What is a common feature of both HRVs and ERVs?

Both heat recovery ventilators (HRVs) and energy recovery ventilators (ERVs) share the common feature of delivering outside air into the home. This function is essential for maintaining indoor air quality and is particularly important in modern energy-efficient homes, where airtight construction can restrict fresh air circulation.

HRVs focus on exchanging heat between the outgoing stale air and the incoming fresh air, helping to pre-condition the incoming air, which can reduce heating costs in colder climates. Similarly, ERVs not only exchange heat but also transfer moisture, making them beneficial in climates where humidity control is a concern.

The other options do not accurately reflect a feature that is common to both systems. For instance, while they both facilitate air exchange, neither system is primarily designed for heating air. Additionally, they typically use specialized filters designed to capture finer particles rather than standard filters. Finally, both systems usually require electrical components to operate efficiently, further distinguishing them from options that suggest they operate without such systems.