By Molly Cox
The Residential Green Building Committee gathered on October 16th, 2017. We had a guest presentation from John Rockwell, of Zehnder America. He was here to help us understand proper and efficient mechanical ventilation standards for buildings.
He started off by emphasizing the importance of making buildings airtight, and not just jumping straight to insulation measures when looking for fixes. He continued to explain that air movement is the primary goal, because of all the contaminants and toxins buildings can have inside (in the rugs, furniture, etc), and we need that to move through.
John went on to explore the different ventilation options: Exhaust Ventilation, Supply Ventilation, Balanced Ventilation and Heat Recovery Ventilation. The conclusion was that the Balanced Ventilation is highly recommended in conjunction with an HRV or ERV, over Supply Ventilation for example, which pulls outside air into the home, while the stale air exits the home through building envelope leakage. The HRV serves as a heat exchanger between the fresh and stale air, and they actually have a higher heat recovery efficiency than an ERV. The reason being is because the HRV isn’t focused on moisture transfer like the ERV’s are, so there are more resources being dedicated to the heat exchange.
John explained that when choosing to implement an HRV or ERV, it is important to think about climate, occupancy, and humidity levels. Not only are all these ventilation methods supposed to be efficient for overall energy use, but they are also supposed to enhance the health and comfort of the inhabitants within the building.
John taught us a lot on Monday night, and was an extraordinary teacher for all of us! We hope you will join us at our next Residential Green Building Committee meeting to continue the conversation and learn from one another.
Here are some upcoming events to keep an eye on:
October Greenbuild Mixer with BCBS of Massachusetts Oct 26th, Boston
How to Network at Greenbuild and Build Your Career in Sustainability Oct 26th, Boston