Harp on the Furnace

I know that I wrote a couple earlier blogs on winter heating (something about freezing my wazoo), but hey, it’s January, it’s cold and I can’t very well be writing about gardening or fishing, can I? So bear with me.

To prepare for ole man winter, I’ve weather striped the front door, put a bail of straw against the rear crawl space entrance, put light bulbs by the water pipes in the crawl space and in the pump house, insulated the top side of the attic entrance, and opened the exterior clean-out door on the old woodstove chimney so that it will draw from the outside and not the house interior. We reset the thermostat during the day based on our needs; I’m not going to overheat the house when we are not in it.

I’ve noticed that when the thermostat is set at 70 degrees or higher, the furnace kicks in very frequently and seems to struggle to keep the house warm; at 60 degrees, it kicks in much less. I think this is because the house maintains a natural level of residual heat from the fridge and freezer, from cooking, from radiant sunlight through the windows, and from the body heat of the occupants which make the 60 degree setting a much easier task. Since I have worked outdoors most of my life and know how to dress warmly and comfortably in light layers, I turn down the thermostat each morning after my wife leaves for work. The rule of thumb is that turning down the heat one degree reduces the fuel consumed 1% to 3%.

The natural comfort zone is between 70 degrees and 85 degrees, but this can be easily extended by ten degrees on either end. A wind chill from a fan can make us feel cooler in summer so that central air conditioning does not need to be used until 95 degrees. A fan uses as little as 1/40th the electricity that a central air unit does. Humidity retards body cooling by slowing skin moisture evaporation, and so can make us feel ten degrees warmer in winter. Most natural gas furnaces burn both humidity and oxygen out of the air, so other means must be found to add moisture to the house, either with a humidifier or by boiling potatoes or rice or simmering soups. Do not use a bathroom exhaust fan in cold weather or all the heat and humidity will be pumped outside in short order. Save the bathroom moisture for the rest of the house. So use a fan in summer and humidity in winter to widen the natural comfort zone.

There are a couple prevalent myths about winter heating:

Myth (1) Closing off rooms and their heating vents saves money. You can close the rooms but don’t close the heating vents. When a furnace is installed in a home it is rated to run efficiently heating the ENTIRE house. If vents are closed, the furnace will work inefficiently as heat backs up and overheats the furnace itself, possibly doing damage to its mechanisms. Better to open the vents, close the doors, and fool the thermostat from kicking the furnace in at all. Keep the room that the thermostat is in warm with a safely operated space heater or from cooking heat or passive solar from a sun porch. Then the closed off rooms become true dead-air insulation buffers without affecting the furnace.

Myth (2) Super insulation will lower your natural gas heating bill. Insulation is good up to a point, but if you are heating with natural gas (not electric, or geothermal, or solar) and the furnace draws its combustion oxygen from inside the house and not from outdoor air, then in an overly tight, super-insulated house, it will burn out so much oxygen that incomplete combustion will cause fuel to be wasted. In other words, the stale air will cause the flame to burn too rich. The inefficient operation of the furnace is similar to having a dirty furnace filter which does not allow it enough air for complete combustion. (By the way, you need to check and change that furnace filter on a regular basis.) The highest efficiency furnaces get their air supply from outdoors which is also healthier for the occupants.

To anyone who feels they can contribute or enlighten on any of the above discussion, I would greatly appreciate your input.

That’s it! …I’m done for the winter. I will not harp on the furnace or winter utility bills again.