V2D

We had our crawlspace encapsulated last year and they didn't install an exhaust fan. Pretty soon we started to get the "cat pee" smell in the house that a lot of people seem to experience, which is actually ammonia being released from the soil. I didn't want to pay to have them come back and install a fan (which they should have done originally, but I didn't know that at the time), so I bought the Tjernlund V2D to install myself. When I unboxed the fan it looked good and didn't feel cheap. I noticed that the frame was a little warped, but it easily flattened out when I screwed it in place, so this wasn't a big deal. Installation was pretty easy, but will vary depending on your situation. The vent opening I chose was larger than the fan, so I used some scrap plywood to make a frame. I secured the wood frame to the cinderblock with concrete screws and then secured the fan to the wood frame. I had to run a short extension cord to reach an outlet. Not ideal, but the fan has a very low amp draw. We have a dehumidifier in the crawlspace (part of the encapsulation) and I was only concerned with evacuating the ammonia, so I set the fan to always run and it's been running constantly for 8 months and still seems to be running like new. The fan evacuates enough air that we're no longer getting air leakage into the house and we haven't smelled ammonia in the house at all since installing the fan. Yay!! When it's running you can hear it outside within maybe 25 feet. Inside you can faintly hear it if you're standing within a couple feet of it, otherwise you'd probably never notice. Even outside the sound isn't obnoxious though. Basically sounds like two big PC fans, which is basically what I'd imagine they are. We had to stop the ammonia smell from getting into the house, but I didn't want a huge hassle installing a fan and I didn't want cheap junk that had to be replaced after a few months. Overall I'm extremely satisfied with the fan.

I’ve used these crawlspace fans for years and they last a long time they’re quiet and they do the job of moving air through crawlspace so you don’t have a development of mold and the iris and stacked that very high-quality and they work really well with the thermostat and the humidistat in them and they’ll come on when they’re needed definitely buy these.

I purchased this fan powered vent to pull air out of a crawl space underneath only one section of my house which is just a couple of hundred square feet. The unit is very easy to mount because it has a large (over sized) flange with a long hole for setting screws to mount the flange. I have it mounted on a hinged wooden door that opens the crawl space to a hallway in my basement. I have found the fan to be silent, but effective. Since purchasing the fan I've reduced humidity from an average of about 77% down to a range of 50-60%. I have used another humidity alarm and a humidity data logger to measure the humidity. When using the built in humidistat I found three problems. The first is that I think it is just inaccurate. If I set it for 30% the fan shuts off when two other devices located approximately 8" from it show the humidity at about 46% to 50%. I don't expect it to be accurate to 1% but it's off from the other two by 16% to 20%. The second, probably related issue, is that measuring humidity between two fans created skewed results because the air pressure is off from the flow of air because of the fans. The fix for this is that this unit should really come with a cable and a remote sensor to place at least a few if not several feet away. The third is that the hysteresis from the humidistat (hygrometer + controller) for the fans is far too wide. In understand that any sensor should, for example, when set to 30% RH turn on at 30% and perhaps turn off at 27% and then perhaps not back on again until it rises to say 33% (6% margin for hysteresis) so that the fan is not constantly cycling on and off. That said, my experience is that the margin is close to 20%. This means that the device runs excessively longer than it needs to (when the humidity is far below what it needs to be) or if set higher, doesn't come on until it rises above what I want it to be. Overall I am impressed with the fan and mounting/flange, but the humidistat is not well designed. My plan will be to bypass the humidistat and have a SCADA system take over turn the fan on and off with a remote hygrometer.

As a contractor I have put in probably 12 to 15 of these units underneath houses no complaints. The hydrostatic sensor works perfect perfectly is my go to with this kind of work.

The Tjernlund V2D UnderAire crawl space fan has completely saved our home from the many possible problems of excess moisture (mold, damp musty air, etc). Using this fan has resulted in much better air quality in our home!! It has been raining way more than normal where I live, and our house was starting to smell EXTREMELY musty from the moisture in the crawl space (we have a forced air furnace, so the air was seeping into the ductwork and being pushed into the house). My husband cut two circular holes just above the sill plate and mounted this fan there in the crawl space. We set the humidistat at the recommended setting we found online, of 50. It ran constantly for a good few weeks to get the moisture under control, and now just comes on as needed. Runs more when it's raining and less when it's not... no need to ever unplug or turn on or off. It's been a lifesaver! And no more musty smell! I would highly recommend this fan to anyone with similar issues. A couple things to note though: we put bug screen over the holes to prevent insects from getting in, and put dryer vent covers over the holes to make sure no rain could get in, and it worked out perfect! Also, don't use with another open vent for airflow... it will suck moisture in and you will just keep the problem going. Even without the fresh air, this thing really works!! I would buy again! THANK YOU TJERNLUND!!

