Healthy Indoors | 61
els reasonably low. Where $50,000 or more of sensors in a trailer parked in the driveway was once needed,
technological advances allow us to monitor important home IAQ metrics for a few hundred dollars.
For a few hundred dollars we can get a decent idea of what's going on (no more guessing), and not just tem-
porarily.
Spoiler: it looks like MUCH less than 62.2 ventilation standard is needed for most homes. This is not hard
and fast, but the good news is it allows for us to use a much simpler fresh air system which I'll lay out in detail
in a coming article. Let's look at a specific example.
35 People In One House
In February of 2019 one of our clients, Hallie Bowie, was kind enough to host an "Electrify Everything" event in her
home to show how an all-electric home is totally possible in cold climates. Her electric home looks remarkably like
other homes of its vintage and comes with far better average comfort. Hallie noted to me during a cold snap last
winter that this is the first house where she has no idea what the temperature outdoors is without stepping outside.
(That's thanks to "load matching" and keeping surface temperatures nice and even, as discussed in part 1. I digress.)
Let's look at some data. Most tVOC sensors are cross sensitive to CO2, the one in Foobot is. If you have some
idea of what's going on in a house like cleaning, cooking, or lots of people, you can infer what's being picked up.
In this case I'm pretty sure it's CO2 from a bunch of people breathing since there were 35 people in the house.
Some notes on the house. It has a very simple fresh air system that I turned up to 30 cfm during the event. It got
warm enough inside from all the people that we cracked the sliding door for about an hour, but it was closed by 7 PM.
The chart below is tVOCs aka total volatile organic compounds or chemical pollutants as the event began at 5 PM.
https://photos.app.goo.gl/XPHrYktGqRcX6ZMN7
https://photos.app.goo.gl/7trUmHzm4M8HmGqn6
