Dehumidifiers USA
   

Dehumidifiers Explained

How air to air dehumidifiers work

Commercial Dehumidifiers - ideal for heavy duty dehumidification in relatively large areas. They operate in either moderately damp to extremely wet areas in need of moisture removal. Use them to improve storage conditions, maintain fresh locker rooms, safeguard stored goods from mildew, control the environment of computer rooms or to prevent water damage to building foundation and insulation, and prevent dripping condensation from pipes.

Portable refrigerant dehumidifiers

Portable refrigerant dehumidifiers

Portable refrigerant dehumidifiers such as the CAPTURE 65L pictured below/right, remove moisture from the air by capturing small molecules of water vapour released from carpets, wood, plaster and other structural material during the drying process.

Refrigerant dehumidifiers are combined with air movers to form the foundation of an effective drying system. Dehumidifiers USA also stocks desiccant portable dehumidifiers.

Portable desiccant dehumidifiers

Portable desiccant dehumidifiers

Desiccant dehumidifiers such as the ASE 200 solve difficult or stubborn restoration problems including drying of structural materials, such as concrete floors, plastered walls, cavities and even document drying such as books. They are also ideal for industrial drying applications such as surface preparation prior to applying.

They feature a desiccant honeycomb rotor coated with a rare silica gel to capture water vapour from damp air. Warm, dry air is vented to the area being restored and moisture laden air is vented outside using 4" diameter duct.

The main advantages over refrigerant dehumidifiers is that desiccants produce desert dry air as low as 1 % RH and they can also operate in extreme cold, as low as zero degrees - great if no heat is available on site.

Dehumidifier Glossary

Actual vapour pressure - the partial pressure exerted by the water vapour present in a parcel. Water in a gaseous state (i.e. water vapour) exerts a pressure just like the atmospheric air. Vapour pressure is also measured in millibars.

Dehumidification - the process of removing moisture from the air or other materials.

Desiccant - a substance such as calcium oxide or silica gel that is used as a drying agent.

Dew point - the temperature air must be cooled to in order for saturation to occur, producing water in the form of dew or condensation. The dew point temperature assumes there is no change in the air pressure or moisture content of the air.

Dry bulb temperature - the actual air temp.

Evaporation - the change of liquid water into water vapour. Moisture evaporates due to differential vapour pressure, the larger the vapour pressure differential, the faster the drying.

Humidistat - an instrument that indicates or controls the relative humidity of the air.

Hygrometer - an instrument that measures atmospheric humidity.

Relative humidity - the ratio of the amount of water vapour in the air at a specific temperature to the maximum capacity of the air at that temperature.

Relative humidity is expressed as a percentage and can be computed in a variety of ways. One way is to divide the actual vapour pressure by the saturation vapour pressure and then multiply by 100 to convert to a percent.

Saturation of air - the condition under which the amount of water vapour in the air is the maximum possible at the existing temperature and pressure. Condensation or sublimation will begin if the temperature falls or water vapour is added to the air.

Saturation vapour pressure - the maximum partial pressure that water vapour molecules would exert if the air were saturated with vapour at a given temperature. Saturation vapour pressure is directly proportional to the temperature.

Wet bulb temperature - the lowest temperature that can be obtained by evaporating water into the air at constant pressure. Wet bulb temperatures can be used along with the dry bulb temperature to calculate dew point or relative humidity.


Calculating the correct number of refrigerant dehumidifiers for your water loss

A technically competent person can determine the best drying options with regard to load, performance of drying equipment and the ongoing monitoring of the drying envelope by using a psychrometric chart. The use of a thermal hygrometer will give readings of temperature in Celsius and Relative Humidity which allow the calculation of the Specific Humidity and then the total moisture load can be calculated using the equation below.

By knowing the total cubic capacity of the area to be dried, the moisture load by weight is calculated by:

Specific Humidity (kg/kg) x Total cubic capacity = total moisture load (kg) 0.833.

The total moisture load can be divided by 24 to indicate the total airborne moisture available to be removed within an hour. Divide this by the collection rate of each different class of refrigerant dehumidifier and you will be able to assess how many dehumidifiers you need of each class to do the job.

Calculating Requirements for Water Damage Restoration

Normally two to five air changes per hour (ACH) are recommended for water damage restoration applications.

  1. Calculate the volume of the structure in cu. ft. (L x W x H).
  2. Calculate the SCFM for one air change (volume / 60).
  3. Calculate the dehumidification capacity required (SCFM x ACH).

Example: A multi-story building measuring 100'L x 50' W x 50'H has received water damage due to flooding. You need to provide dehumidification capacity for three air changes per hour (ACH).

