What type of systems improves indoor air quality without significant energy loss?

Energy-recovery ventilation systems are designed specifically to enhance indoor air quality while minimizing energy loss. These systems work by exchanging stale indoor air with fresh outdoor air in an efficient manner. The key feature of energy-recovery ventilation systems is their ability to transfer heat and moisture between the incoming and outgoing air streams.

During winter months, these systems can capture heat from the outgoing warm air to warm up the incoming cold air, thus reducing the energy required to heat the space. Similarly, in summer, they can help cool the incoming air by transferring some of the heat contained in it to the outgoing warm air. This heat exchange process ensures that the indoor environment remains comfortable without the need for excessive energy expenditure on heating and cooling.

In contrast, heat recovery systems, while also effective, may not always provide the same level of moisture control that energy-recovery systems do, which is vital for maintaining comfortable humidity levels in different weather conditions. Standard exhaust fans generally do not recover energy and can lead to increased heating or cooling costs by pulling conditioned air outside without any means of retaining energy. Air purifiers are limited to filtering particles from the air and do not actively exchange indoor and outdoor air, which means they do not contribute to air quality improvement through ventilation or energy efficiency.