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Joined 1 year ago
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Cake day: December 4th, 2024

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  • It you’re using a relay to turn it on and off then just put like a 90F furnace high limit switch on the air inlet side of the heater and run the control signal for the relay through that high limit switch. That way if the air going into the space heater gets too hot from the room getting too hot or the area around the heater gets too hot from the fan failing, it’ll shut off. Also furnace safeties are cheap, easy to find, and already designed to fail open circuit for safety.


  • Normally phosgene isn’t quite that deadly. If you catch it full concentration then you’re in for a bad time as your lungs start blistering but that definitely isn’t something that happens from a small leak unless its also in a confined space. I’ve gotten a face full of phosgene a few times on the job and you definitely notice it. Idk what it smells like because to me it just smells like pain. It feels like you just took a huff off a bottle of drain cleaner. If you get hit with enough of it, it’ll leave you short of breath and your chest burning but the only time I ever got hit with that much was the time I took a plasma cutter to an old refrigerant can I had forgotten to purge with nitrogen first while working in a closed garrage.

    Suffice it to say, you would definitely know it if you got exposed to any significant amount of phosgene.






  • HVAC-R tech here.

    Not sure what you mean about simulating high temps on the thermostat. If you want to trick the thermostat into seeing a higher temp than it is actually at then you would need to find the temp sensor on the thermostat (usually a thermistor) and replace it with something where you can manually control the input like a potentiometer if there was a thermistor there.

    If you’re talking about simulating calls from your thermostat to your hvac system, then you can usually do that with just some jumper wires if your hvac system has a built in transformer (almost all new systems do). You just remove the thermostat and jumper the hot wire (R or Rc) to whatever call you want to make.

    Edit: I should probably note that if you accidentally jumper anything to ground or to common then you will likely trip the breaker or blow the fuse on your systems transformer. If you do that then you’ll need to find that transformer (usually in the airhandler, assuming a standard residential split system) and reset the breaker or replace that fuse before your system will work again.