Complete Guide to Types of Dehumidification Technologies

Dehumidification technology has come a long way, offering various solutions to help you control excess moisture in your environment. However, with several types of dehumidifiers available, it can be tricky to understand how each works and where they perform best. In this guide, we'll explore the different types of dehumidification technologies, their applications, and the specific scenarios where each type excels.

Link to Types of DehumidifiersTypes of Dehumidifiers

There are a few main types of dehumidifiers, each with its own unique approach to pulling moisture out of the air: Refrigeration/Compressor Dehumidifiers, Desiccant Dehumidifiers, and Peltier (Thermoelectric) Dehumidifiers.

Link to 1. Refrigeration/Condensation Dehumidifiers1. Refrigeration/Condensation Dehumidifiers

Refrigeration or Condensation Dehumidifiers are the standard go-to for most homes in the UK, as they work best . They pull in humid air, cool it, and collect the resulting moisture.

Link to How They WorkHow They Work

Refrigerant dehumidifiers work by using a fan that draws humid air into the machine. This air then moves over coils cooled by a refrigerant. When the warm, damp air hits these cold coils, water condenses—much like dew forming on a cold soda can—and collects in a reservoir or drains away. The newly dried air gets reheated and then blown back into your room, feeling fresh and crisp.

Most residential refrigerant dehumidifiers operate effectively at temperatures as low as 5°C, and they work best between 5°C and 25°C. Below 5°C, moisture can freeze on the coils, reducing efficiency. Some models are equipped with an auto-defrost function to handle colder environments and prevent frost buildup. Although some advanced models feature a hot gas bypass to prevent freezing, it is not standard across all units.

Link to ApplicationsApplications

• Homes and Offices: These units are excellent for keeping living spaces comfortable. They help keep basements, bedrooms, and living rooms mould-free, especially in areas with high humidity.
• Construction or Decorating: These units help speed up drying times for materials like plaster or paint, and they're great after water damage, getting things back to normal faster.
• Swimming Pools: Indoor pools generate a lot of moisture. Large refrigeration dehumidifiers keep that in check, preventing mould growth and stopping poolside furniture and structures from rusting or corroding.

Link to Pros and ConsPros and Cons

• Pros: They're energy-efficient in moderate temperatures, easy to find, and versatile for both home and commercial use.
• Cons: They struggle at very low temperatures—the coils can freeze up—and the compressor and fan can be noisy, which might be annoying if you're after some peace and quiet.

Link to 2. Desiccant Dehumidifiers2. Desiccant Dehumidifiers

Desiccant Dehumidifiers use hygroscopic material—basically, stuff that loves to soak up water, like silica gel—to remove moisture from the air. Unlike compressor units, they absorb moisture rather than condensing it.

Link to How They WorkHow They Work

Humid air passes through a rotor or wheel coated with a desiccant material that absorbs the moisture. Over time, the desiccant gets saturated and needs to be regenerated—that's when a built-in heating element kicks in, drying it out so it's ready to absorb more moisture.

These units are great for cold environments where condensation dehumidifiers just can't do the job. They're also excellent at achieving really low humidity levels, which makes them perfect for certain applications that need precise moisture control. While advanced desiccants like Metal-Organic Frameworks (MOFs) and superabsorbent polymer-based composites are being researched to improve energy efficiency, most consumer units still rely on silica gel.

In very cold conditions, desiccant dehumidifiers can be more energy-efficient compared to refrigerant units, as the latter lose efficiency at lower temperatures.

Link to ApplicationsApplications

• Cold Spaces: Got an unheated garage or basement? Desiccant dehumidifiers are your best bet in these chilly conditions. They work well even below 10°C, keeping condensation, mould, and rust at bay.
• Small to Medium Spaces: Desiccant dehumidifiers are suitable for smaller areas where moisture needs to be controlled effectively, especially in cold climates.
• Flood Restoration: Desiccant units are ideal for urgent moisture removal after a flood. They work well, whether it's cold or warm, which makes them versatile for drying out residential areas quickly.

Link to Pros and ConsPros and Cons

• Pros: Highly effective in colder environments, capable of reducing humidity levels significantly, and quieter compared to compressor-based units.
• Cons: They use more energy than refrigeration dehumidifiers, and they tend to be pricier—both in terms of initial cost and operating expenses. Not suitable for very large spaces.

