research project

The Final Countdown

Exciting news from Hale County: the Breathing Wall Mass Timber Research Project (BWMT) test building construction is complete! Last week Fergie and Preston finalized the construction of two mass timber test buildings on Rural Studio’s campus. These test buildings will be used in the future for research on the breathing wall, thermal mass, and mass timber. The team is also in the peer review process for their scientific paper on their small-scale experiments. It’s been a busy two years!

As a quick update, these two mass timber buildings are the result of two years of design and experimentation on mass timber systems and their potential integration with breathing wall technology.  The floors, walls, and ceilings are all dry-stacked timber compressed with threaded rods to ensure an air-tight envelope. All of the steel components were designed and fabricated to facilitate the BWMT experiment: a steel roof acts an umbrella to protect against solar radiation and wind-driven rain; doors are hung from the top on the exterior to adjust to expanding timber; and steel plates and angles spread pressure from the threaded rods evenly through the timber. On the interior, flexible loft spaces are accompanied by fabricated railings and ladders, with a simple conduit carrying all electrical and lighting. The entire project was designed with flexibility in mind, so they can be used for future experimentation. The goal isn’t that these buildings are precious, but that they’re useful. 

The past two years have definitely been a learning experience – doing scientific research at an architecture school was difficult at times, but the tension between the two really propelled the team and the project. The team learned to leverage the scientific aspect to inform their architectural decisions and to use their architectural knowledge to keep the research grounded. In the end, the design was stronger because it was backed by actual research; science and architecture can and should go together.

The team would like to thank the many reviewers and supporters who helped further this project for the past two years. Thank you to the Rural Studio faculty and staff, particularly Andrew Freear and Steve Long. Thank you to all who donated gifts, materials, and time. Thank you to the team’s studiomates, friends, and family for the constant support. Thank you to the Newbern community for welcoming the team in and taking them under their wings. And huge thank you to Salmaan Craig and Kiel Moe at McGill University and David Kennedy at Auburn University who volunteered their time each week to invest in and further this research. 

Rural Studio is a place filled with magic and the team was extremely thankful to have been a small part of it for the past two years. The team served not only as students but community members, scientists, buildings, chefs, and farmers (to name a few.) They gained an understanding of the importance of being a part of the place and the community.  All four team members are committed to taking what was learned in and out of the classroom forward with them as they move on from Hale County. 

As for the team, Jake has been in New Orleans researching mass timber as a Research Fellow for Eskew+Dumez+Ripple. Anna is pursuing her PhD at McGill University furthering the study of the Breathing Wall. Fergie and Preston are moving to the mountains of Colorado to chase some design-build dreams. The team looks forward to the many visits back to Hale County and Rural Studio. That’s a wrap! 

Not leaving Hale forever,

The Mass Breathers 

Soundtrack: The Final Countdown  |  Europe

Citing, Siting, and Siding; All exciting!

Exciting news, the Thermal Mass and Buoyancy Ventilation Research Project Team have published their Chimney Experiment data onto an online data repository! The team has uploaded data to the Craig Research Group Dataverse through Salmaan Craig at McGill University. Great thanks to the team’s collaborators at McGill, without which this would not be possible.

online data repository interface

The team will continually update and upload data as new data is gathered and past data is analyzed. From there, anyone can download and review the raw and analyzed data for both the concrete and pine experiments. This data is a citable source for any publication investigating the passive cooling strategy. There is also an experiment guide available to download which details the design of the experiments. Using this guide others can replicate or improve upon the experimental setup. This process is great practice for the team as they start writing a scientific paper about their experiments for a peer-reviewed journal. Now for some good ole design talk!

The TMBVRP team decided the experiment is best served as a free-standing structure although they loved utilizing the SuperShed as a super roof and a superstructure. The experiment needs a little extra room to breathe and ventilate than the Supershed can provide. The question remains, where do you place a giant occupiable cooling chimney so it sticks out just enough? Not quite a sore thumb, but definitely not a wallflower.

Along with possible sites for the pods, the team is investigating the use of berms. Why berms? The cooling patio will likely be an excavated area so cool air from the chimneys will sink and collect. This space needs some sort of semi-enclosure to help trap the cool air. Therefore the excavated dirt can create berms, trapping the cool air while providing shade and seating. The berms can also divert water so the cool air pool does not become a catfish pond. The team is analyzing sites in proximity to other pods and Supershed while giving each location a fitting suburb names. Right now they are considering two design schemes: Two Trees and East End.

