Temp-Vent Series 6 Automatic Foundation Vent

Used these under a deck so I wouldn't to manually close them during the winter. Worked well. Installed as per instructions with no problems. Only negative is the alignment clips did not anchor well in the vent housing. Had to pry out the small tension prongs a little to make the clips fit in the housing tightly.

I tested this unit before I installed it. It worked great. As the temperature warmed up or cooled off the damper moved smoothly, freely quietly. It actually worked better then I expected. As it gets colder it closes, closing completely at 40 degrees and opening fully at 70 degrees. However, it only works in one position. Not side ways not upside down. Just so you know.

This is the best foundation vent design I have found, and I have been looking for some time. Coincidentally, these are an improved design of a similar model that am am replacing that were improperly installed, and suffered other damaged over 10 years prior. In particular, the design change puts the thermostatic coil is inside the box, on the center vane. And most importantly for me, is these foundation vents ship with both spring clips and set screws. They do require some pre-assembly before installation which is my only negative, but once installed these are great. I used a 4" c-clamp to press the nuts into the plastic housing for the set screws, and needed to slightly bend out the locking tab on the clips with some needle-nose pliers. I expect these will last for years.