Keep it simple – KeepTheHeatTM
The KeepTheHeatTM system is designed to economically provide ventilation air to commercial and industrial facilities. Many other options are available. KeepTheHeatTM is an air-to-air heat exchanger that will be the focus of this brief because its simplicity has received very positive reviews. The system provides fresh ventilation air at lower installation cost than many other heat exchanger systems. Fresh air is needed to maintain comfort in workstations, balance fume exhaust, and meet code requirements. Ventilation requirements, and their associated energy cost, can be especially significant for industrial facilities.
Traditional dedicated outdoor air systems typically heat outside air with direct-fire burners, and some heat exchanger systems tend to be expensive because of the heat exchanger material and ductwork construction.
How does it work?
The KeepTheHeatTM system uses two fans and two types of ductwork to bring fresh air to industrial workers. A distinctive “Y” fan configuration projects from the building’s sidewall such that the connected metal ductwork can run along the ceiling of the building interior. The bottom fan pulls warm exhaust air from the ceiling through the metal ductwork while the top fan pushes 1,500-cfm of fresh outside air into multiple corrugated tubes that run to individual workstations. This provides fresh air right where it is needed. Like all heat exchangers, heat from the warm exhaust air is transferred to the colder outside air during the winter. To a lesser degree, heat can move from hot outside air to warm exhaust air during the summer; thereby reducing cooling costs.
What are the most appropriate applications?
The KeepTheHeatTM system is installed in numerous industrial facilities with many references listed on the company’s website. Welding and other fabrication operations that require large amounts of ventilation and exhaust air may benefit from this system.
How effective is it?
The effectiveness of the KeepTheHeatTM system is not published, but the company’s website provides numerous temperature measurements that indicate the system is effective in transferring heat from exhaust air to cold outside air. The more effective a heat exchanger is, the more energy savings can be achieved. Utility incentives would likely come from custom rebate programs.
 ASHRAE 90.1-2007 specifies a minimum effectiveness of 50% for conditions that require an energy recovery system.