Two Trees would address the “other side of the street” created by the Supershed and the row of original pods. This site is most appealing due to the natural shade provided by the, you guessed it, two trees. Thanks to team collaborator and Auburn professor, David Kennedy, for introducing the team to shading and solar radiation software. This software, through Rhino, will show exactly how much solar blocking the trees provide. While the trees are a bonus, the water is not. Water from all of Morrisette Campus drains right through Two Trees. This is also why the team has steered away from a site at the west end, the lowest point on campus. At this location, the team also thinks the pods compete with the Supershed in a strange manner. For these reasons, the team decided to take a look at the East End. East End could serve as a continuation or cap to the Supershed. However, there is no hiding from the sun in this location. Thankfully it is more beneficial to the experiment that the pods receive equal solar exposure rather than partial but inconsistent exposure. The team will continue to evaluate both sites.

The team is currently exploring high albedo, ventilated cladding systems. Albedo refers to the amount of energy that is reflected by a surface. A high albedo means the surface reflects most of the solar radiation that hits it and absorbs the rest. A shading or reflective cladding system, when coupled with the use of SIPs, will allow for the interior system to work unaffected by exterior solar heat gain. Metal cladding is an easy way to reflect radiation. A light-colored timber rainscreen can also reflect heat and shade the structure behind it. The team is exploring both options.

The Thermal Mass and Buoyancy Ventilation Research Project Team is also getting into the structure needed to support the pods, 8′ above ground. To start the team looked at a local precedent: silos. In Hale county, silos for holding catfish and cattle feed are aplenty. They can support up to 30 tons with a light-weight steel structure. Steel manual in hand, the team has been investigating how they could apply a similar structure to lift the pods. This allows for an open space beneath for the cooling patio. Next, the team will investigate the possible benefits of using a wood structure.

The team will keep pushing their citing, siting, and siding ventures forward while living it up in Hale County. They’ve been utilizing the great outdoors for grilling and being grilled in reviews. Livia sometimes misses out on the fun as she is dedicated to the landscaping at Morrisette. For more research graduate student shenanigans make sure you stay tuned!

It’s Been Grate

A lot has been happening here on the ground with the Breathing Wall Mass Timber Research Project team. The team said goodbye to Anna Halepaska a few weeks ago as she made her way to McGill University to pursue her PhD in architecture under Salmaan Craig, a main collaborator on this two-year research project. Huge congratulations to her and her future in research! 

Fergie and Preston are here at Rural Studio finishing up the construction of the breathing wall mass timber test buildings. The roof is nearly complete! The majority of the roof metal has been screwed down to the purlins and the two teammates are finishing up the south end this week. The south side acts as a hip roof for water drainage while the north side is an open, angled gable end. 

Last week the team (with the help of a few of our new 5th-years on campus!) poured concrete footings and set the posts for the metal grate walkway. Once the angles were welded to the post, the walkway was put in place. Borrowing a few details from the Perry Lakes projects, the stairs were welded in place to complete the full walkway. Next up, doors! 

Yet again, the team used an older Rural Studio project, Newbern Town Hall, as a precedent for the door detail. The steel angle frame is attached to the exterior wall only at the top while the side clips keep the door frame flush but are not fastened directly to the frame. Wood expands and contracts over time so this detail gives the door an opportunity to expand and contract with the wood, riding up and down the exterior wall along the clips. This also minimizes thermal bridging around the opening. Keep an eye out for the final door install! 

The to-do list is getting shorter by the day. The team will be installing the doors and running the electrical next week to wrap up the construction of both test buildings. Stay tuned for an update on the team’s research paper and the peer review process! 

Getting used to the heat,

The not-always-sweaty massive breathers 

Soundtrack: Closing Time | Semisonic 

Back in Business

The Mass Timber Breathing Wall Research team has been in quarantine for the past several months, but they’ve kept themselves busy. The summer was spent finishing up experiments, carefully documenting data, and finally writing and submitting a paper on their research to a scientific journal for peer review. The team is currently waiting to hear back from the journal, but keep an eye out for a future post with details!

Now that a new semester has begun, the team is back on site (following COVID-safe protocols!) and finishing up the two mass timber test buildings on Morrisette campus. After sitting under a tarp for a few months, the pods needed a little TLC. But one of the benefits of stacked timber construction using threaded rods is the ability to take the building apart again – which is great for test buildings that may need to be altered in the future. The team (plus our volunteer, honorary teammate, and Rural Studio graduate student, Charlie Firestone) unstacked, re-braced, and re-stacked the walls and ceilings for both pods over the course of two weeks.

Once all of the wood was up, steel plates and angles were threaded on along the ceiling and floor to evenly distribute force from the threaded rods. The walls were tightened down, and lag screws driven through the thinner North and South walls to pull the corners tight. A layer of sill seal (a compressible gasket) in all of the joints ensures that any gaps or irregularities are sealed. Finally, a couple coats of spar urethane sealant protects the pine from moisture and mildew.

