very loud if you plan to place them under a bedroom. loud 'hum' noise.
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Tjernlund UnderAire Crawl Space Ventilator, Deluxe Two Crawl Space Fan, 220 CFM, Model# V2D

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Shipping:
Available nowStore Pickup:
- Deluxe two-fan ventilator
- Built-in dehumidistat
- Freeze protection thermostat
- Sealed bearing motors for long life
- Mounts into ventilation openings in block foundations
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Description
Key Specs
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Product Summary
What's Included
- (1) Tjernlund UnderAire Crawl Space Ventilator -- Deluxe Two Crawl Space Fan, Model# V2D
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Banish Damp Crawl Spaces
Ventilation is the Answer
The Tjernlund UnderAire™ fan-powered ventilator protects your home and family by quickly reducing moisture in crawl spaces. This increased air circulation prevents mold, mildew, condensation and wood rot. It also helps vent radon gas, treated wood gases and odors, preventing them from entering your living spaces and threatening your family's health.
Built Tough
This Tjernland deluxe two-fan crawl space ventilator is sturdily built from heavy-gauge galvanized steel and is equipped with sealed bearing fan motors rated for continuous duty. This is the only crawl space ventilator with a special ETL Safety listing “suitable for damp locations.”
Simple to Install and Use
The two-fan ventilator features a trimmable galvanized steel faceplate, so it's easy to fit into any space. It typically mounts into ventilation openings in block foundations. Ventilator can be installed in minutes with the pre-installed power cord and included hardware packet. Fan is equipped with built-in automatic humidity control and freeze control thermostat. The controls are easy to use and understand. The UnderAire ventilator will instantly go to work, drawing out moisture from your crawl space.
How Many Ventilators Will I Need?
Calculate the cubic area of the crawl space by multiplying the length x width x height (in feet). Divide this number by 15 to determine the minimum CFM required to fully ventilate the space in 15 minutes. For example, this two-fan crawl space ventilator delivers 220 CFM and will ventilate a 3,600 cubic foot area in 15 minutes.
Shop with confidence
Warranty Protection
This heavy-duty Tjernlund crawl space ventilator is built to last. But to give you extra peace of mind, you are protected with a one-year limited warranty on this product.
Expert Answers are Available
Northern Tool + Equipment is here to help you succeed. Our field-trainied, dedicated team of experts is ready to help — call or email and you'll get a prompt response.
Guaranteed Satisfaction
Shop in complete confidence, knowing that Northern Tool + Equipment protects your investment and is ready to provide you with the assistance and helpful resources you need.
Features + Benefits

- Deluxe two-fan ventilator
- Built-in dehumidistat
- Freeze protection thermostat
- Sealed bearing motors for long life
- Mounts into ventilation openings in block foundations
- Galvanized faceplate can be trimmed to fit
Key Specs
| Attribute | Specification |
|---|---|
item# | 250746 |
Brand | Tjernlund |
Manufacturer's Warranty | 12 months parts/12months labor |
Ship Weight | 6.4 LB |
| Attribute | Specification |
|---|---|
Air Delivery | 220 cfm |
Outdoor Rated | No |
Volts | 110 |
Speeds (qty.) | 1 |
Reviews
Questions & Answers
Questions
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· 13 years ago
How loud is this fan? My ideal install area is directly under two different bedrooms and I want to make sure that this will not keep everyone awake.
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vents· 9 years ago
Helpful?
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rachael1· 10 years ago
I installed it in my craw space under my house and I can hear it in my dining room but it is right outside the room how ever It doesn't bother me and is working great
Helpful?
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Orly· 12 years ago
You will hear the fan running but it will not disturb your sleep. I have mine installed beneath my bedroom but it has never interfered with my sleep.
Helpful?
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ProductExpert25· 13 years ago
The Crawl Space Ventilator is not sound level rated but are "very quiet".
Helpful?
