Calibrate and Graduate

Team is posing with their new outfit

Exciting things have been happening at HomeLab lately! First, the Thermal Mass and Buoyancy Ventilation Research Project (TMBVRP) Team were able to install airflow sensors into the Concrete Chimney Experiment. Second, the chimney has brought in some impressive data. And third, the TMBVRP team participated in an end of the semester presentation and round table discussion with their big sister team, the Mass Timber Breathing Wall Research Project, and a cast of professionals in the architecture and building science research field.

This week the team received their Sensirion differential pressure air flow sensors. The sensors record a difference in dynamic and static pressure which the team uses to calculate bulk flow. Bulk flow is the total airflow at the sensor location. The team installed two sensors into the Concrete Chimney Experiment, one at the bottom and one at the top, to measure updraft and downdraft ventilation created by the thermal mass.

Just to refresh your memory, updraft occurs during the night when the cool, night air is brought in the bottom ventilation opening, warmed by the thermal mass, and exhausted out the top. Downdraft occurs during the day, the warm, exterior air is drawn into the top ventilation opening, is cooled by offloading heat to the thermal mass,  and vents out the bottom.  Being able to measure the direction and amount of ventilation is critical to understand if the Concrete Chimney Experiment is performing as expected.

And the results are in, our initial measurements from the airflow sensors do show that during the day the chimney is operating in downdraft and during the night it operates in updraft. This gives us proof of concept, that thermal mass is able to alter the atmosphere inside the chimney so that it goes against the exterior environment.

graph showing airflow in the test chimney

The GreenTeg temperature sensors have also brought in proof of concept data, showing that the thermal mass is having a damping effect on the interior air. It is important that the temperatures of the thermal mass and interior air cycle with the daily swing in temperature so that heat is absorbed by the mass during the day and offloaded during the night. This shows that the internal thermal mass is effectively moderating the temperature in the chimney and causing continuous ventilation. We are continuing our testing to further calibrate the amount of ventilation to achieve the most efficient and effective heat transfer between the internal thermal mass and air.

Temperature signal graph comparison

To wrap up our undergraduate work, we had a roundtable presentation via Zoom to give an update on where our work is and share our exciting results with Auburn, our collaborators at McGill, and professionals in the architecture and building science research field.  This panel included Billie Faircloth, a partner and research director at the architecture firm Kieran Timberlake in Philadelphia, PA.  Second, we were joined by Jonathan Grinham, who is a Lecturer in Architecture and Research Associate at the Harvard University Graduate School of Design.  Last but not least, is Z Smith.  Z is a Principal and the Director of Sustainability & Performance at Eskew Dumez Ripple in New Orleans, LA.  

It was a privilege to be able to present and have a productive discussion with such esteemed professionals.  We gained valuable insight on how to best relay the work we are doing do both those in the research field and the common person. In addition, their backgrounds led to an intriguing discussion on how The Optimal Tuning Strategy could be implemented at the building scale. It was especially awesome to discuss the successful data the team recently got form the Concrete Chimney Experiment. Both the data and the discussion gave the Thermal Mass and Buoyancy Ventilation Research Project Team a boost of confidence and pride in their work. It not always easy for these architecture students to wrap their heads around the science, but the hard work paid off. Thank you to Rural Studio, Salmaan Craig, Kiel Moe, David Kennedy, and the reviewers for a positive end of the undergraduate phase of the Thermal Mass and Buoyancy Ventilation Research Project.

Final shout out to the incredible Mass Timber Breathing Wall Research Project Team. As they complete the paper on their research and graduate from the Master’s program they still had time to do something very sweet for their little sister team. They passed along their Rural Studio lab coats, crossing out their names and writing the names of the TMBVRP team members. Their work, dedication, and attitude could not be a better example for the TMBVRP team to emulate. From one research project team to the other, thank you for helping us whenever we needed and being the best big sister team imaginable. We hope to live up the legacy! Well, everyone, stay tuned (optimally tuned) this summer for the start of the graduate program at HomeLab.