To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
I've used a lot of solid state relays, but never for heating/cooling equipment. Some quirks that might cause problems:
1) Heat is their enemy and the larger the load, the more heat they produce--you need a good heat sink and good natural ventilation (forced ventilation if you pack a lot of them in a small area).
2) Pay careful attention to the load rating. Resistive loads aren't as bad as inductive loads but even with resistive loads give yourself at least 25% headroom in the load rating. A filament burning out in a lightbulb will frequently take out a closely sized solid state relay.
3) They're extremely reliable--I had one set of four that probably each switched 40-50 times per hour for 4-5 hours per day for over 10 years. When they fry due to excessive load they fail open. I did however have one fail closed for a reason I never understood--this alone may be a "killer".
4) You can only test them with a load connected. You can't just use an ohm meter.
5) They're available in a number of "coil" voltages--I've only used low voltage DC but believe I've seen them for 110VAC.