Frequently Asked Questions

A refrigerative dehumidifier operates by drawing air over the evaporator coil, which transfers heat energy from the air to the refrigerant within the evaporator. As the heat energy is removed from the air, the moisture in the air condenses and the water drains into the condensate pan and down the drain. The cool, dry air passes through the reheat coil condenser and reabsorbs the heat energy from the hot gas refrigerant. The warm, dry air is discharged into the space. Heat energy can also be transferred to alternate refrigerant condensers to provide space cooling or water heating as specified.

Swimming pool water evaporates into pool room air. This evaporation is moisture that condenses on any surface including windows that is at or below the dew point temperature in the pool room. This condensation can lead to deterioration of the surfaces, furnishings and the building itself, and create musty odors and mold growth.

Desert Aire markets and sells our products through manufacturers representatives. Please find your local representative by using the Find A Rep function in the Contact submenu of this website.

Pricing and assistance is available from your Desert Aire Representative. Please find your local representative by using the Find A Rep function in the Contact submenu of this website.

We have incorporated advances in technology and industry standards into our dehumidification systems that have led us to reconfigure and rename system offerings. The best way to meet your application needs is to contact your local Desert Aire manufacturers representative.
Please find your local representative by using the Find A Rep function in the Contact submenu of this website.

View the How to install an IO module video at https://youtu.be/sxzfjN4rPSQ

Desert Aire lead times vary by product line. Information on lead times is available from your Desert Aire Representative.
Please find your local representative by using the Find A Rep function in the Contact submenu of this website.

View How to install a CM3530 DDC controller in a Desert Aire ExpertAire unit video at https://youtu.be/qj0XbdnZHhA

A refrigeration based pool dehumidifier operates by drawing air over an evaporator coil, which transfers heat energy from the air to the refrigerant within the evaporator. As the heat energy is removed from the air, the moisture in the air condenses into water that drains into a condensate pan and down a drain. The cool, dry air passes through the reheat coil condenser and reabsorbs the heat energy from the hot gas refrigerant. The warm, dry air is discharged into the space. Heat energy can also be transferred to alternate refrigerant condensers to provide space cooling or pool water heating as specified. For swmming pool dehumidifier sizing see Application Note 10: Swimming Pool Dehumidifier Sizing for swimming pool load calculations.

Sizing an industrial dehumidifier involves establishing the project design conditions by answering questions and considering several factors: what is the best temperature and humidity for the application? After the design dry bulb temperature and humidity level has been established, check what the dew point is of these two conditions. What is the moisture load? After the worst case load is calculated the equipment is selected based on 100% of the calculated load or less. Other considerations include the size of the space, amount of outside air introduced, lowest temperature, existence of a vapor barrier and open liquid tanks. Desert Aire has developed a sizing tool that will calculate the moisture load of many industrial applications. The method used is based on the ACCA Manual N and ASHRAE formulas. Our Tech Bulletin 29 explains the information required and considerations for sizing an industrial dehumidifier. 

Desert Aire dehumidification systems use either R-410A or R-407C.

Desert Aire Representatives are trained to provide application assistance for any application.
Please find your local representative by using the Find A Rep function in the Contact submenu of this website.

Desert Aire dehumidifiers are not EnergyStar rated since the EnergyStar program does not cover the systems we build. The current EnergyStar program for dehumidifiers is limited to the free standing portable type (non-ducted) with compressor sizes less than 12,000 Btu/hr or less than 2 lb/hr of moisture removal. This program was an offshoot of the AHAM rating program for home appliances.

The EnergyStar program has not provided a rating system as of yet for the large systems that require more fan motor horsepower to overcome the static of supply and return air duct work. AHRI has created two standards to rate the moisture removal efficiency of larger dehumidifiers and Dedicated Outdoor Air Systems: AHRI 910 and 920 respectively are available from the ahrinet.org website.

The switch from HID to LED is the most common change. The biggest difference between HID and LED is the LED lighting produces significantly less radiant heat. Comparing the leaf temperature of a room with HID and LED lights shows the room with HID lights has leaf temperatures of 3-4 degrees F higher than the room temperature. The room with LED lighting will have leaf temperatures of 2-3 degrees lower than the room temperature. The reduction in leaf temperatures with LED lighting allows growers to raise the room temperature slightly.