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· 13 years ago
My foundation is concrete not block, It has openings in it,2'x2' so can I mount it in one of these openings?
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Skydancer· 10 years ago
Yes. You would just have to frame in an insert to fit the fan.
Helpful?
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rachael1· 10 years ago
yes the fan is 18/9/2 how ever if you anchor some braces like boards to reduce the hole you can mount the fan
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ProductExpert41· 13 years ago
This item could be mounted in one of those 2' x 2' openings.
Helpful?
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· 14 years ago
does this unit include a backdraft damper
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Skydancer· 10 years ago
No.
Helpful?
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BW550· 11 years ago
No, it does not
Helpful?
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ProductExpert25· 14 years ago
The ventilator does not come with a back draft damper. The unit has a temperature cut off @ 40 degrees and is meant to be used primarily in spring, summer and fall when weather is dampest.
Helpful?
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· 7 years ago
Can this be used for a Chicken Coop to remove ammonia odor and cool the coop?
If not what would be best for a chicken coop?
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Handy311· 7 years ago
Yes, as long as you have safe power, and a vent to let fresh air in.
Helpful?
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ProductExpert11· 7 years ago
This ventilator can be used in a chicken coop application to remove the ammonia odor and cool the coop. Both of the ventilator's fans exhaust in the same direction.
Helpful?
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· 7 years ago
Can this be covered in winter to prevent air infiltration?
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Handy311· 7 years ago
Yes, but also turn it to off, and/or unplug it.
Helpful?
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ProductExpert30· 7 years ago
This can be covered during winter months to prevent cold aid infiltration. You would unplug the ventilator while it is covered and not in use. A cover kit would not be available from Northern Tool or the manufacturer.
Helpful?
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· 7 years ago
I have 4 vents. 1 at each corner of the house. If installing 2 V2D units, do I install both on the same side of the house or at opposite ends?
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Handy311· 7 years ago
All things being equal (no walls or large obstructions) I would put them both on the same side, then they are not fighting with each other, but working together.
Helpful?
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ProductExpert30· 7 years ago
The Ventilators would be installed at the same side of the house for flow through ventilation.
Helpful?
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· 7 years ago
Does it draw air in or out of the crawl space?
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1TexNDallas· 7 years ago
The V2D draws air out of the crawl space when mounted with the control knob facing the crawl space.
Helpful?
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ProductExpert29· 7 years ago
This unit is designed to draw air out of a crawl space.
Helpful?
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· 7 years ago
which way do the fans blow
can you reverse the direction of the fan blows
if your looking at the controls is it blowing air in or sucking air out?
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Ru4titanium· 7 years ago
No. blows out only, I put one on opposite sides of crawl space. One on side and one on back. Works great
Helpful?
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ProductExpert40· 7 years ago
This fan is a crawl space ventilator fan. It draws air from inside and exhausts the air to the outdoors. The control and corded side should be inside and exhausts the air out. You cannot reverse the direction the air blows out on this fan.
Helpful?
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· 8 years ago
How long is the power cord?
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TheFloodMedix· 8 years ago
About 6'
Helpful?
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ProductExpert40· 8 years ago
The power cord for this crawl space ventilator is 6 foot long.
Helpful?
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· 9 years ago
Where does it measure the temperature - outside air temp or from the crawlspace air?
Where does it measure the temperature - outside air temp or from the crawlspace air?
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dude54· 9 years ago
inside
Helpful?
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ProductExpert10· 9 years ago
This item will measure the temperature of the crawl space air.
Helpful?
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Warranty
Manufacturer's Warranty
12 months parts/12months labor
Extend Your Warranty Coverage with a Northern Protection Plan (NPP)
Replacement Plan — 1 Year
A Northern Protection Plan is available after adding the product to your shopping cart.
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Specifications
220 cfm
160 cfm
220 cfm
110 cfm
No
No
No
No
110
120
120
120
1
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1
1
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50
40
20
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