Crawl Space Drying Fans – Do they Work & Best Fans to Use

Do Crawl Space Ventilation Fans Work?

First off, putting a ventilation fan in your crawl space will not guarantee fixing any humidity or moisture problems.

In very humid weather or very damp winters using a fan can even allow more external air into the crawl space, which can lead to more moisture or other issues.

The main purpose of a crawl space fan is to bring in external air from the outside into the crawl space. This being that if air is constantly moving inside the crawl space, then you won’t have to worry as much about water accumulating within the crawl space which can create moisture problems.

Nowadays, vent fans are mostly considered to be detrimental to your home as these fans can tend to cause foundation and water issues.

Using these fans may even cause pest concerns under the home, but the fans do have their benefits which we’ll discuss below.

Do I Need Fans In My Crawl Space?

Two main reasons to use a fan within a crawl space are to reduce moisture and improve the air quality.

Setting up a fan in the crawl space can really help dry out moisture and condensation.

They can also help prevent the growth of mold. After using a fan though you will want to setup a dehumidifier as well to keep the area dry.

The only time you want to use a fan in a crawl space is when it’s beneficial to use one.

Since you’re trying to keep the moisture out of the crawl space and you’re bringing in outside air, you’ll want to make sure that the outside air is drier than that of the crawl space.

Again, it comes down to keeping the moisture out and improving the quality of the air within the crawl space.

How many Crawl Space Vent Fans Do I Need?

This will be determined by CFM which means Cubic Feet per Minute. The CFM will help determine what size fan is suited for your crawl space vents.

When purchasing a fan you will want to know how much air the fan can move. The air is measured through the CFM.

To get the correct volume of air in the crawl space you just multiply the height x width x length of crawl space.

Say your crawl space is 40’ long, 20’ wide and 3’ high then the volume of the air would be 2,400 (40x20x3) cubic feet.

Once you have the correct measurements then you can better know how many fans you can use within the allotted space.

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Deploying Crawl Space Fans to Dry Under Your House

Where to place the Fans

Should you not have a dehumidifier, you can place the fan anywhere in the crawl space except for near a door.

You shouldn’t Place the fan near the door because doors can leak air.

So, say the door is on the west end then try placing the fan on the east side so that the fan is drawing air away from the door and across the crawl space.

If you do have a dehumidifier though, aim it at the centre of the crawl space. Then, place the fan as far away as possible from the dehumidifier.

The reason for this is if you place the fan near the dehumidifier, it could capture that dry air and push it outside.

How to use the fans

The fan is designed to take outside air and blow it into the crawl space. This is to make sure air is constantly blowing through the crawl space and that way you won’t have to worry about water accumulating which will also help in avoiding any moisture concerns that could arise.

 What else is Needed Besides Fans…

Another thing to consider when trying to maintain a safe crawl space is making sure all doors and vents are closed properly in very humid/damp weather.

Otherwise, moisture will keep getting into the crawl space. Also, as mentioned earlier, you’ll want to make sure the insulation and ducting is in adequate condition or if it needs replacing.

An energy-efficient dehumidifier is also recommended as well as installing vapor barrier liners. The lining goes on the ground, up the walls, and around any supporting struts in the crawl space.

These are designed to trap water vapor outside the barrier, making sure it stays in the ground and not get into the crawl space.

What to Consider When Choosing a Crawl Space Fan

Before choosing the correct fan, you’ll need to measure the size of the crawl space and determine any tools necessary to install the fan.

You need to choose the best unit to fit the foundation of your home. Inspect the floor of the crawl space and check for any moisture, water droplets, mold or rotting wood.

Also, you’ll need to decide whether to use a free-standing unit or to install the fan.

Installed units should be used only when the structure already has vent holes cut into the foundation.

 These are all determining factors in choosing a proper fan.

Special Fans VS Regular Box Fans in a Crawl Space

A box fan will just bow air throughout the crawl space as it would blow air through your bedroom.

It will do the job, but it’s not the only fan you can use.

A fan such as ATMOX is designed to improve overall conditions in the crawl space while keeping out moisture and water while circulating air throughout.

The choice of the fan depends on what works best for your home and the crawl space itself.

Temperature Controlled Crawl Space Fans with Humidistat – Are they Worth it?

These fans can be very beneficial. When going with this particular fan, make sure you have a vapor barrier across the entire crawl space floor.

You may also need to ensure that the vents on the opposite sides of the crawl space are open. That way, once the fan starts, it can pull air from the crawl space outward.

These types of fans also work better with small crawl spaces as opposed to large ones. Keep that in mind if pursuing this type of fan.

Solar Powered Crawl Space Fans

These are more energy-efficient and a more reliable solution when it comes to placing a fan in your crawl space.

Unlike powered by electricity from the grid, these fans are powered by sun radiation which can give your HVAC a boost without increasing your electric bill.

Overall, a solar powered fan is built to last, it’s quiet, can save you money and is able to perform all year around.

Crawl Space Mechanical Ventilation VS Vapor Barrier

With the mechanical ventilation, you must have a continuously sealed, vapor-retarding ground cover with no fixed ventilation openings to the outdoors and be equipped with an operating exhaust fan.

The vapor barrier is a thick plastic material that is installed across the ground to prevent ground moisture of entering the crawl space entirely.

It’s also best to have a waterproofing system installed too for leaking pipes or water runoff.

Overall, your crawl space will benefit from having a crawl space barrier.

Crawl Space Fan VS Dehumidifier

The main difference between a fan and a dehumidifier is the way they work.

A fan basically circulates air throughout the crawl space, while a dehumidifier works by drawing air into the unit and condenses it over cold coils to remove the water from the air.

The “dried” air is then put back into the crawl space.

There are pros and cons with both units – fan are easy to install and inexpensive. It doesn’t need any upkeep like a dehumidifier does either.

On the other hand, fans can get clogged. A fan doesn’t remove moisture like a dehumidifier does either.

Depending on how damp your crawl space is and the climate in which you live, a fan may not cut it in working on your crawl space.

A dehumidifier has been known to be a great way to remove moisture from a crawl space. You can also control the humidity of the dehumidifier, plus they are very low maintenance.

Some cons to a dehumidifier though are they need to have the water removed from them somehow. They can also be much louder than a fan and they tend to take up more space than a fan.

Compared to a Fan a Dehumidifier will also consume much more electricity.

Just decide which one works best for you and your home.

When to Call a Professional

Keeping a Crawl Space Dry can be very challenging, especially depending on the design of your crawlspace.

You want to catch any issues such as mold formation or water seeping into your home’s structure early on to prevent any further damage

If there is currently large amounts of water in your crawl space that needs to be removed consider calling a Water Damage Restoration company, they have the equipment to remove the water and dry out your crawl space.

As well as Prevent your crawlspace from getting wet in future.

We have Water Damage Restoration Technicians that can help Dry out your Crawl Space And Prevent it from Getting wet in Future.

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