Tightening bolt on Ultra CSV crawl space vent kit installation.

Vents That
Make Sense

Ultra CSV crawl space vent.
The best crawl space vent for replacement or new construction
Easy to install. Improves crawl space ventilation. Provides energy-saving, airtight closure when needed.
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United States of America flag.
Made in USA
Thousands sold and
in service since 2003
Invented, patented, and perfected in the USA by a crawl space maintenance expert.

The need for a better crawl space vent

Ultra CSV Crawl Space Vents work perfectly for both ventilating and encapsulating crawl spaces, in existing homes and new construction.
Proper ventilation or treatment of a crawl space plays a vitally important role in the longevity of a home. Unaddressed moisture and humidity under a home can cause mold, mildew, and dry rot that can weaken and, in some cases, severely damage the structure. Many residential building codes require as much as one square foot of crawl space ventilation per 150 square feet of building footprint. Today, some builders and homeowners prefer to completely encapsulate crawl spaces year-round and equip them with a dehumidifier, requiring vents to be permanently sealed and insulated.
Black wrench icon.
Easy To Install
Ultra CSV Crawl Space Vents install into standard-sized crawl space vent openings in less than 10 minutes with simple tools and are easily adapted to non-typical vent openings and structural interferences. Enjoy complete installation and service from outside the home—crawling under the house is not required.
Black airflow icon.
BETTER VENTILATION
Ultra CSV Crawl Space vents provide over 30% better airflow through the crawl space when open than most slider-style crawl space vents. Unlike many vents that only provide 40 square inches of Net Free Area (NFA), Ultra CSV Crawl Space Vents provide over 52 square inches NFA in the same size foundation vent opening.
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COMPLETE SEAL
WHEN NEEDED
Ultra CSV Crawl Space Vents provide a virtually airtight seal of crawl space vent openings when closed. Closing the Ultra CSV Crawl Space Vent takes less than a minute with the solid seal plate included. For additional energy savings, insulation of your choice may be added inside the vent opening from outside the home.

ULTRA CSV INSTALLS IN LESS THAN 10 MINUTES FROM
OUTSIDE THE HOME

A home owner installing the Ultra CSV vent.An Ultra CSV vent without the insert.
SLIDE THE BAR RIGHT OR LEFT TO VIEW THE EXCLUSIVE CROSS BAR THAT CLAMPS THE ULTRA CSV CRAWL SPACE VENT FRAME SECURELY WITHIN THE FOUNDATION VENT OPENING FROM BEHIND.

SOMETIMES YOU JUST GOT TO VENT

HOW IT ALL STARTED

In April 2023, engineer, inventor, homeowner, and do-it-yourselfer Brad Griffin smelled a rat…

…or at least some critter that had crawled under his house and worn out its welcome. When investigating his crawl space for the source of the smell, he found nothing. What he did find was irreparable damage to his existing slider-style crawl space vents where whatever it was had tried to escape. The vent screens were ripped off the inside and shredded. The vents had to remain closed to keep other pests out until replacement vents could be found.

In times past, Brad had tried replacement crawl space vents from mass retailers with poor results. He found that they didn’t stay in and didn’t seal well in winter. Ones with “automatic” temperature-controlled dampers worked short term until dirt, cobwebs, and corrosion jammed the louvers halfway open. There had to be a better solution.

how ultra csv compares

It’s not rocket science, but it’s the best crawl space vent you can buy

 Plastic slider-style vent
Made in USA
Easy to install
Will positively not fall out when properly installed
Critter-proof screen will not tear or rust
Provides over 52 square inches of Net Free Area
Seals virtually airtight when closed
Completely serviceable from outside the home
May be used for ventilation or encapsulation
Allows for adding insulation in winter, if desired
100% stainless steel installation hardware
Tough, UV-resistant ABS plastic construction
Available in gray color
Paintable to match any home, if desired
A home owner installing the Ultra CSV crawl space vent kit.

Try the vents that make sense

The Ultra CSV Crawl Space vent is proudly made in the USA and guaranteed—period