The reduction in radiant heat in grow rooms with LED lighting results in the ability to raise the room temperature slightly.  The benefit of this is the DX system’s latent moisture removal capacity while reducing the sensible cooling in the room. One of the key factors in a lighting change is the corresponding change in temperature and humidity set points. The performance of HVACD systems is greatly impacted by the lighting choice and set points. Always review every room condition calculation when making a change in plant count, lighting, watering or anything in a cultivation room and determine how it affects the HVACD system, its capacity, settings, and performance.

Chilled water dehumidification uses cold water from a chiller generally below 42F° (16°C) as the fluid to remove moisture from an airstream.  As the air is cooled below saturation, water is condensed out of the air.  The colder the water the more moisture can be removed.

One advantage of a chilled water system is it is generally easier to plumb water piping than it is refrigerant piping. Recovered energy can be easily be reused in all parts of a facility. Chillers have a better energy efficiency.

One disadvantage is the chiller/air handler system will be more expensive than a D/X refrigeration based system.

Most dehumidifiers use a refrigerant direct expansion (D/X) technology that the airstream flows across. The refrigerant makes the evaporator coil very cold and then condenses water from the air moving over it.  This technology is used for 45% to 65% relative humidity targets. 

Desiccant wheel systems use a specialty absorption type of wheel to remove humidity in applications requiring low humidity ranges below 40% RH.  After the water is absorbed by the wheel it rotates to second air stream that uses heat to remove the water.

In concept, a chilled water system can be used in any size facility.  However, the cost to install and maintain for small facilities is not normally practical.

In general, facilities larger than 100,000 square feet with demands greater than 200 to 300-ton cooling load or larger will consider chilled water systems

Natural gas chillers provide both the chilled water and hot water necessary for the GreenAire to function. These types of chillers also help reduce the electrical connect load for the facility.

Desert Aire’s GreenAire system can use any type of chiller that produces water below 42°F (16°C) and heat recovery chillers, absorption chillers and natural gas chillers.

A heat recovery chiller uses the internal refrigerant to capture some or all of the waste heat and use it to heat a second water loop up to 100°F to 120°F (37°C to 49°C) for use by the GreenAire system

While it is important for a design engineer to calculate the exact hot water load, a general rule of thumb is only 50% of the chiller must be used for heat recovery, lower its cost.

It is highly recommended to use a minimum of two or three chillers for the facility providing redundancy. These chillers can be plumbed together to be used for the entire facility. A design subset of chillers are modular chillers which can be sized to provide many layers of redundancy.

Pool water evaporates into poolroom air. This evaporation is moisture that condenses on any surface including windows that is at or below the dewpoint temperature in the poolroom. This condensation can lead to deterioration of the furnishings and the building itself, musty odors and mold growth.

Using only outdoor air for your poolroom ventilation can be expensive and makes it difficult to control a poolroom's humidity level, and the rate of evaporation from the pool surface. In some areas, outdoor air will often contain more moisture than the air inside the poolroom. Introducing humid outdoor air only increases the moisture content of the air inside the poolroom where it condenses on surfaces that are cooler than the dewpoint temperature. This condensation can lead to deterioration of the furnishings and the building itself while causing odors and promoting mold growth.

Conversely, introducing outdoor air that is too dry into a poolroom can accelerate evaporation of the pool water. In addition to the expense of adding water and water treatment chemicals to the pool, the accelerated evaporation makes swimmers feel chilled when their skin quickly dries upon leaving the water. Desert Aire dehumidification systems provide optimum control of humidity in your poolroom environment to safeguard the comfort and health of building users; protect furnishings and building systems; and conserve energy, water and water treatment resources.

Several Desert Aire dehumidification systems are available for poolroom applications. For help in sizing and choosing the system that is best for your needs, please contact a Desert Aire Representative. To find your local representative, please use the Find A Rep function in the Contact submenu of this website.