Switching material palettes for the roof, a steel space-frame spans over and between the two timber ‘boxes’ to support the corrugated metal roof. The team fabricated all of their trusses last year in Birmingham (thanks again to Turnipseed International and the guys at the shop!), so they were ready to go up as soon as the wood was sealed. It was a long morning in the Hale County heat, but with the help of Prof. Steve Long and the Bobcat everything went up smoothly. Purlins were welded in place, and corrugated sheet metal will be going up soon!

Since the days get so hot here in the summer, afternoons have been spent doing prep work for the next day and finishing interior details. The lofts (which are centered over the space to prevent asymmetric airflow) were installed, resting on ledgers which run along the east and west structural walls. Railings and ladders – fabricated from 1” steel tubes – were screwed in place.

The last few tasks are installing the roof metal, doors, a metal grate walkway that runs along the front of the two buildings for access, and lighting and electrical. Stay tuned for updates on the paper, and finishing details on the two test buildings!

Constantly sweating,

The Master Builders

Soundtrack: We’re Still Here | For Giants

Thermal Imagination

Live from HomeLab, it’s time to evaluate our experimental environment! While the Wood Chimney Experiment racks up data, the team is trying to better understand the thermodynamics of their Lab. Of course by “Lab” the Thermal Mass and Bouyancy Ventilation Research Project Team means their carport. Let’s get into it!

Quickly after building the Wood Chimney the team noticed sunlight hitting it’s lower half in the early morning. Although a small amount of morning sunlight will not stop the Optimal Tuning Strategy from cooling and ventilating the Wood Chimney chamber, it creates unequal conditions between experiments. One of the objectives of this research project is to understand if southern yellow pine is comparable to concrete as an internal thermal mass material. Due to concrete’s thermal properties, it is consistently used as a thermal mass material. If the team can prove that wood can also be a consistent thermal mass material when sized correctly the rural south can utilize their natural resources to provide not only structure in builds, but temperature and ventilation control. Therefore, these experiments need to have equal conditions.

The first step in creating a more equal environment was building a shade structure for the low, eastern light. Made of dimensional lumber and an extra blue tarp, the shade screen blocks any direct sunlight from hitting the chimney while allowing air to enter the bottom of the chimney. This will equalize the amount of heat from direct sunlight, also known as radiant heat, the Concrete and Wood Chimney’s experience. However, the radiant heat on the eastern side of the Lab, shown on the left above, experiences may lead to higher ambient air temperature around the Wood Chimney.

To understand if this is having a significant effect on the Wood Chimney in comparison to the Concrete Chimney the team got out the FLIR thermal imaging camera. Thermal imaging is simply the process of converting infrared radiation into visible images that depict the spatial distribution of temperature differences in a scene viewed by a thermal camera. This will help us understand the distribution of heat in the lab. From the thermal imaging photos, we can see the difference in temperature in the Lab. The eastern side, on the upper left, because of the radiant heat from the sunlight stays consistently warmer. The western side, on the lower right, is cooler than the rest of the space because it is mostly shaded from any sunlight. Also, due to the size of the Lab, there is clear heat stratification. As heat rises, it gets stuck under the ceiling. While this environment is not detrimental to the experiments, the team is hoping to be able to move the experiments to the Fabrication Pavilion on Morrisette Campus. There, the experiments will have more consistent shade in a much larger space. The larger space will make a more consistent environment as heat will stratify farther away from the top of the Chimneys.

The team has also begun thinking about their next scale of experiment. They want to test the Optimal Tuning Strategy at human scale. This means the space needs to be large enough for someone to experience the cooling effects as well as see what an internal thermal mass looks like in a space. Scaling up, besides being experiential, will also seek to prove that the Optimal Tuning Strategy is truly proportional and applicable for public buildings. The team has to consider what proportions of space will make the Human Scale Experiment data comparable to the Test Chimney data. This is not so straight forward as they need to make sure the experiments do not become too tall or tight as to impede quick, safe construction as the Human Scale Experiment will be a temporary structure for testing. The Thermal Mass and Buoyancy Ventilation Team is using the Optimal Tuning Application to design the Human Scale Experiment at this schematic phase. The application was recently published by Wolfram Demonstrations Project! The team will soon do a post on understanding and using the app.

Thermal image of Dijon the cat

Last, but not least, here is a thermal image of HomeLab mascot Dijon. No conclusions were made about Dijon based on his environment. Keep Tuning in as the TMVRP team works from HomeLab!