Desiccant vs Compressor for RVs: A Comparison

Understanding the two technologies

Dehumidifier listings usually name the type of technology the unit uses. Two common types are compressor and desiccant. A compressor dehumidifier works like a small refrigerator: it pulls air over cold coils, and moisture condenses into a bucket or drain. A desiccant dehumidifier uses a moisture-absorbing material, often a wheel, that rotates through the air and then through a heated zone to release the collected water.

The type matters for an RV because the space is small, the power supply may be limited, and the temperatures inside can vary widely. The listing title or bullet list usually states whether the unit is a compressor or desiccant model. If the type is not stated, check the maker's page or the product manual.

This article explains how to read those listing terms and what to consider for an RV. It does not compare measured performance, noise, or energy use, because those figures are not in the listings this site reads. For any specific model, read the maker's stated details.

Temperature considerations

Temperature is a key difference between the two types. Compressor dehumidifiers rely on cold coils to condense moisture. In cooler air, there is less moisture to remove, and frost can form on the coils. The ENERGY STAR buying guidance notes that if the space being dehumidified has temperatures that typically fall below 65 degrees Fahrenheit, you may want to consider a product specified for use at lower temperatures. Frost can form on the condensing coils below that point and may affect performance.

Desiccant dehumidifiers do not use cold coils, so they can operate at lower temperatures. For an RV that is used in cool weather, or stored in a cold climate, a desiccant unit may be a better fit. However, the listing may not state a specific operating range. If the temperature range is important to you, read the maker's page or manual for the stated operating conditions.

For an RV that is used mainly in warm weather, a compressor model may be sufficient. The listing may not state a temperature range at all, so you may need to ask the maker directly.

Space and weight

RVs have limited floor and counter space. Desiccant units are often smaller and lighter than compressor units of similar stated capacity, which can make them easier to store and move. Compressor units tend to be bulkier because they contain a compressor and coils.

When reading a listing, look at the dimensions and weight if they are stated. The listing title may not include these details, so check the bullet list or the maker's page. A smaller unit may fit better in a closet, under a counter, or in a corner of the RV. For more on placement, see our guide on dehumidifier placement.

Keep in mind that a smaller unit may have a lower stated capacity. The capacity is measured in pints per day, and the listing may state the capacity under a specific test condition. For an RV, a smaller capacity may be enough, but you should consider the size of the space and the moisture level. The ENERGY STAR guidance suggests that capacity depends on the size of the space and the conditions that exist without dehumidification. Learn more about capacity versus square footage.

Power and energy

RVs often run on limited power, whether from a generator, shore power, or batteries. Desiccant dehumidifiers use a heating element to dry the desiccant material, which can draw more power than a compressor unit. Compressor units use a compressor and fan, which may be more energy-efficient in some conditions.

The listing may state the wattage or amperage, but this site does not read those figures. If power use is a concern, read the maker's page or manual for the electrical requirements. The ENERGY STAR program certifies dehumidifiers that meet certain efficiency criteria, but the mark does not guarantee a specific power draw. You can check the ENERGY STAR product finder to see if a model is certified. See our explanation of Energy Star requirements.

For boondocking or battery use, a lower-power unit may be preferable, but the listing may not state the power draw. In that case, contact the maker for the electrical specifications.

Drainage options

Both types of dehumidifiers collect water in a bucket or can be set up for continuous drainage. In an RV, emptying a bucket may be inconvenient, especially if the unit runs while you are away. A continuous drain hose can route water to a sink, shower, or outside, but you need a drain nearby.

The listing may state whether a drain hose is included or if the unit has a pump. A pump can push water up and out, which is useful if the drain is above the unit. For an RV, a pump may not be necessary if you can place the unit near a drain. Read the listing for the drainage options, and check the maker's manual for the hose connection size and setup. Our guide on drain options explains the terms.

If the unit has a bucket, the listing may state the bucket capacity. This site does not read bucket size, so check the maker's page if that matters to you. A larger bucket means less frequent emptying, but it also adds weight.

Noise and operation

Noise can be a consideration in an RV, where the living space is small. Compressor units make a humming or buzzing sound from the compressor and fan. Desiccant units may be quieter because they have fewer moving parts, but they still have a fan and a rotating wheel.

The listing may not state a noise level in decibels. This site does not read noise figures. If noise is important to you, read the maker's page or manual for any stated sound level. Some listings may use words like 'quiet' in the title, but that is a marketing term, not a measured claim. Our article on noise levels explains what to look for.

Consider where you will place the unit. If it will run while you sleep, a quieter unit may be preferable. The placement tips in the maker's manual can help you position the unit for best airflow and minimal disturbance.

What to pick for your RV

The right choice depends on your RV usage patterns. If you camp in warm climates and have shore power, a compressor model may be a straightforward choice. If you use the RV in cool weather or store it in a cold garage, a desiccant unit may handle lower temperatures better. For more on low-temperature operation, see this comparison.

Consider the size of the space. A small RV may only need a small-capacity unit, while a larger RV with a bathroom and kitchen may need more capacity. The listing title often states the capacity in pints per day, but remember that the figure is based on a test condition. Read the maker's page for the conditions under which the capacity is stated. You can browse our best small dehumidifiers or best high capacity dehumidifiers for options.

Also think about how you will power the unit. If you rely on batteries, a lower-power unit may be better, but the listing may not state the power draw. Contact the maker for the electrical requirements.

Finally, consider the drainage. A unit with a pump can be more flexible, but it adds cost and complexity. A simple bucket may be fine if you can empty it regularly. See our best dehumidifiers with pump for models that offer that option.

What to pick for your situation

Questions

Can a compressor dehumidifier work in an RV?

Yes, a compressor dehumidifier can work in an RV, especially in warm conditions. However, in cooler temperatures, frost can form on the coils, which may affect performance. Check the maker's stated operating range.

Are desiccant dehumidifiers better for RVs?

Desiccant dehumidifiers can operate at lower temperatures and are often lighter, which can be advantages in an RV. However, they may use more power. Consider your typical climate and power source.

What capacity do I need for an RV?

Capacity depends on the size of the space and the moisture level. The listing states the capacity in pints per day, but the figure is based on a test condition. Read the maker's page for the conditions.

How do I drain a dehumidifier in an RV?

You can empty the bucket or use a continuous drain hose if the unit has that option. A pump can push water to a higher drain. Read the listing for the drainage options and the maker's manual for setup.

Do I need a pump for an RV dehumidifier?

A pump is useful if the drain is above the unit, such as a sink. If you can place the unit near a floor drain or use a bucket, a pump may not be necessary.