If your systems is a vapor vacuum system I would think about installing a Hoffmann 76 the reason being that even though they vent slower the upside is they close so vacuum can form which shortens distribution time on start up when in vacuum . Another plus is they will help your system produce steam at lower temps . In my closing thought is that most vapor vacuum systems never see or have to vent much air and when switching to say above big mouth or any standard vent the system will be breathing and sucking in air on the off cycle . So when start up come round you will be waiting for the air to vent out of the mains Andy radiators . I know I’m kinda alone on this but if the boiler is properly sized for the edr and piped properly and clean . I feel it can still be usefully to keep it a vacuum systems as long as it holds a vacuum which indicates a nice and tight system ,if so why let it suck in air and increase potential for corrosion . Of course a vaporstat should be used and if gas and oversized then a 2 stage gas valve would be in order . It s really amazing when you run a vapor vacuum system that still operational and holding vacuum the distribution cannot be beating it’s quick and quite . I know that those 76 are not cheap but I always have one on the truck of course w a big mouth and gortons . Peace and good luck clammy
It looks like you're new here. If you want to get involved, click one of these buttons!