Desert Aire's SelectAire and SelectAire Plus dehumidification systems are specified for large indoor pools, aquatic centers and natatoriums. Desert Aire SelectAire (SA) Series systems are flexible in their design options and can be customized for specific applications. For example, SA Series systems can be installed indoors or outdoors; equipped with or without energy recovery systems; and equipped with or without outdoor air box systems for ventilation air.  

Desert Aire SelectAire Plus (SP) series can be applied to the same types of installations but has enhanced features for energy efficiency and control.  In addition to the unique heat-pump type energy recovery of all SelectAire systems, the SP series has double-wall foam-injected casing, self-balancing direct-drive plenum fan arrays for both supply and exhaust, and a wrap-around heat-pipe for enhanced moisture removal efficiency among many other enhanced features.

Desert Aire Representatives are trained to help you select the appropriate dehumidifier for your application. Answers to the following questions are needed at a minimum to properly determine the best Desert Aire solution for your poolroom application:
What is the surface area of each pool or whirlpool within the poolroom?
What is the square footage of the poolroom?
What is the average ceiling height of the poolroom?
What is the temperature at which each pool will be maintained?
What is the temperature at which the poolroom will be maintained?
Is there a separate spectator area as part of a larger space?

As a general rule, the temperature should be maintained at about 2° F above the water temperature. It is Desert Aire's recommendation that the air temperature should not be above 86° F.

It is recommended that the relative humidity be maintained at between 50% and 60% in the poolroom.

Outdoor air is introduced into a dehumidification system after the evaporator coil for several reasons. During the winter cold outdoor air may cause condensation in return air at undesirable places in the system or ductwork. Also, the variability of the outdoor air will influence the design and performance of the evaporator coil. When colder outdoor air mixes with the return air from a poolroom, it lowers the mixed air conditions that flow over the evaporator coil. This lower condition reduces the capacity of the system and creates a variable, unpredictable moisture removal and cooling capacity. To eliminate these issues, Desert Aire’s outdoor air box introduces the outdoor air between the evaporator and hot gas reheat coil.

ExpertAire Series dehumidifiers are used wherever excess humidity is a problem. Common applications include residential and hotel poolrooms, water treatment and wastewater treatment plants, records storage areas, warehouses and manufacturing facilities.

ExpertAire dehumidifiers are designed to operate in air temperatures between 65° and 95° F (18° to 35° C).

ExpertAire Series dehumidifiers are available in a range of sizes designed to remove between 8 lbs/hour and 84 lbs/hour of moisture from the air at ARI standard 82° F / 60% RH. Your Desert Aire Representative is available to assist you with unit selection for your application.

Yes. ExpertAire Series dehumidifiers are compliant with AHRI's moisture removal efficiency (MRE) requirement for indoor pool applications.

Yes. The ExpertAire Series dehumidifiers are available with an outdoor air intake option.

DOAS is a dedicated outdoor air system. DOAS are used to introduce outside air into a space as specified by the mechanical design engineer. In many areas local building codes require that outdoor air be brought into the building to help improve indoor air quality for occupants.

Unfortunately, outdoor air can also introduce moisture into a facility and can create IAQ problems such as mold, mildew and an environment where viruses and other organisms can flourish. The key to preventing mold formation and IAQ problems is to control the humidity level inside the building. While a standard air conditioner is thermostat controlled to provide space cooling, it cannot accurately control the humidity levels.

Desert Aire's answers to this problem are our Aura™, VerticalAire™ and TotalAire™ systems, which are designed to introduce 100% outdoor air while precisely controlling space humidity and temperature levels.

Please contact your local Desert Aire Representative for help in selecting the Aura™, VerticalAire or TotalAire DOAS system that is best for your application.

Yes. All of Desert Aire DOAS solutions comply with AHRI's moisture removal efficiency (MRE) requirements and significantly exceed ASHRAE 90.1 2013 minimum energy efficiency ratings.

The SP Series units were designed to be an extremely high efficiency climate control unit tailored to large indoor pool facilities such as natatoriums or waterparks.  Other applications where high levels of dehumidification are possible if target air conditions are similar.

