UnderAire Crawl Space Exhaust Fan w/ Dehumidistat, 220 cfm


Brand: Tjernlund

Mfr Part#: V2D

Availability: In Stock
Usually ships: Today, if ordered by 3pm
Qty Price
$116.95 / each & Free Shipping
  • Description
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  • Reviews (2)
  • FAQs

Tjernlund V2D UnderAire Fan Powered Crawl Space Exhaust Ventilator quickly reduces moisture helping to protect both home and occupants.


Ventilates excess moisture, the cause of mold, mildew and wood rot. Increases air circulation to fight condensation.

Constant operation helps vent radon, treated wood offgassing and odors that might otherwise migrate into living areas.


The Tjernlund V2D features two fans and large faceplate sized for ventilation openings through block foundations.


Choosing between V1D and V2D it is needed first to determine the number of UnderAire Ventilators:

Calculate the cubic area of the crawl space by multiplying the length x width x height. Divide this number by 15 to determine the minimum CFM necessary to fully ventilate the space in 15 minutes.


Example: 20' wide x 40' long x 3' high crawl space = 2,400 cubic ft. 2400 cubic ft. ? 15 minutes = 160 CFM of ventilation. Choose two V1D ventilators or one V2D ventilator.




Facts to know about Crawl Space Ventilation:


From Mississippi State University Extension Service:

If soil is damp, as much as 20 gallons of water per 24 hours can evaporate into the air in a 1,400 sq. ft crawl space.


Primary causes of excess moisture include:

- Surface runoff water;

- Poor ventilation;

- No or poor ground vapor barrier;


Signs of excess moisture in crawl space:

- Soil is wet;

- Surface organism growth on floor joists;

- Wet insulation;

- Musty odors in crawl space or living areas;

- Excessive moisture in living areas tending to migrate towards windows;


  • Includes adjustable dehumidistat;
  • Thermostat deactivates fan below 40F to avoid freeze-ups;
  • Galvanized face plate may be trimmed if necessary;
  • Has 6' grounded power cord;

Technical Specifications:

  • Number of Fans: 2;
  • Performance: 220 CFM;
  • Motor: 2 @ 115/1/60, 0.60 amp;
  • Dehumidistat: OFF/ON or 20-80% RH;
  • Thermostat: Opens at 40F;
  • Dimensions: 18" x 9" x 2";
UnderAire Crawl Space Exhaust Fan w/ Dehumidistat, 220 cfm has an average 5.0 out of 5 rating based on 2 user reviews.
Air & Moisture Circulation
By Bob (from Santa Cruz Ca) on 12/1/2015
Air circulation is the key to keeping moisture prone areas from developing or creating mold, mildew and helping detour dry rot. The Tjernlund V2D with its humidity control is the added benefit. I’ve placed the V2Ds on a timer that reduces noise during sleeping hours and higher temperature periods. I’ve provided additional insulation near the V2D to keep noise to a minimum.
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Tjernlund V2D UnderAire ventilation fans
By jay l. (from Franklin, TN) on 11/10/2013
This Tjernlund product seems extremely well built and should prove very useful. Fans are super-quiet and the UnderAire unit has a dehumidistat control as well as a temperature shutdown for cold weather. I'm very pleased with the product and especially pleased with the service provided by pexuniverse.com
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