The Eva-Dry E-500 is a low cost rechargeable desiccant dehumidifier. How it works is fairly simple. Inside of the device’s outer plastic shell is a chemical desiccant. In this particular model’s case it’s a silica gel. The silica gel adsorbs (“adsorb” is the scientific term for the process) moisture from the ambient air. When the gel reaches capacity (when it’s completely saturated and can longer adsorb moisture) you’ll need to plug the E-500 into a wall outlet to allow the desiccant to recharge. The electricity from the wall outlet heats up the desiccant and liberates moisture from it. After the desiccant is recharged the device is ready to adsorb moisture once again.
The E-500 isn’t the only low cost rechargeable mini desiccant dehumidifier manufactured by Eva-Dry. The E-333 is similarly priced (it’s actually a bit cheaper) and works exactly the same way. It also dehumidifies by adsorption and it also contains the same silica gel. Like the E-500 it has an “indicator window” that will indicate when the device needs to be recharged. The crystals (of silica gel) in the indicator window will change color over the course of several weeks as the device dehumidifies. When the desiccant is completely unsaturated the color of the crystals in the indicator window will be blue. When the desiccant reaches 100% saturation the color of the crystals will turn pink – this indicates that it’s time to plug in the device for it to recharge.
Although both the E-333 and E-500 work exactly the same and have exactly the same design there are a few notable differences between these two devices which we’ll discuss next. The first most obvious difference between them is that the E-500 is physically larger than the E-333. The E-500 measures 8 inches long, 2.5 inches wide and 5.5 inches high. The E-333 is slightly shorter – it’s only 6.25 inches long; slightly narrower – it’s only 1.25 inches wide; and it also doesn’t measure as high – it’s only 4.75 inches in height. The second, more important difference, is the fact that the E-500 has a greater capacity but a lower moisture removal rate than the E-333. Thirdly, the E-500 can dehumidify a larger area than the E-333, at least according to the manufacturer. We discuss all of these differences in much greater detail below.
Moisture Removal Rate
The E-500 removes 6 to 8 ounces of moisture every 4 to 8 weeks. The E-333 removes 4 to 6 ounces every 2 to 4 weeks. Two important deductions can be made from this information. First, the E-500 has a greater capacity than the E-333. It can adsorb as much as 6 to 8 ounces before needing a recharge. The E-333 can only adsorb 4 to 6 ounces of moisture before needing a recharge. Secondly, the E-500 adsorbs the same quantity of moisture as its capacity (6 to 8 ounces) in 4 to 8 weeks. The E-333 takes only 2 to 4 weeks to adsorb its capacity (4 to 6 ounces). To compare both devices’ moisture removal rate, let’s take the median of their manufacturer specified moisture removal rates (6-8 oz in 4-8 weeks and 4-6 oz in 2-4 weeks, respectively) and compare them. For the E-500 we have 7 ounces (right between 6 and 8 oz) in 6 weeks (right between 4 and 8 weeks) and for the E-333 we have 5 ounces (right between 4 and 6 oz) in 3 weeks (right between 2 and 4 weeks). Transposing the latter rate to the same timeframe as the former we have 10 ounces of moisture removal in 6 weeks for the E-333 and 7 ounces of moisture removal in 6 weeks for the E-500. Clearly, with all other variables being equal, the E-333 removes moisture at a faster rate than the E-500.
Area of Coverage
Eva-Dry specifies that the E-500 can be used in spaces as large as 500 cubic feet and that the E-333 can be used in spaces as large as 333 cubic feet. While we don’t disagree that you could use these devices in spaces as large as 333 and 500 cubic feet, our recommendation is that you don’t. The E-500 and E-333 have a multitude of uses but dehumidifying any reasonably sized space (and in this case we consider 333 cubic feet to be a a “reasonably sized space”) isn’t one of them.
The E-500 is a good option for any space that’s small and/or only mildly humid. We would go as far as saying that this type of device (a rechargeable desiccant dehumidifier) should not be used in any space in which you can actually feel humidity. Instead, it should only be used in spaces in which you can only smell (odors) and/or see (mold or mildew) the effects of humidity. If you have a bedroom, living room, large bathroom, etc. with perpetual tangible humidity then the E-500 is definitely not recommended. Instead we would recommend a full size compressor based dehumidifier. For smaller areas a small capacity 30 pint dehumidifier will suffice while for larger areas with more sever humidity a large capacity 70 pint dehumidifier will be necessary.
