Blog23 May 2016

What is the difference between a refrigerant and a desiccant dehumidifier?

The need for portable dehumidification equipment varies across a range of applications including construction sites – where drying times are accelerated – to museums and art galleries, where units are used to protect priceless works of art. Regardless of the environment, a dehumidifier works by removing moisture from the atmosphere and thus allowing the relative humidity (RH) to be controlled within the required parameters.

Other important factors that need to be considered include:

– the power supply available

– the relative humidity required

– the ambient temperature in which the units are required to operate

– the position where to units will operate from.

Refrigerant dryers work by drawing damp air from a particular area into the unit itself, before passing it over cold evaporator coils and bringing the air below its dewpoint temperature. The resultant condensation can then be collected from the coils and allowed to drain.

Desiccant dryers operate by circulating air through a rotor which contains a moisture-absorbent material. Water is extracted from the atmosphere and replaced by dry air. The moisture collected by the wheel is removed by using heat to encourage the vaporised moisture to exit a room or building via ducting.

It’s difficult to directly compare the performance of both models, as each type of unit offers the end user a number of unique advantages. Desiccant units are generally capable of removing greater quantities of moisture per hour, but require larger power supplies and are therefore more expensive to run.

Operating temperature should remain one of your primary considerations prior to hiring a dehumidifier unit, as the two types of product function differently at lower temperatures. Desiccants are adept in very low temperatures because the absorption process works regardless of temperature.

Refrigerant units are well suited to ambient temperatures above 5°C and will often use a mere third of the energy required by a desiccant dryer. These units are positioned within the area that requires dehumidification and are regularly used in applications such as building, construction, flood recovery, storage areas and museums.

Where a dehumidifier cannot be positioned within the area that requires drying, a desiccant can be the best solution as the air circulation can easily be ducted into areas such as storage tanks, machinery or vessels. For applications where a very low RH is required (below 40%), such as pharmaceutical production, desiccant units are usually the best solution.

In summary, for general storage or drying applications where the temperature is above 5°C, a refrigerant unit is often the best and most economical solution. When a unit is required to operate at low temperature conditions or if a low RH is required, desiccant units are usually the best option.

Whatever your application or process, Andrews Dehumidification have the expertise and knowhow to diagnose an appropriate solution before implementing it with minimal fuss. For more information on our service and hire fleet, or to get a quote from one of our trained sales team, call us today on 0800 611 211.

To read more about the differences between refrigerant and desiccant dehumidifiers, click here.

You can watch our video about how dehumidifiers work by clicking here.