The SelectAire Plus design leverages the additional 25 years of innovation in design and manufacturing capabilities to increase the energy efficiency, ease of use, and environmental control.  The SP has an alternate airflow and coil arrangement to continue to provide the extremely effective energy recovery of the SelectAire system while eliminating the possibility of bypass air from the outdoor to the exhaust.  The SP also includes a wrap-around heat pipe to increase dehumidification capacity and efficiency.  

The combination of the SelectAire energy recovery and the enhanced dehumidification of the SelectAire Plus (SP) is a patent pending design. 

The SP Series unit contains two refrigeration circuits.  One is optimized for dehumidification, the other is optimized for heat recovery and cooling.  The control logic in the machine senses the space requirements and shifts the operation of each circuit and the airflow in the machine to use the most efficient methods to condition the space. 

Direct drive fan arrays, scroll compressors, and heat exchangers that use the refrigerant directly to exchange energy with the air are also important to reducing energy use.  

R-410A refrigerant

Some equipment manufacturers divert the refrigerant gas to and air-to-water heat exchanger then move that water to another water to air heat exchanger to condition the air.  Although it may be easier to design a system this way, it is much less efficient.  The compressor needs to work harder since it is more difficult to transfer the energy.  There are also additional pumps, valves, control, and heat exchangers to fail.  The SelectAire Plus is designed to directly exchange the energy from the refrigerant heat exchangers to the air.  This reduces complexity and increases energy efficiency.  

Dampers and fans are self-balancing and are factory programmed for the flow rates at the time of order.  Commissioning consists of reviewing the flow rates programmed on the units display terminal and ensuring that the field-installed ductwork allows the airflow programmed.  

SP Series units are available in packaged air-cooled models up to the SP80 model size. This is an industry exclusive.

Typical dehumidifiers work best in high ambient temperature conditions of between 65 to 95 degrees F (18 to 35 degrees C) and 50 to 80% relative humidity while the LW Series dehumidifiers are designed to operate in low temperature applications of 32 to 70 degrees F (0 to 21 degrees C).

The LW Series dehumidifiers are available in sizes ranging from 3 to 15 nominal tons.

All SP Series units come as a completely assembled system.  Only the longest units that will not fit on a drop-deck flatbed in one piece have a filter section that needs to be easily connected in the field (no refrigeration work!).  

Optionally, the units can come in several sections that allow for lower weight per section and smaller size.  These are pre-designed sections that have been specifically created to allow for minimized cost and field labor.  See the General Arrangement drawings for the size and weight of the optional sections.  

Specially designed sectioned systems are available for extreme cases.  Contact your Desert Aire Representative for more details.

R-407C refrigerant

The LW Series units are for low temperature applications ranging from 32 degrees F to 70 degrees F (0 to 21 degrees C).

To prevent the evaporator coil from freezing in low temperature conditions, the LW Series dehumidifiers are designed with a timer that will initiate the defrost cycle when the suction line temperature drops below 30 degrees F (-1 degree C). During the defrost cycle the blower is disengaged and all of the system's reheat capacity is diverted to the evaporator, where it quickly thaws the coil. Once the suction line temperature increases to confirm the evaporator coil has thawed, the dehumidifier can resume normal operation.

Due to the wide variety of configurations, exploded view drawings are not presently available.

Call Desert Aire's Service Department at 1-262-946-7400 weekdays between 8:00 am and 5:00 pm Central time.

With the exception of compressors, we can generally ship in-stock parts for next day delivery when the order is placed before noon. Expedited freight charges are at the customer's expense.

Call Desert Aire's Service Department at 1-262-946-7400 weekdays between 8:00 am and 5:00 pm Central time.

Call Desert Aire's Service Department at 1-262-946-7400 weekdays between 8:00 am and 5:00 pm Central time.

To download Installation & Operation Manuals, go to the Service & Support area of this website and click on Installation & Operation Manuals.

Call Desert Aire's Service Department at 1-262-946-7400 weekdays between 8:00 am and 5:00 pm Central time.

A psychrometric chart shows physical and thermal properties of moist air on a graph where dry bulb temperatures, a humidity ratio (moisture content) scale, is shown as vertical lines and the horizontal lines show the dew point temperatures or the saturation temperature at which a vapor changes into liquid or condensation.  Learn more about the psychrometric chart in our Technical Bulletin#3. 

