The crawl spaces under our houses are vulnerable to a lot of problems relating to poor air quality, the most problematic usually being high humidity due to a lack of ventilation. It is this problem which leads most people into looking to buy a crawl space dehumidifier.
High humidity in your home’s crawl space can lead to a lot of unpleasant consequences, such as mold problems, pests, structural damage, heavy odors, allergy triggers, and more. As a result, taking proper care of your basement crawl space moisture problems is one of the most important things any home owner should do. Yet, a lot of people neglect to do so.
Closing up this vast area is one of several highly effective and energy efficient ways to make sure your home is more comfortable and healthy. However, if you opt for closing this area (crawl space encapsulation), you still need to take care of its humidity and ventilation first. Simply insulating your crawl space without considering how you will manage its excess humidity with an air purifier can be as disastrous as leaving it as it is.
So, how does one go about dehumidifying their wet crawl space? There are a ton of dehumidification products on the market, but they are all designed for different environments and different rooms. What makes a model that is suitable for this area different from others? There are several key things to consider:
The noise levels of the type of dehumidifier you would usually locate underneath your home isn't as relevant as the noise output of smaller models. Obviously, that doesn’t mean that you should buy a model that sounds like a freight train – you don’t want to hear it from up in your home – but you don’t need to care as much about your dehumidifier’s exact noise level.
Your dehumidifier needs to be powerful enough to dehumidify the entire crawl space. These areas are of a considerable size as they cover the footprint of your entire home. Their square footage is significant, but they are also not as tall as a room. Simply put, measure the volume of the space beneath your home and decide on a model that is powerful enough to cover that volume, but isn’t unnecessarily strong. 70 pints of moisture per day is usually sufficient although 95 pints is perfect for larger areas. Dehumidifer performance is rated at either pints per day or pints per 24 hours.
Power is one thing, but you are also interested in the dehumidifier’s efficiency. These devices are designed to work for long durations, so you want it to be as efficient in its energy consumption as possible whilst it works to remove excess moisture.
Crawlspace dehumidifiers need an efficient continuous drainage system. If you were just buying this appliance for your kitchen, then using the onboard bucket wouldn’t be a big deal. But you certainly don’t want to have to make a trip downstairs a couple of times per day each day, so make sure that you choose a model that has a convenient continuous drainage system.
The appliance needs to work at low temperatures and have an auto defrost function. The auto defrost systems prevents the inner workings of the machine from building up frost and working at low temperatures is something that is often required in a basement and crawl space.
An auto reset function is also pretty important for this type of dehumidification appliance. This function restarts the device after a power outage, keeping all of its original functions. This is great, since even if you are home it saves you an unnecessary trip underneath your property.
So, which are our top 5 picks for the best crawl space dehumidifiers on the market right now? We will list them below for your convenience, but you don’t need to constrain yourself to just those 5 models – the market offers a lot of different options for a variety of different environments. We hope our list at least gives you a good starting point for what you are looking for, if not an outright decision as to the best dehumidifier for your crawl space.
This Sentinel HD55 model from AlorAir is our starting pick for a commercial grade crawl-space dehumidifier. It has an Energy Star rating which alone demonstrates its capabilities. It is suitable for much more than just the area beneath your home – as it can also perform well in a warehouse, an office, an apartment or a shop, and other such places.
As a 55 pint model, the Sentinel HD55 has a coverage area of around 1300 square feet, depending on the humidity levels. This is a nice average power level which can cover both smaller but very damp crawl spaces, as well as larger, but not so damp ones.
A dehumidification appliance such as this one will be of great help in battling mold growth, mildew, heavy odors, or corrosion, which are so easy to form and develop in a non vented crawl space.
Next on our list is another AlorAir model – the Sentinel HDi90. The chief difference you will notice immediately from our previous entry is the fact that this is a 90 pint model. As such, this model easily covers much bigger areas than the smaller Sentinel model and most other models.
This unit is designed for huge areas – with its 90 pint power and 210 CFM (Cubic Feet per Minute) coverage, the HDi90 is the perfect option for any area up to 2,600 square feet. And the great thing is that even with its immense power, the HDi90 is still surprisingly efficient. With a 2.88 L/kWh and only 5.56 amps the HDi90 will do its job both as effectively as possible and as efficiently as possible.
Best of all, this model has a built in condensate pump (make sure you order the pump version) which many owners will find essential.
Another great option for big crawl spaces, this Dri Eaz compact model pumps 75 pints of water from the air every 24 hours. It has two different operating modes – humidistat and continuous operation.
