Leading up to living in the Centennial Park Active House, I thought a lot about what we could do to demonstrate this amazing house as well as what elements I was looking forward to exploring. I kind of took indoor air quality for granted. I have read, heard and even spoken about the benefits of fresh air, fresh air being synonymous with good air quality. It wasn’t until I was able to measure the quality of the air in the house and correlate this with how I felt that I realized how much I was personally affected by indoor air quality. I now appreciate how poor air quality makes me unfocused and even drowsy. I also noticed that I wake more frequently when the air quality is poor; sometimes resulting in me just getting up early, even though I should get more sleep. Living in Active House Centennial Park has made me aware of the importance of fresh air and its effects on me.

Most of what makes Active House Centennial Park perform so well was designed-in, built-in or is automated. This is great for those who don’t want to be tinkering and monitoring etc, which is most people. But I’m an engineer and part of my involvement in the project is tinkering and monitoring. In the case of indoor air quality, I was able to have a lot of influence. I found this fun. It became a challenge, no a quest really, to optimize the indoor air quality of the house over the summer. I had some key tools on my quest. I had a monitoring system measuring indoor air quality, temperature and humidity as well as the weather forecast for outdoor conditions – both available remotely on my phone. With these tools in-hand I was well equipped to take on poor indoor air quality in a battle to the end! And when I wasn’t home to fight the good fight, I could text Bethany help out, sometimes to her annoyance.

patio door

“Opening up” the house for fresh air – a family effort!

Statistics show we typically spend 90% of our time indoors and that indoor air quality is 2-5 times worse than outside. This is why bringing outdoor air into a house is such a good thing to do. So why not leave the windows open all the time? Well, along with the freshness of outdoor air, sometimes the outdoor humidity and temperature can reduce the comfort of the indoor space (too hot, too cold or too sticky). So I had to decide when to open the windows and when not to. My father-in-law and I had a brief bonding moment over this as he installed a weather station at his house. Unknowingly, we were both in search of an easy way to decide if we could leave the windows open overnight to benefit from night cooling. In my case, I had determined that if the outside temperature dipped below 25C or the “feels like” temperature, which factors in humidity, dipped below 27C, we could open the windows and maintain comfort. Much above these temperatures meant we were sticking to our PJs in the morning, not comfortable. And yes, it happened more than once as we narrowed in on acceptable thresholds – all part of the quest, right Bethany?

Netatmo open window

The monitoring showed that the air quality became poor after running the AC for a day or more without any ventilation.

The house has an ERV, energy recovery ventilation, for mechanical ventilation. Apparently, one does not run these things in the summer as I made the house too humid, again with the sticky PJs in the morning. I wanted to run it on the hot and humid nights that we had the air conditioner running and couldn’t open the windows. The monitoring showed that the air quality became poor after running the AC for a day or more without any ventilation. In the end, it was easier to manage the air quality and humidity by opening the windows for 10-15 minutes on the hot and humid days for a good old European “airing”. I remember my great-grandma doing this when I was a kid and Bethany’s family still does this in the UK. Now that the evenings are too cool to open all the windows, the ERV does a fine job of keeping the air quality at an acceptable level. We still tend to do an “airing” in some situations, like hosting people. The mechanical ventilation is sized to cover basic occupancy. Since the house design is optimized for a natural ventilation, one can do an airing in a short period of time, reducing the risk of overshooting on humidity or temperature by forgetting to close the windows or turn off the ERV.

My summer quest has ended and I feel I have gained a deeper understanding of the importance of indoor air quality and how to manage it, not to mention how to avoid my family waking up in sticky PJs. A final note, if you’re one of those tinkering types, Bethany will attest that not everyone appreciates hourly updates, especially when they include graphs, so be mindful of those who do not share your quest!