Manage the Outdoor Air Moisture Load

Outdoor air represents the largest source of moisture in most buildings. On hot and humid days, Airxchange energy recovery components dehumidify outdoor air without condensation. On cold and dry days, Airxchange energy recovery components humidify the outdoor air minimizing the need for additional building humidification.

Combined Systems Can Achieve Humidity Control

An Airxchange energy recovery component combined with standard HVAC systems is likely to control humidity in even the most humid climates. A Tiax, LLC report provides further details. By avoiding the expense of additional mechanical dehumidification helps pay for the Airxchange energy recovery component.

Moisture Removal Capacity Comparison

 OA ConditionsOA Moisture LoadDX System (20 Tons DX)DX/ERV System (15 Tons DX, 5 Tons ERV
 95ºDB,78ºWB7.1 gals/hour6.3 gals/hour9.6 gals/hour (4.9 from ERV)
87ºDB,80ºWB10.8 gals/hour7.6 gals/hour13.3 gals/hour (13.3 from ERV)
 75ºDB, 72ºWB 7.2 gals/hour 9.1 gals/hour 11.5 gals/hour (4.7 from ERV)

Calculations assume a 20 ton load with 2000 cfm of outdoor air with indoor design condition of 75/63.. SHR of DX was assumed to be .75 for 95/78 condition, .70 for 87/80 condition, and .65 for 75/72 condition. Airxchange energy recovery components assumed effectiveness of 70%.

Airxchange Humidification Examples:

 OA Conditions Moisture Loss Due To Outdoor Air Airxchange Humidification
 26ºDB, 25ºWB  7.3 gals/hour 5.3 gals/hour
 -4ºDB, -5ºWB  9.8 gals/hour 7.2 gals/hour
 -16ºDB, -17ºWB  10.1 gals/hour  7.5 gals/hour

Calculations assume 2000 cfm of outdoor air with indoor design condition of 72/54. Airxchange energy recovery components assumed to have effectiveness of 70%