I would like to install these on a vaulted porch ceiling. Will they still function on a horizontal surface?
The mechanism used in TEMP VENTS will work fine in most any position so you should be able to use them horizontally with no issue. If you find they aren’t capable of releasing the air fast enough, consider the use of a POWER VENT shown in our MOLD CONTROL ARTICLE. There are several options like HUMIDITY THERMOSTATS that can help keep them working when you want them to open and close.