Dear Jim: Some rooms in our house are too hot or too cold, and someone is always complaining. What can we do to even out the room temperatures to keep everyone happy. Will doing this lower our utility bills? – Sean H.
Dear Sean: There probably is not one house in the entire country that has even temperatures throughout all the rooms. There are many factors such as the length of duct, bends, orientation to the sun, number of windows and exterior walls, etc., that affect the room air temperature.
Actually, it is not desirable to have all the rooms the same temperature. Depending upon the activity level in the room, a range of temperatures may be comfortable. Also, some people just like it warmer or cooler.
The simplest method to control temperatures in various rooms is to adjust the dampers in the furnace ducts leading to the rooms. Somewhere near the furnace, find a small handle on the side of each duct. When the handle is parallel to the duct, the damper is typically open.
During winter, partly close the damper in the ducts leading to rooms that are too warm and make sure the other ones are totally opened.
You may find you must close them pretty much to affect the room temperature. Wait several hours for the room temperature to stabilize between adjustments.
Mark the damper handle locations on the ducts with a W for winter. During summer, the damper adjustments will have to be changed. For example, a room which gets much sun during winter may need less warm air to be comfortable. During summer, that room will be too hot and need extra cooled air.
Installing an automatic zone control system is the best and most energy-efficient method to control individual room temperatures. Instead of your manually adjusting the duct dampers, a zone-control system adjusts special dampers based upon the actual room temperatures and what you desire.
Many houses have access to only several main ducts that later branch out to the individual rooms. In this case, the zone control system will control the temperatures in each room grouping, such as all the bedrooms.
A programmable thermostat is mounted in each room to control the motorized duct damper leading it. If the room is too warm during winter, the damper partly closes.
For example, a thermostat may continuously readjust the damper as the intensity of the sun through a window changes throughout the day.
The majority of the energy savings is realized because each room temperature can be varied throughout the day. There is no need to keep the bedrooms toasty warm during the daytime or the living room warm overnight.
A cooler room loses less heat through the walls, so the furnace runs less.
Dear Jim: We have a cathedral ceiling in our living room. There is only a small gap between the ceiling insulation and the underside of the roof. Would this be a good application for a solar attic fan? - Tom S.
Dear Tom: You are lucky there even is a small gap for ventilation above the insulation. It is important to ventilate away any moisture which passes through the ceiling drywall during winter or keep it cool during summer.
This is an ideal application of a solar attic fan. With just a small gap, a huge amount of air flow is not needed. Also, a solar fan needs no electric wiring which may be difficult to run with a finished cathedral ceiling.