Review on 🔄 Tjernlund PS1503 Airstat Pressure Switch for Improved SEO by Justin Peck

5 stars - Tjernlund's technical support is excellent. Not being an electrician, I have to rewire every time I do something. 2 previous reviews provided information on how they did the wiring. It didn't sound right to me. Essentially such a switch should open the hot side (black). Just like a wall switch. this. hot (black) from the fan to a normally open switch and a common switch to turn on (socket hot black) when you plug in an outlet. It will work the other way as well, but breaking the neutral side is not safe as far as I know. Tjernland's engineer, Sean, helped with advice/confirmations. Excellent support. I hope for a good result. To catch up - this transition didn't work for me. First I connected a lightbulb to it to simulate a fan once I had finished the whole installation. I watched the switch turn the lightbulb on and off when the air handler started and it worked flawlessly for days. However, when I installed a fan (Tjernlund M-10) it started intermittently. The blower starts and the fan cycles on and off quickly before running continuously. When the main fan stopped, it also cycled on and off quickly before finally turning off. This may be because I have a variable speed fan in the myTrane system. My next step is to install a relay, which I understand can be powered from an electronic air cleaner circuit (I didn't install an EAC, but the system has connectors for it). Now I'm going to get my HVAC friend to do this as it feels more like a job than I enjoy doing it myself. I believe it will work from what he told me. I will say to use a quality fan. M-10 Tjernlund produces a really powerful airflow (about 2 times more than cheap ducted fans like Suncourt). Also, an M-10 style fan is better if you can overcome the resistance. In my case I placed it at 30' 10" diameter just in front of the 2nd junction box in the attic that feeds 3 runs (8" in diameter and about 13' long) into the upstairs room. Thanks to the M-10, the upper floors were 11-12 degrees higher than the lower ones, 1 degree lower. So it did a really good job of cooling the room. There was also very little balance impact on the two main runs below (roughly 2000 square feet). Please note that I used the Tjernlund SCP speed switch and as mentioned as you decrease the speed the fan motor noise increases. Being on the other side of the wall is not a problem for me. With all linear ducts, fans can be a great option to solve your problems, but system variables can make it difficult to achieve a successful outcome. I'm optimistic this will work, and for me it's a lot cheaper/better than installing a separate upstairs unit (330 sqft bonus room/studio). Hope this information helps others. —— Last Update - My Trane unit had so-called "dry contacts" for the electronic air purifier, which are simple clamps that power the connection to the unit. So no extra relays are needed, just connect a fan to it. Works perfect!