Van Air EMD Series cycling refrigerated compressed air dryers provide a consistent dew point when running at less than the design capacity. Since the actual energy cost is directly related to the amount of air dried, energy savings is maximized. For example, in a pneumatic system designed to dry 1000 SCFM, a cycling refrigerated air dryer running at 75% of the design capacity would save approximately $1,000 per year in electrical energy costs versus a non-cycling dryer. At 50% of design capacity, the savings would increase to $2,000 per year.

EMD Series cycling refrigerated compressed air dryers use direct expansion cooling to prevent dew point spikes, an inherent problem for competitive models using a thermal mass design. In thermal mass dryers, a refrigerant is used to cool a mass. This mass is then used to cool the compressed air. The time required to cool the mass delays cooling of the compressed air, resulting in dew point spikes up to 60° F that last 30 minutes or longer. These dew point spikes allow for extensive moisture carryover throughout the system.

In contrast, the Van Air cycling refrigerated dryer maintains a constant dew point temperature which helps eliminate moisture carryover. The constant dew point temperature provided by our EMD Series cycling refrigerated air dryers can be achieved because of its unique flooded evaporator design. Unlike competitive thermal mass dryers, we display a digital readout of the air dew point temperature on the cycling refrigerated dryer and issue a written guarantee of dew point performance.

Standard units are available from 80 through 8,000 SCFM. Custom units are available up to 25,000 SCFM. The capacity of the EMD Series cycling refrigerated compressed air dryer is based on operating conditions of 100° F inlet air temperature, 100° F ambient temperature and 100 PSIG operating pressure. Dryers rated for higher pressures or other operating conditions are available.

• Cycling refrigeration compressor results in maximum energy savings
Savings are directly related to the amount of air dried. A Model EMD-1250 running at 75% or design capacity will save $1,100 per year in electrical energy costs versus a non-cycling unit. The savings increase to $2,200 per year if the air dryer is operating at 50% of design capacity.

• Continuous Dew Point Temperature Readout
The EMD PLUS Series dryers display the precise dew point temperature on the control panel to allow easy monitoring of dryer performance.

• Direct Expansion Cooling Prevents Dew Point Spikes
Refrigerant directly cools the compressed air. In contrast, thermal mass type dryers and other competitive models inefficiently use refrigerant to cool a mass, which in turn cools the compressed air. The time required to cool the media delays cooling of the compressed air, resulting in dew point spikes up to 60° F that last 30 minutes or longer, allowing extensive moisture carryover.

When glycol or sand absorb heat, there is no latent heat involved. Therefore, the temperature and dew point must rise. The EMD maintains a constant dew point temperature because of its unique flooded evaporator design.