To load or update a program to a controller, follow the instructions in this video.

Using an existing Desert Aire R-22 remote condenser with a Desert Aire replacement R-410A dehumidifier is strictly dependent upon which model of Desert Aire remote condenser you're currently utilizing. If the existing remote condenser cannot be used, a new one must be purchased from Desert Aire. The following is a list of all Desert Aire basic remote outdoor condenser models and indicates whether they're compatible with one of our R-410A systems.

Model RC: No.

Model ROC: No.

Model ROCF: Yes.

Model ROCH: Yes.

Model ROCQ: Yes.

Please note that the R-22 systems use different refrigeration oil than R-410A and therefore all traces of oil and R-22 refrigerant must be removed prior to conversion to R-410A.

Using an existing Desert Aire R-22 remote condenser with a Desert Aire replacement R-410A dehumidifier is strictly dependent upon which model of Desert Aire remote condenser you're currently utilizing. If the existing remote condenser cannot be used, a new one must be purchased from Desert Aire. The following is a list of all Desert Aire basic remote outdoor condenser models and indicates whether they're compatible with one of our R-410A systems.

Model RC: No.

Model ROC: No.

Model ROCF: Yes.

Model ROCH: Yes.

Model ROCQ: Yes.

Please note that the R-22 systems use different refrigeration oil than R-410A and therefore all traces of oil and R-22 refrigerant must be removed prior to conversion to R-410A.

AireGuard is Desert Aire’s remote monitoring and alarming tool that allows a user to easily monitor the performance of the dehumidifier on a cloud-based database at any computer or portable device. All that is required is an Ethernet Internet connection directly to the Desert Aire operating controller.

Information security is maintained since this is a cloud based system where the client computer only accesses the remote data servers. The unit controller transmits data to and from the cloud storage location. Communication at the controller takes place on port 80, the same port that any computer uses to communicate with the web. The existing LAN firewall is maintained and no action from the IT department is required as long as the facility has internet access.

Users log onto the cloud-based service to view and interact with data. No further access to your local network is required. This connection will meet all of your IT department’s security requirements. LC, LV, and LCQ Series products have an onboard Ethernet connection as standard.

The AireGuard interface easily brings the read and write variables in real time to the display screen. It allows the user to adjust set points remotely as well as monitor all the operating variables.

The Desert Aire LC/LV/LCQ Series have another feature that allows the local display interface to be duplicated on the cloud based interface. This feature allows for remote startup capabilities by Desert Aire employees.

Since the refrigeration system of a dehumidifier is very complex, many owners hire outside firms to maintain their HVAC units. The alarm management feature of AireGuard provides the owner with email or SMS notifications at time of occurrence. With appropriate access to the Desert Aire dehumidifier unit via the cloud, the servicing contractor or Desert Aire may be able to evaluate the unit’s alarm with corrective action without visiting the site.

AireGuard is included with each LC/LV/LCQ unit and includes a two year subscription to the cloud data storage. Renewal subscriptions can be purchased after expiration.

Yes, Desert Aire units are available with AireGuard, Desert Aire's remote monitoring and alarming tool that allows a user to easily monitor the performance of the dehumidifier on a cloud-based database at any computer or portable device.

Information security is maintained since this is a cloud based system where the client computer only accesses the remote data servers.

Users log onto the cloud-based service to view and interact with data. No further access to your local network is required. This connection will meet all of your IT department’s security requirements. LC, LV, and LCQ Series products have an onboard Ethernet connection as standard.

The AireGuard interface easily brings the read and write variables in real time to the display screen. It allows the user to adjust set points remotely as well as monitor all the operating variables.

The alarm management feature of AireGuard provides the owner with email or SMS notifications at time of occurrence. With appropriate access to the Desert Aire dehumidifier unit via the cloud, the servicing contractor or Desert Aire may be able to evaluate the unit’s alarm with corrective action without visiting the site.

AireGuard is included with each LC/LV/LCQ unit and includes a two year subscription to the cloud data storage. Renewal subscriptions can be purchased after expiration. View the AireGuard brochure.