Is a calcium chloride product like Dri-Z-Air adequate to dehumidify our RV? Or should we use a plug-in dehumidifier? —Bruce, 2017 Sunseeker
I am not familiar with Dri-Z-Air so I went to their website. According to their MSDS (Material Safety Data Sheet), it is more than 90% calcium chloride, which is a crystal very similar to table salt. They recommend using one dehumidifier or tray every 10’ in an RV. The product claims to draw moisture to a 50% relative humidity, which is pretty good. You can find the product on Amazon here.
I have used DampRid for many years and found that to be very good at absorbing moisture, as well. According to their MSDS, it is 80%-90% calcium chloride, so I believe they are similar products. What I like about DampRid is the variety of products they have, from the hanging pack that can go in a closet to the larger buckets. They even have a moisture detection strip. You can find their products on Amazon as well here.
The downside of both products or anything else that uses calcium chloride as the base is there is not air movement with them. That means you can have pockets that can still get condensation, moisture, and mold such as cabinets, closets, under bed pedestals and corners around beds and furniture. Plus, calcium chloride products will only reduce moisture to 50% at max, which I would challenge unless you have about 10 buckets located throughout the RV. An electric dehumidifier draws in moist air and pushes dryer air out, and will reduce moisture down to 35% or lower.
What is the correct relative humidity?
Finding the right relative humidity for you is important and can vary. High humidity not only creates moisture but is a healthy environment for dust mites and mold. Low humidity creates dry air and increases the possibility of catching airborne viruses. It can also create dry skin and is irritating for owners that have skin rashes.
According to the National Asthma Council, the best relative humidity is between 30%-40%. However, mold will be inhibited under 70%
Tips to reduce humidity
The key to reducing humidity is limiting activities that create condensation, such as cooking, showering, and washing clothes. Hygrometers meter temperature and relative humidity. Find them on Amazon here.
Limit the amount of moisture in your rig by not boiling water or liquids when cooking. Limit or reduce showering time, and make sure your bathroom roof vent draws out steam and moisture. Ventilate the interior by using fans to move the air, and open overhead compartments or wardrobes to limit those pockets.
I sent Bruce a rough draft of this response and got this back, so I though I would update the post:
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