Dehumidifier for Tool Storage: Moisture Control

Why moisture matters for metal tools

Metal tools rust when moisture in the air condenses on their surfaces. A dehumidifier removes moisture from the air, which helps keep surfaces dry. The key is to control moisture, not to rely on a specific humidity number. The EPA explains that the key to mold control is moisture control, and the same idea applies to keeping metal from corroding.

For advice on mold and moisture in your home, read the EPA's mold pages and the CDC's mold page. This article focuses on shopping for a dehumidifier, not on cleaning or structural issues.

• Look for a dehumidifier with a stated capacity in pints per day that matches the size of your garage, shed, or workshop.
• Consider a unit with a continuous drain hose or a pump if you have a floor drain nearby.
• Check the maker's page for the operating temperature range if your space gets cold in winter.

Reading capacity labels on listings

Dehumidifier listings state capacity in pints per day, which is the amount of water the unit can remove in 24 hours under test conditions. The U.S. Department of Energy (DOE) defines how this is measured. Since 2020, the test uses cooler conditions, so a unit's stated capacity may be lower than older models with the same look. This is a label, not a promise of how fast your space will dry.

The ENERGY STAR program explains that the capacity you need depends on the size of the space and the conditions without dehumidification. For a garage or shed, a larger space or a space that feels damp may need a higher capacity. This site groups guides by capacity, such as 50 to 99 pints and 100 pints, to help you compare listings.

• A small workshop or shed may fit a smaller capacity unit, while a large garage may need a higher capacity.
• If the space feels damp or has a musty odor, consider a higher capacity within your budget.
• Read the maker's page for the conditions under which the capacity is stated.

Drain options for garages and sheds

A dehumidifier collects water in a bucket, but for a garage or shed you may not want to empty it often. Listings may say 'pump included' or 'continuous drain.' A pump lets you route water up and out, while a continuous drain uses a hose to a floor drain or outside. Read the maker's manual for how to set up either option.

If your space has no floor drain, a pump model can push water to a sink or outside. If you have a drain nearby, a gravity drain hose may be enough. This site has guides for dehumidifiers with pumps and for drain options.

• Check if the listing includes a drain hose or if you need to buy one separately.
• For a space without a floor drain, a pump model may be more convenient.
• Read the maker's page for hose length and pump lift height.

Cold spaces and operating range

Garages and sheds can get cold in winter. The ENERGY STAR program notes that if temperatures typically fall below 65 degrees Fahrenheit, you may want a product specified for lower temperatures. Frost can form on coils and affect performance. Some units have an anti-frost sensor that turns the unit off automatically.

Read the maker's page for the operating temperature range. This site cannot tell you a specific temperature range for any unit; that information is on the listing or the maker's page. For more on low-temperature operation, see this article.

• Look for a unit with an anti-frost sensor if your space gets cold.
• Consider a desiccant dehumidifier if you need low-temperature operation, but read the maker's page for details.
• If the space is unheated, check the maker's stated operating range before buying.

Energy Star and efficiency

The ENERGY STAR mark is a program that certifies products for energy efficiency. According to ENERGY STAR, certified dehumidifiers use more efficient coils, compressors, and fans, and use 20% less energy than conventional units. This is a program, not a promise of a specific energy bill.

If a listing says 'Energy Star,' you can check the model on the ENERGY STAR product finder. This site has a guide for Energy Star dehumidifiers.

• Look for the ENERGY STAR mark on the listing or the maker's page.
• Use the ENERGY STAR product finder to verify a model's certification.
• Energy efficiency is one factor; capacity and drain options matter too.

Placement and care in tool spaces

Place the dehumidifier on a level surface, as the manual describes. Keep vents clear and allow space around the unit for air circulation. Clean the filter as the manual describes, and empty the bucket or check the drain regularly.

For a garage or shed, consider a unit with wheels or handles if you need to move it. Read the maker's manual for care instructions. This site has a guide on placement tips.

• Keep the unit away from walls and obstructions.
• Clean the filter regularly to maintain airflow.
• Store the unit according to the manual if you don't use it year-round.

What to pick for your situation

Questions

What does pints per day mean on a dehumidifier listing?

Pints per day is the amount of water the unit can remove in 24 hours under test conditions set by the U.S. Department of Energy. The number is a label, not a promise of how fast your space will dry.

Do I need a pump for a garage dehumidifier?

A pump is useful if you have no floor drain and want to route water up and out. If you have a drain nearby, a continuous drain hose may be enough. Read the maker's manual for setup.

Can I use a dehumidifier in an unheated shed?

Check the maker's page for the operating temperature range. Some units have an anti-frost sensor for cold conditions. This site cannot tell you a specific range.

Does an Energy Star dehumidifier use less energy?

ENERGY STAR certified dehumidifiers use more efficient components and use 20% less energy than conventional units, according to the ENERGY STAR program. This is a program, not a promise of a specific bill.

How do I protect tools from rust?

Controlling moisture is key. A dehumidifier removes moisture from the air, which helps keep metal surfaces dry. For mold and moisture guidance, read the EPA and CDC pages linked in this article.