I almost didn't buy this unit after one customer complained about it being noisy. I'm glad I pulled the trigger because this is a very good unit! The fans are "not" noisy and in fact I was impressed with how quiet they are. I can not hear the fans at all when in the house and standing directly over the unit located in the crawl space. I can hear them when I'm out side but need to be within about 10-15 feet of them. For this reason, I installed them in a location away from my patio and porches so it isn't an issue. Before installing, I put weather strip on the inside of the metal all around the perimeter. I used 1/2" thick weather strip. This allowed the unit to easily mount against the cement block and wood sill board without any problems. The top two screws went into the wood sill and the bottom two screws went into the cement blocks. The weather strip provides a nice seal and prevents vibration transfer to the house. A very good unit and works well. I can tell the fans are of high quality and the design is solid. Only suggestion would be to have the manufacturer include some rubber grommits in with the packaging for further isolation. Not necessary but might help some peoples install.

We spent over $20k on a crawlspace encapsulation at our cottage only to discover the emergence of a terrible smell inside the cottage. To me, it smelled like a bunch of dirty dishrags had been left out. To another person, the smell resembled cat pee. The encapsulation included two sump pumps but no dehumidifier or vent fan. We weren’t sure if the smell was from the sump pumps or from off-gassing. Regardless, it was unlivable in there. After doing a ton of research into the cause and remedy, and after reading a review here from someone who seemed to have a similar problem, we purchased this vent fan and installed it in the crawlspace window using plywood and a light-weight cover to prevent rain and snow from getting into the crawlspace through the fan. It has been running for almost a week and has completely eliminated the smell so far. You can smell that same odor in the air blowing out of the crawlspace through the vent van, so I’m fairly confident this was the right solution. Some reviewers mentioned the fan is extremely loud. I disagree. You can definitely hear it running when outside or if there is not a sound inside the cottage, but it’s more of a low hum than an obnoxious industrial fan sound, which is what I was expecting from some of the reviews. I’d venture to say it’s more of a soothing sound than a nuisance. I would highly recommend anyone experiencing a similar issue try this vent fan to see if it helps.

We bought 2 of these for our ranch home crawl space (CS) as our property is very wet and we have areas in the CS that have measured 30% moisture at times. If you have electrical outlets to use great - I am lucky enough to have a Dad that does electrical and he just had to find power sources - our easiest were under our kitchen sink area and near the water heater and installed outlets. We installed both units in existing vent spaces in our brick foundation. That was it! Unless you are standing directly next to them and know what to listen for you can't hear them running at all. I think people who say they are noisy must not install them correctly. One is on our bedroom wall and we can't hear it at all. The other is under the kitchen sink window and I can only hear it from inside the house very late at night when the house is dead silent. We have been running them for 2 months now - we live in the center of South Carolina where humidity is a given but they still turn off and on regularly. I am contacting the manufacturer to see whether we should adjust the humidity setting from the recommended 50% since we live in a high humidity environment. I will add to this review after I get an answer if it is pertinent.

Product was much more solid than I expected good quality materials. Easy to install. The humidity sensors work as described , I had a humidity gauge all ready set up and the fans turned on at the proper settings. It also shut itself off when temperature dropped below 34 degrees. The fans ran for 24/7 for the first week without a problem until I could install a timer. The musty smell is now gone in the crawl space and and air quality has improved greatly.

Easy to install. Runs reasonably quiet.

It works great. Took 5 weeks to arrive. Dropped humidity until desired level was reached. Easy to install and it can be barely heard in the room above the crawlspace even if the house is quiet. I’ve only had it installed 2 weeks now so can’t speak on the reliability. I chose it over the Durablow model because it would arrive 4 days quicker but in reality this was the slowest Amazon delivery ever. Even longer than light bulbs that were shipped on a boat from China.

The fan is just as per ad - good quality components. I was able to install it in the crawl space vent with some adjustments to my location. The fan is strong enough to vent the damp air.

Not quiet, as advertised...it has a pulsing whine that I can hear through my floor, as I have it installed in my crawlspace to vent the air. If it wasn't advertised as quiet I would not have bought it, and so I either have a lemon, or it is falsely advertised.