Link to 3. Peltier (Thermoelectric) Dehumidifiers3. Peltier (Thermoelectric) Dehumidifiers

Peltier Dehumidifiers are compact units that use the Peltier effect to remove moisture. They're not quite as efficient as the other types, but they do have their place, particularly for smaller spaces.

Link to How They WorkHow They Work

These dehumidifiers use a thermoelectric element to create a temperature difference—one side gets hot while the other side gets cold. Moist air passes over the cold side, moisture condenses, and it gets collected. The simplicity of the design is what makes these units attractive for tight spaces.

They're great when you need a quiet, compact dehumidifier that fits into a closet, a pantry, or some other tight spot. However, even in small spaces, they struggle to significantly reduce humidity levels, which limits their overall effectiveness.

Link to ApplicationsApplications

• Small Spaces: Closets, pantries, or small bathrooms are ideal for these units. They're small, and their limited capacity works well in tight quarters.
• Low Noise Requirement: If you need quiet—like in a bedroom or an office—a Peltier dehumidifier could be the right fit. Without a compressor, there's no loud noise to deal with.

Link to Pros and ConsPros and Cons

• Pros: Compact, quiet, and energy-efficient—perfect for small spaces where noise is a concern.
• Cons: They're low on efficiency, limited in capacity, and aren't powerful enough for larger areas or places with a high moisture problem.

Link to Comparison Table: Types of DehumidifiersComparison Table: Types of Dehumidifiers

Link to Understanding Dehumidifier Size and CapacityUnderstanding Dehumidifier Size and Capacity

When selecting a dehumidifier, it’s important to understand what "size" really means. The size of a dehumidifier isn't about its physical dimensions—it's all about how much water it can extract from the air in a day, known as the extraction rate. This extraction rate is measured in liters per day and reflects the amount of moisture the dehumidifier can remove under specific conditions in a 24-hour period.

The tank capacity is another aspect to consider. It refers to the amount of water the unit's storage tank can hold, typically ranging between 2 to 6 liters. A unit with a higher extraction rate will need more frequent emptying if the tank capacity is small, but some units offer a continuous drain feature to make life easier.

Link to Choosing the Right Dehumidifier SizeChoosing the Right Dehumidifier Size

• Small Rooms (e.g., Bathrooms, Bedrooms): For smaller rooms, an extraction rate of 8-12 liters per day is typically sufficient. Compact units, like Peltier dehumidifiers or smaller refrigeration models, work well in these spaces.
• Medium to Large Rooms (e.g., Living Rooms, Basements): For larger areas, you'll want a unit with an extraction rate of 20-35 liters per day. Refrigeration dehumidifiers are often best for these environments, especially if the temperature remains moderate.
• Very Large or Multi-Room Spaces: For open-plan areas or whole-house coverage, a dehumidifier with a 30-50 liter extraction rate is recommended. Refrigeration dehumidifiers with larger capacities are ideal, provided the temperature is suitable.

Link to Dehumidifier Size Recommendation ChartDehumidifier Size Recommendation Chart

Link to Special Considerations for Different EnvironmentsSpecial Considerations for Different Environments

Link to 1. Residential Homes1. Residential Homes

For most residential spaces, a refrigeration dehumidifier with appropriate capacity will work well. Maintaining relative humidity between 40-60% prevents mould and keeps the air comfortable. Look for models with built-in humidistats for better control.

Link to 2. Basements and Garages2. Basements and Garages

Basements and garages can get cold, especially during winter. Desiccant dehumidifiers work best here if the temperature falls below 15°C. However, if these areas are kept at moderate temperatures, a refrigeration unit will be more energy-efficient.

Link to Conclusion: Which Dehumidifier is Right for You?Conclusion: Which Dehumidifier is Right for You?

Choosing the right dehumidifier comes down to understanding your environment, the level of moisture control needed, and the specifics of the space you're dealing with. Refrigeration dehumidifiers are versatile and affordable, making them great for most residential settings. Desiccant units excel in cold environments and are effective in handling moisture in smaller, chilly areas. Peltier dehumidifiers, while compact and quiet, are best reserved for small, enclosed spaces with mild dampness.

Keep in mind the extraction rate, tank capacity, and the specific needs of each room when selecting a dehumidifier. By doing so, you can ensure that your home stays comfortable, healthy, and free from the adverse effects of excess moisture.