Heating and cooling your log home
Needless to say, our ancestors did not care too much about heating their log cabins. The large fireplaces had no problem heating one or two rooms they lived in. Of course, now that log houses are the size of a family, people are often under the impression that there is something different in the way they are heated, and the good news is that a standard system will work just as well in a house. of logs as in a traditional structure.
Almost all log houses are built with at least one fireplace. Initially, we thought our beautiful soapstone wood stove would heat the entire house, and we would use our forced air propane heat as a backup. Unfortunately, we were all wrong. Because we have a cathedral ceiling with a large loft, the heat from the stove goes directly upstairs, requiring two ceiling fans to recirculate the hot air. We expected this, but we also thought that the heat would spread laterally to the rest of the open space (dining room and kitchen). Not in your life! Even sitting on the couch about five meters from the stove, I need a quilt. I have an uncomfortable cold in the kitchen. I think if we had a regular roof the heat might have gone where we expected it to, but the volume of the cathedral ceiling threw our calculations. Also, the soapstone stove is designed to operate 24/7, and since we both work for a living, the stove doesn’t turn on until late at night. This wood stove needs to be heated slowly to risk breaking the stone, so when you’re actually cooking we’re ready to go to bed.
Old fashioned fireplaces traditionally sucked in all the hot air in the room, but modern designs are more efficient at recirculating heat. The most energy efficient fireplace is built in the center of the house, so the heat from the fireplace is not lost to the outside. Outdoor fireplaces can create drafts if the fire goes out, making it more difficult to start a new fire. If you are planning multiple fireplaces, placing two of them one behind the other (in front of adjoining rooms) will give you the opportunity to build a fireplace with two flue pipes. Or you can place a chimney over your furnace, again allowing two ducts in the same chimney. A direct vent chimney will remove the chimney, but you will have to figure out how to hide the vent in the exterior wall. Or, if you use a wood stove, you can run the pipe through the wall and straight out, building a box around the pipe to simulate a fireplace. Depending on the look you want, you may want to leave the pipe inside the room and send it through the ceiling. This will give it more heat.
It’s a good idea to consider your heating and cooling needs early in the design phase. Although log homes are naturally energy efficient, skimping on your system is not advisable. You may be able to heat your entire home with a large fireplace or wood stove, but the municipality likely has minimum standards to meet before issuing a building permit. Also, you must consider the resale value. I know of one person who tried to sell a million dollar handmade log home without an oven, and presumably the buyer never came. The house was listed as unfinished and installing the heating system after the fact was too daunting a task. There is a similar problem if you try to escape without central air conditioning. Yes, log homes stay cooler in the summer, but those August “dog days” can give you an absolutely miserable night’s sleep, and a potential buyer will likely not be as tolerant as the original owner. In fact, our mortgage company wouldn’t consider making a construction loan if we didn’t include central air conditioning.
If you want to preserve duct space, you can use forced air heat, with the same ducts that serve the air conditioner. Propane or oil are often the fuels of choice in rural areas. If your interior wall space is limited, there are companies that specialize in very small high pressure duct systems that fit into tight angles; these systems generally require a much higher initial installation cost. When using traditional ductwork, you want to keep angles to a minimum, so it’s helpful to design the first floor walls that will conveniently bring air to the second floor. An open floor plan offers a challenge, because you have to keep in mind that the rooms above must be heated in some way, and you will need supply and return vents to create efficient airflow. If you want to use full log interior walls, you will need to find another way to run the ductwork, electrical, and plumbing. We made that mistake and there are not enough vents in our bedroom. The air is stifling in the summer, even with the windows open.
Where do the vents go? Since all of our exterior walls are lined with logs, many of our vents were placed in the floor. If your interior walls are plaster or tongue and groove, you can place the vents where they normally go. One thing I wish I had done was go over the plan with the HVAC contractor, because he put the vents in the places I found the most inconvenience. Sometimes it can be avoided and sometimes it cannot.
If you are concerned about energy and prefer to leave your thermostat all the way down, you will find that the south side of the log home tends to be warmer than the north side. Because the sun tends to sink closer to the horizon on a winter afternoon, it is advantageous to place your large windows facing south; During the summer, the sun will pass through the roof, so it won’t overheat your home. However, you may find that the north side of your home, which will not get direct sun at all, could be noticeably cooler. The best solution is to install underfloor heating (if you can afford it). Although this system requires a boiler rather than an oven, floor heating distributes heat evenly throughout the home, eliminating north-facing blues. With underfloor heating, you need to keep the thermostat steady all the time; the system is not designed to shut down when you go to work. Additionally, you can also use the boiler to heat hot water, eliminating the need for a water heater. On the other hand, you will still need to install ducts for the air conditioning.
In general, the same considerations apply as in normal construction. We thought we could get by with just one heating and cooling zone, but in hindsight, two zones would have solved a lot of problems. In the long run, it’s cheaper to get it right in the first place. Retrofitting a log house won’t be easy!