What does DEVap mean?
DeVAP stands for Desiccant Enhanced Evaporative and is a relatively new form of air conditioning that has the potential to completely change the way we heat and cool buildings. Following is an overview of how it works, what its benefits are, and why HVAC techs should learn about it.
How does DEVap work?
Founded in the U.S. Department of Energy’s National Renewable Energy Laboratory, DEVap, uses technology that removes the use of environmentally harmful coolant chemicals while reducing energy costs. DEVap uses desiccant in liquid form and an evaporative cooler together to cool a room.
How does desiccant cooling work?
The operation of a desiccant cooling system is based on the use of a rotary dehumidifier (desiccant wheel) in which air is dehumidified. The resulting dry air is somewhat cooled in a sensible heat exchanger (rotary regenerator), and then further cooled by an evaporative cooler.
Where in the HVAC system is a desiccant used?
The desiccant adsorbs water vapor from the air downstream of the cooling coil, enabling the system to deliver drier supply air (at a lower dew point) without lowering the coil temperature. The regeneration side of the wheel is located in the mixed air, upstream of the cooling coil.
What is desiccant in HVAC?
Desiccants are a group of adsorbent materials that have a great affinity for water vapour. Due to this merit, desiccant material can produce hot and dry air which can be used for the drying process as well as in air-conditioning applications to minimize the latent heat load.
How long does a desiccant wheel last?
Desiccant wheels work longer and more efficiently: 100% pure molecular sieve desiccant. Desiccant wheel warranties range up to 5 years. Actual useable life can be up to 15 years.
What is HVAC desiccant?
In HVAC applications, desiccant wheels were historically used to dehumidify outdoor air brought indoors for ventilation. A desiccant wheel removes moisture from the process air stream—but for every Btu of latent heat (moisture) removed, it adds more than one Btu of sensible heat.
What is the role of desiccant?
Desiccants are commonly used to keep products dry and stable. Dry desiccants can absorb moisture from air either by physical adsorption or by chemical reaction, and thus reduce the humidity in the headspace of sealed containers.
Why do dehumidifiers fail so quickly?
Overload. If your dehumidifier is no longer pulling water from the air and you have verified that the ambient room temperature is above 65 degrees Fahrenheit, then the unit’s compressor may not be running. A common cause for the overload to fail is from operating the dehumidifier on long or undersized extension cords.
Can you clean a desiccant wheel?
Wash the segments or small wheels in a 5% solution of non-acid based coil cleaner or alkaline detergent and warm water. Soak in the solution until grease and tar deposits are loosened (Note: some staining of the desiccant may remain and is not harmful to performance).
Do desiccants work?
Desiccant products are of great use where the rate of evaporation is quite low due to the high percentage of humidity in the atmosphere. Desiccants are also called Dehumidifiers as they absorb the extra amount of moisture from the air to keep it dry and hygienic.
Do desiccants expire?
There’s no expiration date. The gel packets can be “dried out” when they are full of moisture and reused. Silica gel will absorb moisture from any environment, so a sachet left out in the open will immediately start taking up water vapour.
Why is devap important to the HVAC industry?
DeVAP is a visionary technology that has the potential to take the HVAC world by storm. Its simple yet revolutionary approach to cooling air enables companies and homeowners to keep their structures cool and dry for only a small percentage of what it would cost them if they used traditional air conditioning systems.
What kind of coolant does devap air conditioning use?
DeVAP air conditioning, on the other hand, does not use these deleterious coolant chemicals. Instead, it uses a liquid form of desiccant (you may know it in the form of the little “Do not eat” packets that come in shoe boxes) in combination with cutting edge evaporation technology to remove humidity from the air.
How does the desiccant work in the devap process?
The desiccant creates dry air using heat, while the evaporative cooler turns dry air into cold air; the desiccant and evaporative cooler work together to create cold-dry air. The U.S. Department of Energy provides a full report on the DEVAP process.