In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Is there any theory behind what type of vent to put on a 1-pipe TRV? I'm thinking large vents .. warm the room .. shed the load .. but I'm happy to hear other people's thoughts .. especially those that have had them installed a while. I just added 6 OPS TRV in my bedrooms, kitchen and mudroom (mudroom has an exposed pipe that helps to heat it).