This program will assist the HVAC design engineer in the proper selection of an Air-to-Air Heat Pipe Heat Exchanger (AAHX) and provide energy savings estimates. This tool is intended to provide the designer with the capability to perform a preliminary design selection and to evaluate and rate the AAHX’s performance at various design conditions. It is also intended as a tool to communicate engineering requirements to ACT for additional evaluation and optimization of the selection. The “Selection” is then the basis for preparing a quotation. If the selection tool does not provide the performance results necessary to meet your requirements, please contact ACT’s engineering experts to assist with your specific application.

Initial Selection of Design Conditions and Choice of Variables:

SOLUTION PARAMETERS: There are two modes (SELECT) or (RATE). In SELECT mode, the calculator will provide the
number of rows and fins per inch required to meet your input conditions. In the RATE mode, the calculator will provide the
output temperatures of the air streams based on the input conditions.

CALCULATION UNITS: Under PROJECT INFORMATION select either IP for ºF or SI for ºC.

LIMIT FIN RANGE: Under SOLUTION PARAMETERS there is a slide bar with two blue position tabs. Simply slide the tabs along the bar to select an FPI range or a specific FPI count.

User Selectable Variables:

OUTSIDE AIR DB/WB: Enter (if known) or select the nearest city under the PROJECT INFORMATION tab.

RETURN AIR DB/WB: Enter the conditioned space return air DB/WB values. (75°F/62.5°F is a good starting point if the exact conditions are unknown).

SUPPLY AIR DB / EFFECTIVENESS: In the SELECT mode, enter the desired supply air DB temperature or the desired effectiveness of the HP-AAHX. In the RATE mode, these values are calculated.

SUPPLY AIRFLOW: Enter the supply side airflow (SCFM). Note: Supply and return airflows values do not need to match.

RETURN AIRFLOW: Enter the return side airflow (SCFM).

FIN HEIGHT AND LENGTH: On the supply side, enter both the fin height and the finned length. On the return side, enter only the finned length. The fin height will be equal to the supply side. The finned lengths do not need to match.