Rant: Tired of seeing wireless sensors mounted right next to metal ductwork

I was on a service call Tuesday at a house in Arlington and found three door sensors all showing intermittent faults. Pulled the covers and every single one was within 4 inches of the HVAC return. I mean come on guys, that cheap metal mesh kills the signal. I had to move all three and re-pair them. Cost the homeowner an extra hour of labor. Do y'all not test range before you stick these things on?

3 comments

3 Comments

singh.jessica1mo agoTop Commenter

Three of my last six service calls had sensors within six inches of metal ductwork. That aluminum tape and thin sheet metal acts like a shield (it’s basically a Faraday cage for the 433MHz signal). Just a couple inches of distance can make the difference between a solid link and constant dropouts.

wood.zara1mo ago

Forgot to check if the sensor's antenna orientation plays into this too. Sometimes rotating it 90 degrees clears up the interference even if you can't move it.

milap354d ago

Yeah, turning the antenna 90 degrees has saved my bacon more than once. Did a job on a rooftop last month with a sensor mounted near a big metal HVAC unit. Rotated the antenna just a hair and the signal went from nothing to solid. Also helps to point the antenna away from any long metal runs like conduit or piping. Those can act like big antennas themselves and just suck the signal right up.