M2D

I'm actually using this fan ventilator for my garage, not a crawl space and so far, it's working great. It was quite easy to install and came with all the hardware needed, including four thin foam strips with sticky tape on one side that made the installation more professional and allowed for a nice, tight fit. Following the instructions, it was quite easy to connect the device to my home Wi-Fi and the app set up was quick and easy. Once the device is added to the app, you can turn it on/off and change the percentage of humidity at which you want the fan to automatically turn on. The CFM's are great for my purpose. Since we live in the desert, our garage gets quite hot when parking two cars in it (engine heat and ambient temperature). This fan has helped pull the hot air out, blowing it outside of our house, bringing fresh air into the garage as long as I have the fan turned on and it's working great. The installation took all of 10 minutes and the app set up took another five minutes. Quick and easy!

When we were about to sell our house, the buyer insisted on having a Radon test performed. We have never had any testing, nor an inkling that Radon was even present in our location, as no-one around here tests for Radon. When the readings, over a 4-day period, revealed radon in the 3 range, we were amazed, although not alarmed, as under 4 is not even guaranteed by the removal companies. Being proactive, we bought from Amazon, a Hound 3699 Radon detector and placed it in numerous rooms of the house. All rooms tested under 4, but the crawl space readings meandered between 3 & 6. I read the reviews regarding this fan and decided to give it a try, exhausting crawlspace air with all other vents closed, WOW! After only one day, readings in the crawlspace now are consistently under 2. Upon first plugging in, the unit produced a sound just like a drone taking off. I was concerned that the sound would/could be annoying, but once installed, in the crawlspace, under the insulated floor, the fan cannot be heard. If you are within 2-3 feet of the outside vent, the sound produced is akin to a clothes dryer. I am extremely pleased with this purchase! UPDATE: upon moving the radon measuring unit from the crawlspace to the living area, the Radon reading is coming in around .78 *WOW*!! This fan does its job!! One week update: Readings now sub-1, measuring between .20 and .673 November 2025 update: The living area of the house now reads under .50pCiL 24/7 I let the fan run continuously with a temperature reading of 60/61 with relative humidity averaging 45% I have radiant floor heating (boiler operated) and I detect no additional increase in energy usage and no effect on the tile floors. The crawlspace floor is covered with visqueen and the floor is insulated with fiberglass batting. Winters can be brutal here, so I will update if I run into any issues. So far, is it in the 30's.

Sacramento isn't especially humid most parts of the year, but during the winter it can get into the 80-90% range. In our 1950s house with uninsulated walls and floors and heating kept around 68 F, this means indoor humidity can approach the ~75% range, enough that clothes in the closet can start to develop a musty smell and condensation begins to occur on the windows overnight. A dehumidifier is one way to deal with this, but uses a lot of electricity. Just as bothersome, poor crawlspace ventilation results in stagnant, moist air and quickly produces a musty smell which can permeate the house and makes a comfortable environment for spiders and insects. Crawlspace encapsulation is expensive and/or labor intensive, from what I can tell, pretty rare around here. Thus, we looked to this crawlspace fan to resolve some of the stagnant air issues in the crawlspace, which would also hopefully reduce some of the indoor humidity issues in the process more economically than relying purely on a dehumidifier. Install wasn't fun in our 2' crawlspace, but built character (or something). I had to make a plywood frame to get this flush with the crawlspace vent, and also cut out some of the metal sheeting. After initial installation below our master bedroom, we were getting noticeable noise coming through the (uninsulated hardwood) floor. This wasn't really noticeable from the crawlspace, because the noise of rushing air was masking it, but we were getting a tone of ~800 Hz peaks at 35 dBA or so, enough to be annoying without a fan to provide white noise. The next day I went back in, taking some advice from the reviews here to add D-style weather stripping around the perimeter of the metal sheet, and also added rubber washers to all the screws. I also added a timer outlet with a remote so I wouldn't have to crawl back in if we had a power outage or something else that threw off the timing. The weather stripping/rubber washers reduced the sound in the bedroom to 300 Hz peaks at around 30 dBA... a much less annoying tone and perceived at about half as loud, easy to mask with a fan running on low. So, I would recommend that modification if you are noise-sensitive. The fan itself moves a good amount of air and appears to be of very solid construction. I have no doubt about its durability. As to the effectiveness of the additional crawlspace ventilation in resolving our issues, time will tell. I have a humidity datalogger in both the house and the crawlspace, so over time I hope to get some good data about its effectiveness.

We got it for radon remediation. Overall it works well and pulls out a lot more air than I thought. It is a bit loud, but if your heater furnace or A/C kicks on, those are much louder. It’s a constant hum “white noise.” I had to run electricity to the crawl space so I put an outdoor lamp timer and a GFCI circuit for it in the garage. That way I won’t have to go into my 12” high crawl space to control it (I hate going in my crawl space!!), and it’s on a timer so it’s only on from 9am to 9pm so it won’t disturb our sleep. I tried to mount it from the outside, but the guts plus ac cord didn’t fit in my opening. It’s more protected from the elements and probably cuts down on noise inside the crawl space, so it’s probably better to install it in your crawl space.

Still running after 3 years. Low noise. I can hardly hear it when in crawlspace. Great product. Suction is not super strong but good enough for crawlspace.

In the photo is my crawl space fan, it has been in use since mid-2018 and shows no signs of giving up anytime soon. As some other reviewers have mentioned using soft material between the mounting surface will help somewhat for the noise transmitted into the structure. For my single fan installation noise wasn't really an issue, added insulation and can't hear the fan indoors at all. Main thing is that the fan and humidistat work well and perceptibly reduced humidity in the crawl space. If this one ever stops working I will buy the same product again!

Installed this fan in a client’s crawlspace in May 2025 and has already failed. Tried to contact customer support with no success. I would not recommend this fan. Another note, both inlet and outlet fans are loud. Sounds like a drone hanging out in the crawlspace.

I have this in a crawlspace under my office and the hum of the fans are louder then I expected. Also the Humidistat is pretty inaccurate. It tends to be about 10% percentage point higher then 2 other humidistat's I've tested down there. It also fluctuates greatly and I've read it can be because of the metal housing around the fan. Over all just a fair fan! I do love that I can turn it on and off via the app i just wish the humidity readings were more accurate and it were a bit quieter.