  1. Volume = 100 x 50 x 50 = 250,000 cu. ft.
  2. SCFM = 250,000 / 60 = 4,167 SCFM
  3. Dehumidification capacity = 4,167 SCFM x 3 ACH = 12,501 SCFM

This capacity could be provided using three 5,000-CFM dehumidifiers or one 15,000-CFM dehumidifier Use this same formula to calculate the capacity needed for other dehumidification applications in buildings by changing the A CH value.


Phoenix 200 - Refrigerant Dehumidifier (Class 1)

Phoenix 200 Refrigerant Dehumidifier

40 - 48 Litres per day@saturation

  • Height: 1016mm
  • Width: 508mm
  • Depth: 457mm
  • Power Consumption: 851 Watts

The Phoenix 200 MAX is one of the most effective and versatile drying devices available on the market today. When you combine this performance with the multiple ducting and air filtration options, it is easy to understand why the Phoenix 200 MAX is considered the ultimate in low grain refrigerant dehumidification.


Capture 65L - Refrigerant Dehumidifer (Class 1 +)

Capture 65L Refrigerant Dehumidifer

Up to 65 Litres per day @ 30°C RH80%

  • Height: 810mm
  • Width: 540mm
  • Depth 540mm
  • Power Consumption: 820-980 Watts
  • Weight: 45kg

The Capture 65L is the newest offering direct from Dehumidifiers USA. Made with a highly robust roto-moulded hard plastic casing, this quality machine gives outstanding performance. Incorporating a digital control panel, for setting required drying parameters, and automatic pump-out, you won't find better value for money.


EBAC CD35 - Refrigerant Dehumidifier (Class 4)

EBAC CD35 Refrigerant Dehumidifier

7-10 Litres per day@saturation

  • Height: 630mm
  • Width: 333mm
  • Depth: 400mm
  • Power Consumption: 627 Watts

The Ebac CD35 is a no-nonsense, go-anywhere, portable dehumidifier. Rugged enough for industry shops and store rooms, efficient enough to dry sensitive computer centres or archival storage.


EBAC Kompact - Refrigerant Dehumidifier (Class 4)

EBAC Kompact Refrigerant Dehumidifier

18 - 20 Litres per day@saturation

  • Height: 615mm
  • Width: 508mm
  • Depth: 488mm
  • Power Consumption: 750 Watts

The Ebac is no-nonsense, go-anywhere, portable dehumidifier. Rugged enough for industry shops and store rooms, efficient enough to dry sensitive computer centres or archival storage.


Arida 1500 - Refrigerant Dehumidifier (Bucket) (Class 1)

Arida 1500 Refrigerant Dehumidifier

35 - 45 Litres per day@saturation

  • Height: 880mm
  • Width: 520mm
  • Depth: 495mm
  • Power Consumption: 627 Watts
  • Weight: 40kg

The Arida 1500 dehumidifier is among the most advanced air dehumidifiers currently available. The rotation-formed plastic casing is highly resistant to impacts and breakages. It is also fire-resistant and extremely resistant to mechanical damage. A large, clear operating panel and a cable winder make the unit very easy to use.


Arida 1500 P - Refrigerant Dehumidifier (Pump Out) (Class 1)

Arida-1500-P-Refrigerant-Dehumidifier

35 - 45 Litres per day@saturation

  • Height: 880mm
  • Width: 520mm
  • Depth: 495mm
  • Power Consumption: 627 Watts
  • Weight: 40kg

The Arida 1500P dehumidifier is among the most advanced air dehumidifiers currently available. It boasts the same excellent construction and performance as the Arida 1500 but with the added benefit of a built in pump out system.


ASE 200 - Desiccant Dehumidifier

ASE 200 Desiccant Dehumidifier

19 Litres per day@saturation

  • Height: 285mm
  • Width: 290mm
  • Depth: 395mm
  • Power Consumption: 694 Watts
  • Weight: 14kg

The latest generation of adsorption dryers, energy-saving and powerful. Convenient, compact, robust stainless steel construction. Built-in hydrostat in the intake enables precision drying. Up to 30 % less power consumption with the same dehumidifying performance as conventional units without ECODRY rotors.


ASE 300 - Desiccant Dehumidifier

ASE 300 Desiccant Dehumidifier

26 Litres per day@saturation

  • Height: 370mm
  • Width: 333mm
  • Depth: 430mm
  • Power Consumption: 1040 Watts
  • Weight: 18kg

The latest generation of adsorption dryers, energy-saving and powerful. Convenient, compact, robust stainless steel construction. Built-in hydrostat in the intake enables precision drying. Up to 30% less power consumption with the same dehumidifying performance as conventional units without ECODRY rotor.