When should a desiccant be replaced?

We recommend that a desiccant be replaced once every three years for open-cycle systems and once every two years for closed-cycle systems. A desiccant may degrade more quickly depending on the environment where it is used. Dew point temperatures offer a good indication for when to replace your desiccant.

How do you clean desiccant wheels?

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).

How do you know if desiccant is bad?

A good indicator of desiccant condition is to use a portable hygrometer on the downstream airline to see what actual dewpoint is being achieved. Another indicator that desiccant is going bad is quicker than normal loading on the particulate filter downstream.

Can you regenerate desiccant?

Many molecular sieves are used as desiccants. Silica gels can be regenerated heating up to 180°F, whereas molecular sieves can be regenerated by heating them to up to ~550°C, it will release the trapped water. This process is called regenerating the desiccant.

How long do desiccant beads last?

The life of these bags depends on the environment that they are exposed to, but most desiccant bags last between 1 and 3 years. When silica gel absorbs moisture, it goes from being in an active state to an inactive state. When this happens, it just needs to be reactivated so that it can be used again.

How do you revitalize desiccant?

Heat the oven to 300 degrees centigrade. Place the wet desiccant in the glass dish. Put on gloves and place the desiccant in the oven. Allow the desiccant to cook for at least six hours.

What does an energy recovery wheel do?

In winter, as exhaust air passes through the ERV, energy is captured by the wheel. As the wheel rotates into the incoming airstream, energy is released by the wheel to heat and humidify the incoming airstream closer to indoor conditions, reducing unit workload and energy consumed by the heating system.

How does a Munters dehumidifier work?

Munters desiccant dehumidification systems remove moisture from the air by using a desiccant, a material which easily attracts and holds water vapor. Desiccant dehumidifiers are especially well-suited for removing moisture from air at a low temperature and low humidity level.

Do desiccant packets go bad?

Silica gel has no expiry date, it is effectively sand which obviously doesn’t expire. However, over time they will absorb moisture and become less effective. You can put the silica gel packs in the oven in order to release the moisture and reuse them over and over.

Why does desiccant say do not eat?

Desiccant silica gel is a choking hazard. Also, if eaten in large quantities, desiccant silica gel may cause intestinal obstruction. This is why manufacturers often label the packets with “Do not eat” or “Throw away after using”.

Can you microwave desiccant?

Do not go over 300-degrees in the standard oven or 900-watts in a microwave. You will damage the silica gel and it will lose its absorbency. Heating the packets over 245-degrees will damage the packaging.

Does desiccant stop working?

There’s no expiration date. The gel packets can be “dried out” when they are full of moisture and reused. Look for how to do this on the web.

When do you need to replace a desiccant wheel?

Desiccant wheel replacement should be considered when: Cleaning/replacing filters does not help and air flow from regeneration blower is good Desiccant wheel replacement: Some manufacturers require that a complete rotor wheel assembly be ordered for replacement Other manufacturers sell just the desiccant wheel replacement, which is less expensive

How are desiccant wheels used in air dehumidification?

The desiccant wheels are not only used for air dehumidification, but also for enthalpy recovery. When it is used for enthalpy recovery, there is no heater and it rotates between process air and exhaust air to facilitate the transfer of heat and humidity between the streams.

When is a desiccant wheel called an active wheel?

The desiccant wheel is called a passive desiccant wheel or enthalpy wheel or rotary energy wheel, when there is no regeneration air heater. It is called an active desiccant wheel when it is provided with an air heater and the regeneration and process air side are separated by clapboard.

How is the enthalpy wheel used in a desiccant wheel?

When it is used for enthalpy recovery, there is no heater and it rotates between process air and exhaust air to facilitate the transfer of heat and humidity between the streams. So the enthalpy wheel is used in winter to recover heat and moisture from the exhaust air, whereas in summer it is used to cool and dehumidify the process air.