Omnisense 1

October 3, 2012

The first Omnisense sensor goes in!

We are seriously curious about how this construction technique performs. So, we bought a monitoring system that will tell us the temperature, relative humidity, and wood moisture content at 10 spots throughout the house. Wireless sensors will talk to the central hub, which sends data to the mothership, which logs the data and creates fun graphs for us on demand. We're sure to go on and on about this later, but for now we just wanted to show you the first sensor going into the wall.

Before they finish the siding, we wanted to get a sensor in the furring near a window. Window details are the achilles heal of this exterior-insulation system... and most buildings in general. The biggest question for our particular design is whether our trim will keep enough water out from behind the siding so the furring strips won't rot. We are assuming some water will get back there from lots of different junctions, but that's why the furring strips are there in the first place: to let the air flow through the wall and dry out everything outside of the weather barrier. (Ideally very very little ever gets past that weather barrier.)

We had to cut a hole in the board foam to fit the sensor behind the furring, so we filled that area with spray foam to block any leaks we had created and add back as much insulation as possible. We also covered the whole area with flexible flashing (an extremely sticky rubber sheet) to leave a clean path for any water to keep right on going past the hole. The sensor is screwed through this layer into the furring.

Unfortunately this means we won't get much of a relative humidity reading because the sensor is pretty much sealed in there now, but this spot is really looking for moisture information. Plus it'll be interesting to be able to compare the temperature at the outermost layer of insulation to the temperature deeper inside the house.