This week Reggie’s Home has been focusing on what systems we could use to make the Alabama climate feel more thermally comfortable. Reggie does not want A/C in his new home which means our design has to focus on heating and cooling using passive methods. While considering what passive strategies to use it has been important for us to keep in mind that although the summer can get very hot, Alabama is actually a heating climate. This means that there are more days in which spaces would need to be heated rather than cooled. So far we have been researching cooling with simple methods like cross ventilation, the use of a fan, and using a dehumidifier. In terms of heating we’ve been looking at how we could use earth tubes and a wood stove.
Diagram of earth tubes in cooling and heating conditions
Earth tubes are tubes that run underground and precondition the temperature of incoming air before it enters the building. In the winter, the ground is warmer than the air, meaning that the air is warmed as it passes through the tubes. In certain climates it is believed that earth tubes can change the temperature of the air up to 68 degrees Fahrenheit. While doing this research one big question always comes up; how do we know it’ll work in our climate? Lucky for us we have been able to gather data from Earth tubes used in our own backyard!
Watercolor done by the 3rd-year team that built the earth tube and solar chimney for the storehouse. 
Installing temperature sensor near earth tube intake
In 2016, a combination of earth tubes and a solar chimney was used as a passive system for the storehouse on Rural Studio’s Morrisette Campus. The exchange was optimized to create a temperature difference of 15 degrees Fahrenheit between the exterior and interior. In order to test if it’s working the way it was designed we placed temperature sensors outside the storehouse and within the tube in the interior of the storehouse. Through the months of December to February we can see that on average the highest temperature change is 6 degrees Fahrenheit.
Data collected in the month of December
Now the question becomes, how much of a difference is 6 degrees Fahrenheit when it is 32 degrees Fahrenheit outside? This leads us to research different methods that could work instead of or in addition to earth tubes. To help with heating we have been exploring the option of a wood stove which would work as a constant space heater within the home. If placed correctly, a wood stove would be more than enough to heat the entire home.
Diagram of a wood stove in cooling and heating conditions
This coming week we will continue to move our design forward and use the research of these systems to determine how we can optimize the performance of the home. In the mean time enjoy these pictures of the team incase you forgot what we looked like!
Mar 
Jon 
Ash 
Zak
Until next time,
Reggie’s Home