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Do You Need a Vent Fan And Dehumidifier?

On today's blog we will discuss when you will need a vent fan and dehumidifier in the crawl space. How we at Crawl Space Ninja determine the best way to install them. Why both are crucial to crawl space encapsulation.

Crawl Space Ventilation Fan

The Crawl Space Ninja System includes a vent fan and a dehumidifier, but we do get questions if a vent fan is truly needed if you have a dehumidifier. The answer is yes.

The reason for the vent fan is to move soil gases that might be present in your crawl space out. We are located in East Tennessee where there can be radon present. This doesn't mean you have a radon problem but other gases can also be present so we like to take precautions.

Crawl Space Dehumidifier

Remember this is only the case when the dehumidifier is a standalone unit within the crawl space. That means that the dehumidifier will not be pulling in air from the living space above.

The only thing you have to keep in mind is that one vent fan can cover up to 5,000 square feet. Make sure crawl space vents are sealed properly. If you have a larger crawl space, multiple units may be needed.

Other Crawl Space Essentials

A properly installed vapor barrier is also needed. Crawl space insulation cannot be overlooked. Standing water from a flooded crawl space can add humidity as well.

Below is a video that talks a little bit more about this same subject, comment and tell us what you think!

Does Hydrostatic Pressure Affect Humidity

Basement Ninja Waterproofing Services

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  1. Richard LaCaille on August 19, 2019 at 2:18 pm

    I installed a sump pump )3ft away from the access door. I’m also going to install (hang with straps)
    the dehumidifier close to the sump pump to gravity feed the condensation tube. Not sure where to install the vent fan. My first thought was to install it in the center of the access door, which is about 4 ft away from dehumidifier. Is that to close?

    • Michael Church on August 19, 2019 at 3:37 pm

      It may be a good idea to place on the other side of the crawl space so the dry air is pulled further from the dehumidifier. I’m concerned having the AVS too close would suck all your dry air out before having a chance to travel throughout the crawl space. Great question, thank you.

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