room has a common wall with a cool room, install a through-the-wall fan. It moves enough air to help balance out the room temperature differences.
The following companies offer registers and booster fans: Aero-Flo Industries (219-393-3555, www.aero-flo.com), American Metal Products (800-669-3269, www.americanmetalproducts.com), Deflecto Corporation (800-428-4328, www.deflecto.com), Field Controls (252-522-3031, www.fieldcontrols.com), and Suncourt Manufacturing (800-999-3267, www.suncourt.com).
Mail requests and questions to James Dulley, Kentucky Living, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit visit www.dulley.com.