“The glory of the entropic potential of water!!”
Title Statement by: Jacob Deva Racusin, Monday April 6th, 2015
For most, Easter Long weekend was an opportunity to get out of town or spend time with family. This year, for the members of Greening Homes, it was an opportunity to spend some time in the classroom delving deeper into the realms of building science. Organized by the Endeavour Centre of Peterborough and led by Jacob Deva Racusin of New Frameworks Natural Building in Vermont, 16 GH employees and a few special guests, spent four days at GH’s new office space, talking about science, physics and building.
As builders we often get focused on the tangible things – the stuff we can see and touch. However, underlying everything we do is the constant ‘battle with water’ in all its forms.
Friday started with an intro to building science components – heat, moisture, structure, acoustics and fire. We jumped straight into thermodynamics and hygrothermodynamics, looking at forms of heat and moisture and how it moves. Basically, the laws are simple. Everything moves from high to low – high concentration to low concentration, high pressure to low pressure, high temperature to low temperature.
While talking about convection, conduction and radiation, Jacob broke out some experiment tools and we watched as hot red coloured water and cold blue coloured water in a clear baking pan merged into a convective loop – the very same loop that happens with air in a house when we feel the ‘heat rise’ and cool air ‘drop’.
Saturday and Sunday brought our focus toward the building envelope and all of its boundaries. Controlling rain, air, thermal (losses and gains) and vapour are the key components. Managing rain (bulk water) water and designing good rain screens are at the top of the priority list in keeping the inside dry. Next on the list: the importance of a good air seal and the differences between that and a vapour retarder. And then of course, as with all cold climate building, there was much discussion about insulation – how much 0f what to put where. It’s not as simple as one wold have thought!
We were able to take the building envelope discussion on a fielded trip to a nearby residence where a blower door was set up to demonstrate air flow and thermal boundaries. With the house depressurized to a standard 50 Pa, a thermal camera (and the naked hand) could easily see (and feel) the entry points of cold and air. A very good reminder that things which may look solid, may not in fact, be solid.
As Monday rolled around, the discussions fell to mechanical systems. As we build better, more insulated, more efficient houses, our energy requirements go down. There are many ways to achieve heating and cooling and much of it is site specific. So much depends on fuel types, water systems, upfront costs vs long term costs, budget and the site itself.
By the end of the day, it is safe to say, the room was tired, overloaded with information, but inspired and excited to keep the conversations going. As a group, we brought many backgrounds to the table from conventional building to straw bale and everything in between. The knowledge sharing and construction detail discussions were many and varied.
Jacob’s enthusiasm for physics, building and building science was infectious and his knowledge base is vast. He encouraged us all to look beyond the battle with water and see it as something amazing. Understanding how it works and how it moves empowers the builder to build better buildings.
As a construction manager with GH, it is an amazing thing to have an entire crew who has a working knowledge of the science behind building. Understanding how and why we are doing things and having the knowledge to question or suggest different ways of detailing will only ever make us better as a whole.
A week and a half after the crash course, we all reassembled at the office to debrief and discuss how we intend to move forward with all of the ideas and discussions that were raised. An hour meeting turned into 3 hrs of animated and heated debates and discussions over the pros and cons of different types of insulation, window installation details, and construction materials. It is clear this is the beginning of a new building era with high energy costs and fossil fuels on the depletion. What an exciting time to be part of a company thirsting for knowledge and information and striving to be part of the solution!
* This blog was written by GH Construction Manager, Janette Meyrick