Advanced Cooling Technologies, Inc. (ACT) of Lancaster PA has been awarded a large manufacturing contract to deliver twenty air-to-air heat pipe heat exchangers (AAHXs) for use at a hospital in South Korea. The AAHXs will be incorporated into the hospital heating, ventilation, and air conditioning (HVAC) system. Ten of the AAHXs are large side-by-side units and nine of the AAHXs are unique, space-saving split and bent design. The remaining AAHX is an innovative, center split, passive loop thermosyphon, measuring over 27 feet long by 12 feet high and will be assembled and charged on-site by the ACT installation team.
Maintaining a high level of indoor air quality requires a significant amount of ventilation air. Stale indoor air must be frequently exchanged with fresh outside air. This outside air that is brought into the building must be heated in the winter and cooled in the summer by the active HVAC system to maintain the indoor air temperature at about 70°F. The heating and cooling of the outside air requires a tremendous amount of energy for a large building like the hospital.
At the same time as outdoor air is being drawn into the building, an equal amount of indoor air at 70°F is being discharged from the building. These two air streams pass through ACT’s heat pipe heat exchangers. In the winter, the warm discharge air transfers its heat energy passively to the incoming outside air so that the demand on the active heating and cooling system is significantly less. The AAHXs for this project have ten rows of heat pipes and are capable of performing approximately 70% of the precooling or preheating required. The twenty AAHXs will condition over 500,000 cubic feet of ventilation air per minute. The energy recovered by the AAHXs will save the hospital approximately $200,000 per year in energy costs.