The humidistat mode works by maximizing moisture removal efficiency. It maintains a preset humidity level and adjusts its operation accordingly to the current humidity levels.
The continuous operation mode is exactly what it sounds like – you set the device to work continuously at one power setting until you say otherwise. This is ideal when you want to drop the humidity levels as fast as possible with zero downtime.
It also comes with an included 40’ drain hose, a 25’ power cord and a 3M HAF filter. This little dehumidifying dynamo displays real time inlet and outlet temperature and relative humidity and has a built-in humidistat.
It is much smaller than other models of its power class, making it great for crawlspaces and other places where it might be required. It is also much easier to transport if you need it for more than one location.
Last but not least on our list is this 70 pint appliance from Ivation. This IVALDH70PW model is a more standard type of dehumidifying appliance, one that would fit well inside the home as well, not just in the area underneath your house.
Its specifications make it well suited for a crawl space too, however, which is why we have to mention it. If you are looking for a portable dehumidifier which would need to temporarily be used in this location but can be moved inside your home after that, this Ivation model is the perfect option.
It is powerful enough to easily take care of all the mold, mildew, dust, allergens, and odors in any area or home of up to 4500 square feet of footprint (depending on the level of dampness too, of course). It has a programmable humidistat, a hose connector, an auto shutoff and auto restart function, as well as a bright and easy to use LED display. It’s not the quietest model on the market, but that shouldn't put you off given the location where you intend to use it.
High levels of humidity and condensation are a serious problem for your home's foundation. Since many homes in the US are constructed from timber, the presence of excess moisture in crawl space air is the perfect breeding ground for wood rot and other forms of timber decay in your floor joists. You can also expect an outbreak of mold and mildew to form if the levels of humidity are high enough.
Over time, you will find that your foundation becomes weakened which in turn can affect the overall integrity of your property. In the worst case scenario, this moisture could rise through the construction of the crawlspace and enter the interior of your home itself, requiring water damage restoration.
Usually for several reasons. Due to its location, your crawlspace is in close proximity to the ground or dirt floor which naturally contains a significant quantity of water.
If there is a crack in your crawl space's walls and you lack a vapor barrier, this water can enter this area which will raise the level of internal humidity. Couple this with cool temperatures and insufficient ventilation (a lack of fresh air or outside air) and you are left with damp.
Non-vented crawl spaces are particularly susceptible to this problem due to the lack of dry air. The presence of standing water can also quickly raise the level of humidity in this environment.
Simply put, by lowering the level of humidity and pumping moisture out of the environment. In combination with sealing any cracks within the structure of your crawlspace, you will benefit from a more comfortable living environment and avoid costly repairs.
Musty odors will quickly become a thing of the past as the internal air volume beneath your house begins to dehumidify, loses moisture and becomes dry. A reduction in allergies and improved health in addition to preserving the structural integrity of your home are just some of the many benefits you can look forward to.
A wall mount or ceiling mount is the most common installation option for many home owners. We suggest surveying the installation area to find a location that offers good access for maintenance and doesn't provide an obstruction.
It is also important to keep in mind how you intend to dispose of the moisture that is collected from the atmosphere, which is why we recommend choosing an installation location that is in close proximity to a drain if possible.
It is advisable to locate your new dehumidifier as centrally as possible, as this will allow it to operate more efficiently which should in turn remove moisture much faster with a more even distribution throughout the area.
Companies such as Dri Eaz also sell wall mounts for their product range so be sure to buy a set if you plan on a wall mounted installation.
Finally, we recommend removing as much dirt, dust and debris from the area as possible to prevent it from prematurely clogging the appliance's filters. Doing so should reduce the frequency that each filter needs to be removed for cleaning.
These appliances are designed to run for extended periods of time without so much as an inspection. Once installed, there is no requirement to perform any maintenance other than to change the onboard air filters in conjunction with the recommendations detailed within the owners manual.
There are our 5 suggestions for the best crawl space dehumidifier. Depending on the size of your crawlspace, as well as its dehumidification needs, different models can be better suited than others - but we firmly endorse the AlorAir Sentinel as our top pick. The other models we have tested also make great choices as do the Santa Fe Thermastor and Sante Fe Compact range as well as the Aprilaire 1850 dehumidifier range. It should be noted that all of these models can also be used as a basement dehumidifier.
You might have noticed that we included the Ivation 70 pint model in this review for its versatility – it isn't specifically designed as a dehumidifier for crawl space - but it might be a good choice for those who live in smaller homes and don't need such a heavy duty option.
If you are looking for a general guide to the best dehumidifiers which includes several reviews - we suggest that you check out our comprehensive dehumidifier buying guide.