The E-500 should only be used in small damp spaces that may have odors or other signs of humidity (such as mold and mildew). Examples of these types of spaces include kitchen and/or bathroom cabinets, closets, boat cabins, refrigerators, etc. Recall that it doesn’t require electricity to operate (it only requires electricity to be recharged), making it a great option for spaces without easy access to electricity such as car trunks, safes, and the like. Speaking of safes, the E-500 is also a great solution for spaces that aren’t necessarily humid but absolutely need to stay dry. The best example of this type of space is a safe containing valuable documents, jewelry, etc. that aren’t necessarily damp but do absolutely need to be protected from moisture.
The E-500 normally retails for between $25 and $30 (approx.). The E-333 normally retails for between $15 and $20 (approx.). Which model you purchase will largely depend on whether you value the larger capacity of the E-500 or the greater moisture removal rate of the E-333. The E-500′s greater capacity and lower moisture removal rate make it the more convenient dehumidifier to use. You only need to plug it in to recharge it once every 4 to 8 weeks. The E-333 removes moisture more quickly on top of it having a smaller capacity. You’ll have to worry about plugging it in much more frequently (once every 2 to 4 weeks). That being said, despite the fact that it may be less convenient to use, our overall recommendation is the E-333. On top of the fact that it removes moisture more quickly than the E-500 it’s also smaller, lighter (making it more versatile in how it can be used) and perhaps most importantly, less expensive. Depending on the price of each device at the time of your reading this review, you could potentially buy two E-333′s for the price of one E-500. For our full E-333 review click here.
At approximately $30 the E-500 is only about $10 less expensive than the least expensive thermo-electric dehumidifiers on the market. Two such dehumidifiers, the Ivation IVADM10 and Gurin DHMD-210, both have a retail price of approximately $40. The IVADM10 removes up to 6 ounces of moisture per day and the DHMD-210 removes up to 8 ounces of moisture per day. These units are a much better option than either the E-333 or E-500 for small bathrooms or any other small space with mild but tangible humidity. The only downside of using this type of dehumidifier over using either the E-500 or E-333 is that they need to be plugged in to work and so won’t be a viable option for cars or any other space without access to a wall outlet for electricity.
Of course, if the space you need to dehumidify is large, is perpetually humid, or is anything more than only very slightly humid our recommendation is that you purchase a full size compressor based dehumidifier. For our buyer’s guide on this type of dehumidifier click here.
Finally, you may be comparing the E-500 to cheaper non-rechargeable disposable desiccant moisture absorbers, the most popular of which are DampRid products. We’ve reviewed two such disposable DampRid products thus far, the FG50T and the FG83LV. Like the E-333 and E-500, they also don’t need to be plugged in to dehumidify. They also use a desiccant chemical agent to remove moisture from the ambient air. Unlike the E-333 and E-500 they’re fully disposable. After their desiccants reach saturation you simply throw them away. You can’t recharge them for continual use and reuse. Why then would you even consider such a product over a device that can be continually recharged for reuse?
The only real reason why you might be tempted to buy either DampRid product is price. Both the FG50T and FG83LV retail for less than $10 (approx.). Keep in mind, however, that this will only buy you one tub of FG50T or one three pack of FG83LV. After they’re used up, you’ll need to replace them. As such, our recommendation is simple. If you feel as if that musty refrigerator, washing machine, kitchen cabinet, etc. you need to dehumidify is only going to require one purchase of either DampRid product then save your money and purchase the cheaper DampRid product. If, however, you believe that you’ll need to buy more than one tub of FG50T or more than one three pack of FG83LV to take care of any and all of the humidity problems in your home, we strongly recommend either the E-333 or the E-500 instead. Both of these devices do cost more (about twice as much for the E-333 and three times as much for the E-500) but at less than $30 (approx.) they’re still very reasonably priced. You’ll also be able to use and reuse them for up to 10 years. That’s a very long time and makes them a much better value over time.
So, in summary, we recommend the E-333 over the E-500 unless you absolutely value the E-500′s larger capacity over anything else. We recommend a thermo-electric dehumidifier such as the IVADM10 if your humidity problem actually involves tangible humidity but isn’t very severe. We recommend a compressor based dehumidifier if the space you need to dehumidify is large and/or perpetually and/or severely humid. And finally, we recommend either the E-333 or the E-500 over disposable desiccants in almost every scenario. Only purchase a disposable desiccant if you believe it’s only going to take one purchase of that desiccant for you to solve your humidity problem.