I have temperature/humidity sensors in the back yard, both for Home Assistant and a La Crosse “atomic clock” on the wall of my office. These had been mounted nicely in the shade on a north-facing post on our old wooden fence, but after the fence was replaced I needed to find somewhere else to put them. The first place I tried, the back side of a utility pole, was too close to the fence and they’d read overly-warm in the evenings as the sun was hitting it. (And had the legal issues around mounting things on a utility pole.)
There are myriad different “solar radiation shields” available either for purchase or 3D printing, but they are generally designed to hold one sensor and be mounted on a pole, get held together with bolts, or just aren’t a great design.
I needed to hold two (or more) sensors and being a bit bored (because we’re in the crappy onset of winter here), I designed this, which is available here on Printables: Solar Radiation Shield for Outdoor Temperature Sensors (Variable Height w/ Chain Link Fence Mount
(Or you can download the files here: radiation_shield_for_outdoor_sensors_v1.zip)
I’m really happy with how it came out. In the end it’s a simple two-piece (plus mount) design, with one being the roof and the other a body piece. Each body piece is 15mm tall so I printed off the requisite number to hold my sensors (nine), one roof, and stuck it all together with J-B Weld PlasticBonder epoxy. Pegs and holes align the pieces and make it easy to glue together.
The vents offer shade all the way to horizontal while still having massive openings, so I think it’ll work well. The roof is a bit more translucent than I cared for, but by lining it with some foil tape it’s now nicely opaque. I’m not concerned about the transparency of the vent slots, but may add tape later or re-print with a different filament if it seems to be a problem.
Currently I have La Crosse TX141-BV4 and ZOOZ ZSE44 sensors installed, but may add others as I want to replace the ZSE44 with something that reads negative values. The sensors are held in place using 3M VHB 4910, which is easy to remove (by sawing through with dental floss then rolling off with a finger) but otherwise holds very firmly, especially against shear loads. It’s also thick enough to fit between the ribs on the back of the ZSE44 mount. And I had it on hand.
I initially designed this to use QUEEN SIZE BrickClip fasteners and hang it off the north-facing side of the chimney. Due to the weight of the assembled unit with sensors (~350g) and wanting to keep it away from the house’s thermal mass, I designed a chain link fence post mount. This allowed me to place it quite close to where the sensors previously had been, a nicely shaded yet breezy location. The designed-in slot (originally for BrickClips) just happened to allow easy addition of other mounts.
The entire unit was attached to a chain link fence post using black UV-resistant cable ties and with 3M VHB 5925 tape for a bit of additional stability. This tape works well but also was chosen because I had it on hand and it’s nice and thin. While this is a strong adhesive it’s really only needed for a bit of friction to keep the mount from twisting on the pole if bumped.
So how does this one differ from the other designs I came across? Or, differently stated, why did I bother making my own?
- Sensor-Agnostic: Flat platform allows any sensor to be stuck in place. Most designs are for a single sensor type.
- Larger: Most other designs only hold one sensor. I wanted to hold two or three.
- No hardware: Many other designs are held together with bolts. I’m fine with gluing it together as this makes everything else simpler.
- Flexible Mounting: A simple 15mm x 5mm notch in the back both allows BrickClip fasteners to be used while also a simple platform for integrating other mounts (such as the chain link fence mount).
- Full Body Support / No Arm: Many other mounts replicate the shield-on-an-arm design of commercial pole mounts. I am concerned about FDM printed thermoplastic sagging, so either this needed to be metal, or the support done differently. I also had no need for a pole mount.